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Sample records for ammonium perchlorates

  1. Comparative DFT study of crystalline ammonium perchlorate and ammonium dinitramide.

    Science.gov (United States)

    Zhu, Weihua; Wei, Tao; Zhu, Wei; Xiao, Heming

    2008-05-22

    The electronic structure, vibrational properties, absorption spectra, and thermodynamic properties of crystalline ammonium perchlorate (AP) and ammonium dinitramide (ADN) have been comparatively studied using density functional theory in the local density approximation. The results shows that the p states for the two solids play a very important role in their chemical reaction. From the low frequency to high frequency region, ADN has more motion modes for the vibrational frequencies than AP. The absorption spectra of AP and ADN display a few, strong bands in the fundamental absorption region. The thermodynamic properties show that ADN is easier to decompose than AP as the temperature increases. PMID:18396853

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

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    Hongxia Chen

    2014-05-01

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

  3. Prediction of Particle Size of Ammonium Perchlorate during Pulverisation

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    Sunil Jain

    2006-07-01

    Full Text Available Ammonium perchlorate has been pulverised by an impact mill (air classifier mill to studythe influence of different operating parameters, viz., effect of mill speed, classifier speed, feedrate, and damper opening (suction rate on the particle size. Further based on the differentgrinding parameters, an empirical equation has been developed and used for the prediction ofparticle size. The experimental results indicate that the values are very close to the predictedones. In addition, particle size distribution has also been studied by applying different modelequations and it has been found that Rosin-Rammler model is the most suitable model for thisoperation.

  4. High Pressure Burn Rate Measurements on an Ammonium Perchlorate Propellant

    Energy Technology Data Exchange (ETDEWEB)

    Glascoe, E A; Tan, N

    2010-04-21

    High pressure deflagration rate measurements of a unique ammonium perchlorate (AP) based propellant are required to design the base burn motor for a Raytheon weapon system. The results of these deflagration rate measurements will be key in assessing safety and performance of the system. In particular, the system may experience transient pressures on the order of 100's of MPa (10's kPSI). Previous studies on similar AP based materials demonstrate that low pressure (e.g. P < 10 MPa or 1500 PSI) burn rates can be quite different than the elevated pressure deflagration rate measurements (see References and HPP results discussed herein), hence elevated pressure measurements are necessary in order understand the deflagration behavior under relevant conditions. Previous work on explosives have shown that at 100's of MPa some explosives will transition from a laminar burn mechanism to a convective burn mechanism in a process termed deconsolidative burning. The resulting burn rates that are orders-of-magnitude faster than the laminar burn rates. Materials that transition to the deconsolidative-convective burn mechanism at elevated pressures have been shown to be considerably more violent in confined heating experiments (i.e. cook-off scenarios). The mechanisms of propellant and explosive deflagration are extremely complex and include both chemical, and mechanical processes, hence predicting the behavior and rate of a novel material or formulation is difficult if not impossible. In this work, the AP/HTPB based material, TAL-1503 (B-2049), was burned in a constant volume apparatus in argon up to 300 MPa (ca. 44 kPSI). The burn rate and pressure were measured in-situ and used to calculate a pressure dependent burn rate. In general, the material appears to burn in a laminar fashion at these elevated pressures. The experiment was reproduced multiple times and the burn rate law using the best data is B = (0.6 {+-} 0.1) x P{sup (1.05{+-}0.02)} where B is the burn

  5. Tetranitroacetimidic acid: a high oxygen oxidizer and potential replacement for ammonium perchlorate.

    Science.gov (United States)

    Vo, Thao T; Parrish, Damon A; Shreeve, Jean'ne M

    2014-08-27

    Considerable work has been focused on developing replacements for ammonium perchlorate (AP), a primary choice for solid rocket and missile propellants, due to environmental concerns resulting from the release of perchlorate into groundwater systems [corrected]. Additionally, the generation of hydrochloric acid contributes to high concentrations of acid rain and to ozone layer depletion. En route to synthesizing salts that contain cationic FOX-7, a novel, high oxygen-containing oxidizer, tetranitroacetimidic acid (TNAA), has been synthesized and fully characterized. The properties of TNAA were found to be exceptional, with a calculated specific impulse exceeding that of AP, leading to its high potential as a replacement for AP. TNAA can be synthesized easily in a one-step process by the nitration of FOX-7 in high yield (>93%). The synthesis, properties, and chemical reactivity of TNAA have been examined.

  6. Nano-Ammonium Perchlorate: Preparation, Characterization, and Evaluation in Composite Propellant Formulation

    Science.gov (United States)

    Kumari, A.; Mehilal; Jain, S.; Jain, M. K.; Bhattacharya, B.

    2013-07-01

    Nanomaterials are finding applications in explosives and propellant formulations due to their large surface area and high surface energy. This high surface energy is responsible for the low activation energy and increase in burning rate of the composition. Therefore, a successful attempt has been made to prepare nano-ammonium perchlorate using a nonaqueous method by dissolving ammonium perchlorate (AP) in methanol followed by adding the dissolved AP to the hydroxyl-terminated polybutadiene (HTPB), homogenization, and vacuum distillation of the solvent. The nano-AP thus formed was characterized using a NANOPHOX particle size analyzer (Sympatec, Germany), transmission electron microscopy (FEI, Hillsboro, OR), X-ray diffraction (PANalytical B.V., The Netherlands) and scanning electron microscopy (Ikon Analytical Equipment Pvt. Ltd., Mumbai, India) for particle size, purity, and morphology, respectively. The thermal behavior of nano-AP was also studied using differential thermal analysis-thermo gravimetric analysis (DTA-TGA). The data indicated that the particle size of the prepared AP was in the range of 21-52 nm and the thermal decomposition temperature was lower than that of coarse AP. Characterized nano-AP was subsequently used in composite propellant formulation up to 5% with 86% solid loading and studied for different properties. The results showed a 14% increase in burning rate in comparison to standard propellant composition with desired mechanical properties.

  7. Change of iodine load and thyroid homeostasis induced by ammonium perchlorate in rats.

    Science.gov (United States)

    Chen, Hong-Xia; Ding, Miao-Hong; Liu, Qin; Peng, Kai-Liang

    2014-10-01

    Ammonium perchlorate (AP), mainly used as solid propellants, was reported to interfere with homeostasis via competitive inhibition of iodide uptake. However, detailed mechanisms remain to be elucidated. In this study, AP was administered at 0, 130, 260 and 520 mg/kg every day to 24 male SD rats for 13 weeks. The concentrations of iodine in urine, serum thyroid hormones levels, total iodine, relative iodine and total protein, and malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) activity in thyroid tissues were measured, respectively. Our results showed that high-dose perchlorate induced a significant increase in urinary iodine and serum thyroid stimulating hormone (TSH), with a decrease of total iodine and relative iodine content. Meanwhile, free thyroxine (FT4) was decreased and CAT activity was remarkably increased. Particularly, the CAT activity was increased in a dose-dependent manner. These results suggested that CAT might be enhanced to promote the synthesis of iodine, resulting in elevated urinary iodine level. Furthermore, these findings suggested that iodine in the urine and CAT activity in the thyroid might be used as biomarkers for exposure to AP, associated with thyroid hormone indicators such as TSH, FT4.

  8. Effect of Triethanolamine and Benzaldehyde on the Storage Stability of Polystyrene- Ammonium Perchlorate Propellant

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    K. Kishore

    1986-10-01

    Full Text Available The effect of triethanolamine and benzaldehyde on the stability of polystyrene has been studied by dynamic thermogravimetry (TG. Slower decomposition of polymer in the presence of these compounds indicates their inhibiting ability on the oxidation of the polymer. The burning rate measurements of polystyrene (PS/ammonium perchlorate (AP propellants at ambient temperature and pressure shows an increase with the storage time. The percentage change in the burning rate of the propellants containing aldehyde and amine is less during the ageing which indicates the increased stability of the propellants. The safe-life time of the propellants for the ballistic stability has been calculated from the activation energy for the ageing process using an Arrhenius type equation. The safe-life of the propellants containing triethanolamine and benzaldehyde is more than the neat propellant.

  9. Effect of hydrogen storage alloy on combustion properties of ammonium perchlorate /glycidylazide polymer -based propellant

    Science.gov (United States)

    Li, G. P.; Dou, Y. M.; Chai, C. P.; Luo, Y. J.

    2015-12-01

    Hydrogen storage alloys can serve as good potential fuels for propellant design, by improving the energy and combustion properties. The influence of hydrogen storage alloy (A30) on the combustion properties of ammonium perchlorate/glycidylazide polymer (AP/GAP)-based on propellant were studied. The results showed that A30 could increase the burning rate of propellants by 29.75% and 74.78%, compared with B30 and Al. The combustion model of AP/GAP-based propellant containing different fuel was built. Firstly, A30 reduced the high decomposition temperature and promote condensed phase reaction heat of AP. Secondly, A30 deduced the burning surface temperature. Thirdly, A30 might prove the explosive heat of propellant. Therefore, A30 could greatly improve combustion properties of AP/GAP-based propellant.

  10. A Consideration for Design of Ammonium Perchlorate/Hydroxyl Terminated Polybutadiene Composite Propellant

    Science.gov (United States)

    Kohga, Makoto

    Specific impulse and burning rate characteristics are the important properties for the propellant design. Because of the requirements for the preparation of ammonium perchlorate (AP)/hydroxyl-terminated polybutadiene (HTPB) composite propellant, there is an upper limit content, φ of AP contained propellant. Specific impulse and burning rate increase with increasing the AP content. The specific impulse, Ispφ and the burning rate, rφ of the propellant prepared at φ, rφ are the highest values of the propellant prepared with AP used as an oxidizer. It is necessary for the propellant design to estimate φ, Ispφ and rφ. The φ, Ispφ and rφ are closely associated with the specific surface area, Swp measured by air-permeability method. Therefore, these values are estimated with Swp. A process for the design of AP/HTPB composite propellant would be proposed in this study.

  11. Microscopic observations of X-ray and gamma-ray induced decomposition of ammonium perchlorate crystals

    Science.gov (United States)

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

    1972-01-01

    The X-ray and gamma-ray induced decomposition of ammonium perchlorate was studied by optical, transmission, and scanning electron microscopy. This material is a commonly used oxidizer in solid propellents which could be employed in deep-space probes, and where they will be subjected to a variety of radiations for as long as ten years. In some respects the radiation-induced damage closely resembles the effects produced by thermal decomposition, but in other respects the results differ markedly. Similar radiation and thermal effects include the following: (1) irregular or ill-defined circular etch pits are formed in both cases; (2) approximately the same size pits are produced; (3) the pit density is similar; (4) the c face is considerably more reactive than the m face; and (5) most importantly, many of the etch pits are aligned in crystallographic directions which are the same for thermal or radiolytic decomposition. Thus, dislocations play an important role in the radiolytic decomposition process.

  12. Effect of Surface Microstructure on the Temperature sensitivity of Burning Rate of Ammonium Perchlorate

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    K. Kishore

    1997-04-01

    Full Text Available Considering Vielle's law and the new thermodynamic model which the authors have developed recently the true dependence of temperature sensitivity of burning rate of ammonium perchlorate (AP on pressure is resolved and experimentally verified for bellet burning. The value of decreases with pressure steeply in regime I' (below 20 atm, but gently in regime I (above 20 atm. The value of powder AP has been determined and it is observed that (powder > (pellet, which clearly suggests that of is innuenced by the surface temperature sensitive parameter and hence by the surface/subsurface microstructure. In powder burning, the buoyant lifting of the particles into the gas phase occurs, Which constitutes the so-called 'free board region' (FER extending just above the true surface. Consequent to the decomposition of AP particles in FER, the condensed phase heat release gets curtailed and (powder becomes larger. A general relationship for in terms of density and surface temperature is suggested, which is applicable to both pellet and powder AP.

  13. Combustion Characteristics and Propulsive Performance of Boron/Ammonium Perchlorate Mixtures in Microtubes

    Science.gov (United States)

    Liang, Daolun; Liu, Jianzhong; Zhou, Junhu; Wang, Yang; Yang, Yuxin

    2016-07-01

    A microthruster is used for the operation tracking and posture control of microsatellites. In this work, the combustion characteristics and propulsive performance of a boron/ammonium perchlorate (B/AP) propellant mixture for a microthruster were investigated. Amorphous B and AP were used in different mass ratios to prepare the propellant samples. A laser-ignition solid micropropulsion test system was set up, and a differential scanning calorimeter was used. The solid combustion products of the samples with good performance were collected. Microstructural and component analyses of the combustion products were performed. Various performance parameters, including the combustion temperature, combustion velocity, spectral intensity, ignition delay time, thrust, specific impulse, density specific impulse, and heat flow, changed with the fuel-oxidant ratio. The optimal fuel-oxidant mass ratio of the propellant samples was 40%, with a density specific impulse of 0.474 kg/m2•s and a maximum heat flow of 4.4913 mW/mg. Analysis of the combustion products revealed that the clearance between particles significantly diminished after combustion. During combustion, the AP completely decomposed, and a large amount of H3BO3, B2O3, and HBO2 was generated.

  14. Size and Shape of Ammonium Perchlorate and their Influence on Properties of Composite Propellant

    Directory of Open Access Journals (Sweden)

    Sunil Jain

    2009-05-01

    Full Text Available Most of the composite propellant compositions contain solid loading up to 86 per cent. The main solid ingredients of composite propellant are ammonium perchlorate (AP and aluminium powder. Therefore, it is a must to characterise these to improve processibility and quality of composite propellant. Effect of particle size on propellants slurry viscosity and ballistic parameters are well documented, however, the effect of oxidizer particle shape is not reported. In the present study, different methods for size and shape characterisation are discussed and effect of size and shape of AP on composite propellant properties are studied. The data indicate that as size of AP decreases, propellant slurry viscosity increases and burn rate increases. The particles having higher shape factor provides less endof mix (EOM viscosity of propellant slurry and burn rate. Further, effect of size of ground AP on shape is also investigated. From the data thus obtained, it is inferred that as size of ground AP decreases, shape factor decreases, and particles become more irregular in shape.Defence Science Journal, 2009, 59(3, pp.294-299, DOI:http://dx.doi.org/10.14429/dsj.59.1523

  15. Biomarker expression in lung of rabbit with pulmonary fibrosis induced by ammonium perchlorate.

    Science.gov (United States)

    Wu, Feng-hong; Guo, Hui-xia; Lin, Ming-fang; Chen, Zhi-ze; Zhou, Xuan; Peng, Kai-liang

    2011-04-01

    Ammonium perchlorate (AP), an oxidizer, has been used in solid propellants. Although AP exposure has been suspected as a risk factor for the development of pulmonary fibrosis, data are still inconclusive. To evaluate the pulmonary toxicity and the potential pulmonary fibrosis caused by occupational exposure to this compound, 25 male rabbits were randomly allocated into five groups to receive AP or bleomycin or saline by intratracheal injection. All rabbits were sacrificed and total RNA from the lungs was extracted. Expressions of types I and III collagens, transforming growth factor-β(1) (TGF-β(1)) and tumour necrosis factor-α (TNF-α) messenger RNA (mRNA) were measured by reverse transcription-polymerase chain reaction (RT-PCR). The expressions of type I and III collagen mRNA in low, moderate and high dose AP groups were significantly higher (p < 0.01 or p < 0.05) than that in the saline group. There was also a significant increased level of TGF-β(1) and TNF-α mRNA in the three AP groups compared with saline control group (p < 0.01 or p < 0.05). These results reveal that AP can increase gene expressions of types I, III collagens, TGF-β(1) and TNF-α in lung of rabbits exposed to AP. The overexpression of these biomarkers were considered as effective indicator linking to the development of pulmonary fibrosis and finally demonstrated that AP has potential to induce pulmonary fibrosis.

  16. Preignition reactions of AP-HTPB propellants studied by IR spectrometry. [Ammonium Perchlorate-Hydroxyl Terminated PolyButadiene

    Science.gov (United States)

    Law, R. J.; Baer, A. D.; Ryan, N. W.

    1977-01-01

    IR absorption spectrometry was used to follow the disappearance of NH and CH bonds during the pyrolysis of a polymer film containing 30 weight percent ammonium perchlorate (AP). The remaining 70 weight percent consisted of a mixture of 92.5 weight percent hydroxyl-terminated polybutadiene (HTPB) and 7.5 weight percent isophrone diisocyanate (IPDI). The results indicate that polymer decomposition is induced by products of AP decomposition, and that about 2.5 CH bonds disappear for each NH bond that disappears. The diffusion process occurring in the later stages of the reaction is analyzed in an attempt to account for the unexpectedly low activation energy.

  17. On the adhesion between hydroxyl-terminated polybutadiene fuel-binder and ammonium perchlorate. Performance of bonding agents

    Energy Technology Data Exchange (ETDEWEB)

    Hori, K.; Iwama, A.; Fukuda, T.

    1985-12-01

    A simple method to evaluate the adhesive force between solid oxidizer and polymeric fuel-binder is presented. As an illustration, hydroxyl-terminated polybutadiene (HTPB) sticks including several different bonding agents are bonded on ammonium perchlorate (AP) single crystals, and stress-strain history unitl rupture occurs is obtained by applying uniaxial tensile stress perpendicularly to the adhesion surface. Further, whether each bonding agent reacts with AP or not was analysed with pursuing infrared absorption spectra. The hypothesis that the interfacial adhesive force arises from hydrogen bonding force is proposed.

  18. Preparation of Nano-MnFe2O4 and Its Catalytic Performance of Thermal Decomposition of Ammonium Perchlorate

    Institute of Scientific and Technical Information of China (English)

    韩爱军; 廖娟娟; 叶明泉; 李燕; 彭新华

    2011-01-01

    Nano-MnFe2O4 particles were synthesized by co-precipitation phase inversion method and low-temperature combustion method respectively, using MnCl2, FeCl3, Mn(NO3)2, Fe(NO3)3, NaOH and C6H8O7. X-ray diffraction (XRD), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), thermogravim-etry-differential thermal analysis (TG-DTA) and differential scanning calorimetry (DSC) were used to characterize the structure, morphology, thermal stability of MnFe2O4 and its catalytic performance to ammonium perchlorate. Results showed that single-phased and uniform spinel MnFe2O4 was obtained. The average particle size was about 30 and 20 nm. The infrared absorption peaks appeared at about 420 and 574 cm-1, and the particles were stable below 524 ℃. Using the two prepared catalysts, the higher thermal decomposition temperature of ammonium perchlorate was decreased by 77.3 and 84.9 ℃ respectively, while the apparent decomposition heat was increased by 482.5 and 574.3 J?g?1. The catalytic mechanism could be explained by the favorable electron transfer space provided by outer d orbit of transition metal ions and the high specific surface absorption effect of MnFe2O4 particles.

  19. A novel hydrolysis method to synthesize chromium hydroxide nanoparticles and its catalytic effect in the thermal decomposition of ammonium perchlorate

    International Nuclear Information System (INIS)

    Highlights: ► Synthesis of Cr(OH)3 nanoparticles in Cr3+–F− aqueous solution. ► The F− ion tailors coagulated materials, Cr(OH)3 nanoparticles are obtained. ► Adding nanosized Cr(OH)3, AP thermal decomposition temperature decreases to 200 °C. ► The nanosized Cr(OH)3 catalyzes NH3 oxidation, accelerating AP thermal decomposition. - Abstract: A procedure for the preparation of spherical Cr(OH)3 nanoparticles was developed based on the aging of chromium nitrate aqueous solutions in the presence of sodium fluoride, urea, and polyvinylpyrrolidone. Using scanning electron microscopy, transmission electron microscopy, and energy dispersive spectroscopy, the morphological characteristics of Cr(OH)3 were controlled by altering the molar ratio of fluoride ion to chromium ion, as well as the initial pH and chromium ion concentration. The prepared nanosized Cr(OH)3 decreased the temperature required to decompose ammonium perchlorate from 450 °C to about 250 °C as the catalyst. The possible catalytic mechanism of the thermal decomposition of ammonium perchlorate was also discussed.

  20. Synthesis of chrysalis-like CuO nanocrystals and their catalytic activity in the thermal decomposition of ammonium perchlorate

    Indian Academy of Sciences (India)

    Jun Wang; Shanshan He; Zhanshuang Li; Xiaoyan Jing; Milin Zhang; Zhaohua Jiang

    2009-11-01

    Chrysalis-like morphologies of CuO have been synthesized in large-quantity via a simple chemical deposition method without the use of any complex instruments and reagents. CuO nanocrystals showed a different morphology at three different temperatures, 25, 60 and 100°C. The particle size, morphology and crystal structure of the samples were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectra. The catalytic effect of CuO nanoparticles on the decomposition of ammonium perchlorate (AP) was investigated by STA 409 PC thermal analyzer at a heating rate of 10°C min-1 from 35 to 500°C. Compared with the thermal decomposition of pure AP, the addition of CuO nanoparticles decreased the decomposition temperature of AP by about 85°C.

  1. Effects of addition of surfactants on viscosity of uncured ammonium perchlorate(A/P)/hydroxyl-terminated polybutadiene (HTPB) propellant

    Energy Technology Data Exchange (ETDEWEB)

    Koga, M.; Hagihara, Y. [National Defense Academy, Kanagawa (Japan)

    1998-08-31

    In production of ammonium perchlorate (AP)/hydroxyl-terminated polybutadiene (HTPB) propellants, it is preferable that the uncured propellant has a low viscosity during the mixing and forming processes. In this study, effects of surfacant on viscosity of the uncured propellant are studied for a total of 11 types of surfacants. It is found that sodium lauryl sulfate decreases viscosity of the AP/HTPB mixture more efficiently than any other surfacants tested. Apparent viscosity decreases by 30%, and its optimum dosage will be 0.005wt% based on the mixture to sufficiently decrease viscosity of the mixture. Viscosity of the mixture can be also decreased by improving wettability between AP and HTPB prepolymer. Sodium lauryl sulfate also shows an effect of delaying the potlife, i.e., time extending from addition of a curing agent to a thermosetting resin until it is cured to be unserviceable. 6 refs., 4 figs., 2 tabs.

  2. Limited overshooting of NH{sub 4}{sup +} ions in ammonium perchlorate; Ograniczene przeskoki jonow NH{sub 4}{sup +} w nadchloranie amonowym

    Energy Technology Data Exchange (ETDEWEB)

    Birczynski, A.; Lalowicz, Z.T. [Inst. of Nuclear Physics, Cracow (Poland); Ingman, L.P.; Punkkinen, M.; Ylinen, E.E. [Wihuri Physical Lab., Turku Univ., Turku (Finland)

    1995-12-31

    The interpretation of NMR spectra for polycrystalline sample of ammonium perchlorate in helium temperature assumes the tunneling of NH{sub 4}{sup +}. Such interpretation does not agree with experimental data. The hypothesis of additional motion (fast rotation around one of C3 axis) has been checked and discussed on the base of NMR spectra of NH{sub 4}ClO{sub 4} monocrystal for the temperature range 2.1-25 K. 9 refs, 1 fig.

  3. Specific interactions of functionalised gold surfaces with ammonium perchlorate or starch; towards a chemical cartography of their mixture

    Energy Technology Data Exchange (ETDEWEB)

    Mercier, D. [CNRS, UMR CNRS 7609, Laboratoire de Reactivite de Surface, Paris (France); Universite Pierre et Marie Curie - UPMC Paris VI, Laboratoire de Reactivite de Surface, 4 place Jussieu, 75252 Paris Cedex 05 (France); Laboratoire de recherche conventionne CEA/UPMC n Degree-Sign 1, Paris (France); Mercader, C.; Quere, S.; Hairault, L. [CEA, DAM, Le Ripault, F-37260 Monts (France); Laboratoire de recherche conventionne CEA/UPMC n Degree-Sign 1, Paris (France); Methivier, C. [CNRS, UMR CNRS 7609, Laboratoire de Reactivite de Surface, Paris (France); Universite Pierre et Marie Curie - UPMC Paris VI, Laboratoire de Reactivite de Surface, 4 place Jussieu, 75252 Paris Cedex 05 (France); Laboratoire de recherche conventionne CEA/UPMC n Degree-Sign 1, Paris (France); Pradier, C.M., E-mail: claire-Marie.pradier@upmc.fr [CNRS, UMR CNRS 7609, Laboratoire de Reactivite de Surface, Paris (France); Universite Pierre et Marie Curie - UPMC Paris VI, Laboratoire de Reactivite de Surface, 4 place Jussieu, 75252 Paris Cedex 05 (France); Laboratoire de recherche conventionne CEA/UPMC n Degree-Sign 1, Paris (France)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer Measurements of interactions by Quartz Crystal Microbalance. Black-Right-Pointing-Pointer AFM and CFM measurements, tip functionalisation. Black-Right-Pointing-Pointer Surface nano-imaging. - Abstract: By functionalising gold samples, planar wafers or AFM tips, with an acid- or an amino acid-terminated thiols, mercaptoundecanoic acid (MUA) and homocystein (H-Cyst) respectively, we were able to differentiate the interactions with ammonium perchlorate (AP) and starch (S), two components of a nanocomposition mixture. To do so, the interaction between gold functionalized surfaces and the two targeted compounds have been characterized and quantified by several complementary techniques. Polarisation modulation-infrared spectroscopy (PM-IRRAS), and X-ray photoelectron spectroscopy (XPS), providing chemical analyses of gold surfaces after contacting S or AP, proved that both compounds were retained on MUA or H-Cyst-modified surfaces, but to various extents. Quartz crystal microbalance on-line measurements enabled to monitor the kinetics of interaction and showed distinct differences in the behaviour of MUA and H-Cyst-surfaces towards the two compounds. Having observed that only H-Cyst-modified surfaces enables to get a contrast on the chemical force microscopy (CFM) images, this new result could be well explained by examining the data obtained by combining the above-mentioned surface characterisation techniques.

  4. Specific interactions of functionalised gold surfaces with ammonium perchlorate or starch; towards a chemical cartography of their mixture

    Science.gov (United States)

    Mercier, D.; Mercader, C.; Quere, S.; Hairault, L.; Méthivier, C.; Pradier, C. M.

    2012-10-01

    By functionalising gold samples, planar wafers or AFM tips, with an acid- or an amino acid-terminated thiols, mercaptoundecanoic acid (MUA) and homocystein (H-Cyst) respectively, we were able to differentiate the interactions with ammonium perchlorate (AP) and starch (S), two components of a nanocomposition mixture. To do so, the interaction between gold functionalized surfaces and the two targeted compounds have been characterized and quantified by several complementary techniques. Polarisation modulation-infrared spectroscopy (PM-IRRAS), and X-ray photoelectron spectroscopy (XPS), providing chemical analyses of gold surfaces after contacting S or AP, proved that both compounds were retained on MUA or H-Cyst-modified surfaces, but to various extents. Quartz crystal microbalance on-line measurements enabled to monitor the kinetics of interaction and showed distinct differences in the behaviour of MUA and H-Cyst-surfaces towards the two compounds. Having observed that only H-Cyst-modified surfaces enables to get a contrast on the chemical force microscopy (CFM) images, this new result could be well explained by examining the data obtained by combining the above-mentioned surface characterisation techniques.

  5. Sol–gel method to prepare graphene/Fe{sub 2}O{sub 3} aerogel and its catalytic application for the thermal decomposition of ammonium perchlorate

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Yuanfei; Li, Xiaoyu; Li, Guoping; Luo, Yunjun, E-mail: yjluo@bit.edu.cn [Beijing Institute of Technology, School of Materials Science and Engineering (China)

    2015-10-15

    Graphene/Fe{sub 2}O{sub 3} (Gr/Fe{sub 2}O{sub 3}) aerogel was synthesized by a simple sol–gel method and supercritical carbon dioxide drying technique. In this study, the morphology and structure were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and nitrogen sorption tests. The catalytic performance of the as-synthesized Gr/Fe{sub 2}O{sub 3} aerogel on the thermal decomposition of ammonium perchlorate (AP) was investigated by thermogravimetric and differential scanning calorimeter. The experimental results showed that Fe{sub 2}O{sub 3} with particle sizes in the nanometer range was anchored on the Gr sheets and Gr/Fe{sub 2}O{sub 3} aerogel exhibits promising catalytic effects for the thermal decomposition of AP. The decomposition temperature of AP was obviously decreased and the total heat release increased as well.

  6. Preparation of CoFe2O4 Nano crystallites by Solvo thermal Process and Its Catalytic Activity on the Thermal Decomposition of Ammonium Perchlorate

    International Nuclear Information System (INIS)

    Nanometer cobalt ferrite (CoFe2O4) was synthesized by polyol-medium solvo thermal method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). Further, the catalytic activity and kinetic parameters of CoFe2O4 nano crystallites on the thermal decomposition behavior of ammonium perchlorate (AP) have been investigated by thermogravimetry and differential scanning calorimetry analysis (TG-DSC). The results imply that the catalytic performance of CoFe2O4 nano crystallites is significant and the decrease in the activation energy and the increase in the rate constant for AP further confirm the enhancement in catalytic activity of CoFe2O4 nano crystallites. A mechanism based on an proton transfer process has also been proposed for AP in the presence of CoFe2O4 nano crystallites.

  7. Synthesis and characterization of an energetic compound Cu(Mtta)2(NO3)2 and effect on thermal decomposition of ammonium perchlorate.

    Science.gov (United States)

    Yang, Qi; Chen, Sanping; Xie, Gang; Gao, Shengli

    2011-12-15

    An energetic coordination compound Cu(Mtta)(2)(NO(3))(2) has been synthesized by using 1-methyltetrazole (Mtta) as ligand and its structure has been characterized by X-ray single crystal diffraction. The central copper (II) cation was coordinated by four O atoms from two Mtta ligands and two N atoms from two NO(3)(-) anions to form a six-coordinated and distorted octahedral structure. 2D superamolecular layer structure was formed by the extensive intermolecular hydrogen bonds between Mtta ligands and NO(3)(-) anions. Thermal decomposition process of the compound was predicted based on DSC and TG-DTG analyses results. The kinetic parameters of the first exothermic process of the compound were studied by the Kissinger's and Ozawa-Doyle's methods. Sensitivity tests revealed that the compound was insensitive to mechanical stimuli. In addition, compound was explored as additive to promote the thermal decomposition of ammonium perchlorate (AP) by differential scanning calorimetry.

  8. 纳米级金属和金属复合物粉末对高氯酸铵和高氯酸铵/聚合丁二烯复合固体推进剂热分解特性的影响%Effects of Metal and Composite Metal Nanopowders on the Thermal Decomposition of Ammonium Perchlorate (AP) and the Ammonium Perchlorate/Hydroxyterminated Polybutadiene (AP/HTPB) Composite Solid Propellant

    Institute of Scientific and Technical Information of China (English)

    刘磊力; 李凤生; 谈玲华; 李敏; 杨毅

    2004-01-01

    Effects of metal (Ni, Cu, Al) and composite metal (NiB, NiCu, NiCuB) nanopowders on the thermal decomposition of ammonium perchlorate (AP) and composite solid propellant ammonium perchlorate/hydroxyterminated polybutadiene (AP/HTPB) were studied by thermal analysis (DTA). The results show that metal and composite metal nanopowders all have good catalytic effects on the thermal decomposition of AP and AP/HTPB composite solid propellant. The effects of metal nanopowders on the thermal decomposition of AP are less than those of the composite metal nanopowders. The effects of metal and composite metal nanopowders on the thermal decomposition of AP are different from those on the thermal decomposition of the AP/HTPB composite solid propellant.

  9. Green synthesis of Co3O4 nanoparticles and their applications in thermal decomposition of ammonium perchlorate and dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Co3O4 NPs were synthesized from the leaves extract of plant Calotropis gigantea. • Green synthesis of Co3O4 NPs is a cost effective and eco-friendly route. • Faster thermal decomposition of AP occurred in presence of the green synthesized Co3O4 NPs. • A high burning rate of CSP was observed. • Green synthesized Co3O4 NPs displays the good electrocatalytic activity to reduction of I3− to I− ions. - Abstract: In this paper, we report on the green synthesis of cobalt oxide nanoparticles (Co3O4 NPs) using leaves extract of plant Calotropis gigantea and characterize by X-ray diffraction (XRD), UV–vis spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). The green synthesized Co3O4 NPs showed excellent catalytic effect on the thermal decomposition of ammonium perchlorate (AP) and burning rate of composite solid propellants (CSPs). Kinetics of slow and rapid thermal decomposition has been investigated by isoconversional and ignition delay methods, respectively. Moreover, the electrocatalytic performance of green synthesized Co3O4 NPs in dye-sensitized solar cells (DSSC) has also been evaluated. The cyclic voltametry measurement shows good electrocatalytic activity of Co3O4 NPs toward the reduction of I3− to I− ions

  10. Experimental study on processability of ammonium perchlorate/hydroxyl-terminated polybutadiene composite propellant (I). Influences of operating temperature on viscosity of uncured propellant

    Energy Technology Data Exchange (ETDEWEB)

    Koga, M.; Hagihara, Y. [National Defense Academy, Kanagawa (Japan)

    1998-01-01

    Ammonium perchlorate (AP)/hydroxyl-terminated polybutadiene (HTPB) composite propellant was adopted in this study, because AP/HTPB composite propellant is the most widely used one at present. In order to design the formulation of AP/HTPB composite propellant, it is necessary to spread the range of a specific impulse of AP/HTPB composite propellant widely, especially towards a high specific impulse region. Specific impulse of AP/HTPB composite propellant increases with an increasing AP content and when the AP content is about 90wt% the maximum specific impulse can be realized theoretically. Because an upper limit of AP content in propellant exists technically for the size distribution of AP used, the upper limit of specific impulse must be so. In order to increase the upper limit of specific impulse, it is necessary to increase the upper limit of AP content. In this study, the relationships between the viscosity of HTPB with a curing agent or uncured propellant and the curing time were investigated at temperatures from 313K to 353K, and was made to find out the optimum operating temperature for mixing and casting of uncured propellant experimentally. 4 refs., 5 figs.

  11. Green synthesis of Co{sub 3}O{sub 4} nanoparticles and their applications in thermal decomposition of ammonium perchlorate and dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, J.K. [Department of Chemistry, Deen Dayal Upadhyay Gorakhpur University, Gorakhpur (India); Srivastava, Pratibha, E-mail: author.pratibhas1980@gmail.com [Department of Chemistry, Deen Dayal Upadhyay Gorakhpur University, Gorakhpur (India); Singh, Gurdip [Department of Chemistry, Deen Dayal Upadhyay Gorakhpur University, Gorakhpur (India); Akhtar, M. Shaheer [New & Renewable Energy Material Development Center (NewREC), Chonbuk National University, Jeonbuk (Korea, Republic of); Ameen, S. [Energy Materials & Surface Science Laboratory, Solar Energy Research Center, School of Chemical Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2015-03-15

    Graphical abstract: - Highlights: • Co{sub 3}O{sub 4} NPs were synthesized from the leaves extract of plant Calotropis gigantea. • Green synthesis of Co{sub 3}O{sub 4} NPs is a cost effective and eco-friendly route. • Faster thermal decomposition of AP occurred in presence of the green synthesized Co{sub 3}O{sub 4} NPs. • A high burning rate of CSP was observed. • Green synthesized Co{sub 3}O{sub 4} NPs displays the good electrocatalytic activity to reduction of I{sub 3}{sup −} to I{sup −} ions. - Abstract: In this paper, we report on the green synthesis of cobalt oxide nanoparticles (Co{sub 3}O{sub 4} NPs) using leaves extract of plant Calotropis gigantea and characterize by X-ray diffraction (XRD), UV–vis spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). The green synthesized Co{sub 3}O{sub 4} NPs showed excellent catalytic effect on the thermal decomposition of ammonium perchlorate (AP) and burning rate of composite solid propellants (CSPs). Kinetics of slow and rapid thermal decomposition has been investigated by isoconversional and ignition delay methods, respectively. Moreover, the electrocatalytic performance of green synthesized Co{sub 3}O{sub 4} NPs in dye-sensitized solar cells (DSSC) has also been evaluated. The cyclic voltametry measurement shows good electrocatalytic activity of Co{sub 3}O{sub 4} NPs toward the reduction of I{sub 3}{sup −} to I{sup −} ions.

  12. PERCHLORATE FACTS

    Science.gov (United States)

    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,...

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

    NARCIS (Netherlands)

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

    2011-01-01

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

  14. Study on mechanism of thyroid cytotoxicity of ammonium perchlorate%过氯酸铵对甲状腺细胞毒作用机制的研究

    Institute of Scientific and Technical Information of China (English)

    刘琴; 丁淼鸿; 张娆; 陈红霞; 周星星; 徐慧芳; 陈卉; 彭开良

    2013-01-01

    目的 探讨过氯酸铵(AP)对甲状腺细胞的毒作用机制.方法 将甲状腺体外细胞培养到一定阶段,分别给予AP浓度为0、5、10、20、40、60 mmol/L的培养液进行细胞染毒,收集培养的细胞和上清液做以下指标测定.用噻唑蓝比色法(MTT法)测定细胞增殖,用流式细胞技术检测法测定细胞凋亡,用酶联免疫吸附试验(ELISA)测定甲状腺球蛋白(Tg)浓度,用比色法测定乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)、丙二醛(MDA)等指标.结果 60 mmol/L AP染毒组细胞12、24、48、72 h时,存活率分别为74.93%、42.26%、2.66%和0.99%,40 mmol/L AP染毒组细胞24、48、72 h时,细胞存活率分别为73.15%、30.91%和3.03%,与对照组(100%)比较,差异均有统计学意义(P<0.05或P<0.01).各染毒组细胞总凋亡率均较对照组明显增加,20、40、60 mmol/L剂量组细胞早期凋亡率分别为15.70%、15.84%和16.96%,较对照组(9.54%)明显增加(P<0.05或P<0.01);60 mmol/L剂量组细胞晚期凋亡率为16.54%,较对照组(6.11%)明显增加,差异均有统计学意义(P<0.05或P<0.01).40 mmol/L染毒组细胞LDH活力为0.70 U/ml,较对照组(0.55 U/ml)明显升高,差异有统计学意义(P<0.01);5mmol/L染毒组细胞MDA含量为1.08 mmol/L,较对照组(2.36 mmol/L)降低,差异亦有统计学意义(P<0.05).结论 AP作用于甲状腺细胞,可明显改变细胞形态,降低细胞存活率,这可能与AP抑制甲状腺细胞增殖,诱导甲状腺细胞凋亡,破坏甲状腺细胞膜完整性有关.AP对甲状腺细胞氧化损伤并不明显.%Objective To investigate the mechanism of thyroid cytotoxicity mechanism of ammonium perchlorate (AP).Methods Thyroid cells were cultured in vitro to a certain stage and then exposed to AP (0,5,10,20,40,and 60 mmol/L) in culture solution; the cultured cells and supernatant were collected.Cell viability was measured by MTT assay; cell apoptosis was determined by flow

  15. Radioactive Iodide (131I Excretion Profiles in Response to Potassium Iodide (KI and Ammonium Perchlorate (NH4ClO4 Prophylaxis

    Directory of Open Access Journals (Sweden)

    Jeffrey Fisher

    2012-08-01

    Full Text Available Radioactive iodide (131I protection studies have focused primarily on the thyroid gland and disturbances in the hypothalamic-pituitary-thyroid axis. The objective of the current study was to establish 131I urinary excretion profiles for saline, and the thyroid protectants, potassium iodide (KI and ammonium perchlorate over a 75 hour time-course. Rats were administered 131I and 3 hours later dosed with either saline, 30 mg/kg of NH4ClO4 or 30 mg/kg of KI. Urinalysis of the first 36 hours of the time-course revealed that NH4ClO4 treated animals excreted significantly more 131I compared with KI and saline treatments. A second study followed the same protocol, but thyroxine (T4 was administered daily over a 3 day period. During the first 6–12 hour after 131I dosing, rats administered NH4ClO4 excreted significantly more 131I than the other treatment groups. T4 treatment resulted in increased retention of radioiodide in the thyroid gland 75 hour after 131I administration. We speculate that the T4 treatment related reduction in serum TSH caused a decrease synthesis and secretion of thyroid hormones resulting in greater residual radioiodide in the thyroid gland. Our findings suggest that ammonium perchlorate treatment accelerates the elimination rate of radioiodide within the first 24 to 36 hours and thus may be more effective at reducing harmful exposure to 131I compared to KI treatment for repeated dosing situations. Repeated dosing studies are needed to compare the effectiveness of these treatments to reduce the radioactive iodide burden of the thyroid gland.

  16. Effects of various lron oxides on burning rate of ammonium perchlorate/hydroxyl-terminated polybutadiene composite propellants. Part 1. AP/HTPB kei composite suishin'yaku no nensho sokudo ni oyobosu kakushu sankatetsu no koka. (1)

    Energy Technology Data Exchange (ETDEWEB)

    Hagihara, Y.; Ichikawa, T.; Suzuki, M.; Koga, M. (The National Defense Academy, Yokosuka (Japan))

    1991-12-31

    Effect of iron oxide catalysts on burning rate of ammonium perchlorate(AP)/hydroxyl-terminated polybutadine(HTPB) composite propellants with AP 80 % and HTPB 20 % by weight was studied combining 7 various particle sizes of iron oxide measured with scanning electron microscope within the pressure range of 0.4 MPa - 8 MPa. Burning rate has increased with the decrease of particle diameter and this decrement is in the order with the diameter 0.36{mu}m, 0.30{mu}m, 0.26{mu}m, 0.20{mu}m, 0.16{mu}m, 0.14{mu}m. Smaller the particle size the larger is the surface area and this results in the increase in the contact surface area. As a result it has been concluded that with the decrease of average diameter the burning rate is increased. Pressure exponent without catalyst is 0.46 and with catalyst it is 0.45-0.49. This has meant that catalyst does not effect pressure exponent. 3 refs., 4 figs., 3 tabs.

  17. PERCHLORATE UPTAKE AND TRANSFORMATION IN AQUATIC PLANTS

    Science.gov (United States)

    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...

  18. Perchlorate isotope forensics

    Science.gov (United States)

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

    2005-01-01

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

  19. Perchlorate in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Martinelango, P. Kalyani [Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409-1061 (United States); Tian Kang [Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX 79409 (United States); Dasgupta, Purnendu K. [Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409-1061 (United States)]. E-mail: Sandyd@ttu.edu

    2006-05-10

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

  20. Bioremediation Potential of Perchlorate Contaminated Deep Vadose Zone

    Science.gov (United States)

    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

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

    Science.gov (United States)

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

    2004-01-01

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

  2. Bioelectrical Perchlorate Remediation

    Science.gov (United States)

    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

  3. Effects of various iron oxides on burning rate of ammonium perchlorate/hydroxyl-terminated polybutadiene composite propellants. (II). ; Effect of grinding. AP/HTPB kei suishin prime yaku no nensho sokudo ni oyobosu kakushu sankatetsu no koka. 2. ; Funsai no koka

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, Y.; Ichikawa, T.; Suzuki, M.; Koga, M. (The National Defance Academy, Kanagawa (Japan))

    1992-06-30

    The previous report has explained that in ammonium perchlorate/hydroxyl -terminated polybutadiene composite propellants the smaller the average iron oxide grain size, the greater the combustion rate increasing effect. To investigate effects of micronization more precisely, this paper investigated a method to reduce the grain size, in which iron oxides are ground using a ball mill and explosive shock treatments, to study the effects on the combustion rate of iron oxides thus proud and treated. Preliminary experiments determined the optimal grinding conditions and the optical explosion shock conditions for either process, and X-ray diffraction analyses were carried out on iron oxide powders before and after the treatments. As a result of the grinding and treating experiments, it was found out that the smaller the iron oxide grain size, the greater the combustion rate increasing effect. In addition, if iron ozide powder with nearly uniform diameter is used, the iron oxide treated with the explosion shock showed greater effect of increasing the combustion rate than the one ground using a ball mill. 5 refs., 5 figs., 1 tab.

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

    International Nuclear Information System (INIS)

    Highlights: → Ammonium perchlorate, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and 2,4-dinitroanisole (DNAN) are the major constituents of PAX-21. → DNAN is identified as the primary toxicant responsible for inhibiting the activity of perchlorate reducing bacteria. → Iron treatment not only removes energetic compounds but also eliminates the toxic constituents that inhibit the subsequent microbial process. - Abstract: US Army and the Department of Defense (DoD) facilities generate perchlorate (ClO4-) 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

  5. 纳米SiO2负载的过渡金属硼化物对AP热分解的催化作用%Catalytic Activity of Nano-silica Supported Transition-metal Borides on the Thermal Decomposition of Ammonium Perchlorate

    Institute of Scientific and Technical Information of China (English)

    李茸; 刘祥萱; 王煊军

    2012-01-01

    采用化学还原法制备纳米NiB/SiO2、CoB/SiO2、MoB/SiO2催化剂,通过热重-差热分析(TG-DTA)研究了其对AP热分解过程的催化作用.结果表明,负载过渡金属硼化物催化剂对AP分解的催化活性顺序为:CoB/SiO2>NiB/SiO2> MoB/SiO2;加入质量分数5%的CoB/SiO2使AP高温热分解峰温度降低166.2℃;SiO2载体将CoB晶型转化推迟了 110℃左右,改善了催化剂的热稳定性.%The nano-silica supported transition metal catalysts NiB/SiO2 , CoB/SiO2 , MoB/SiO2 were prepared by chemical reduction method. Their catalytic activity on the thermal decomposition of ammonium perchlorate (AP) was studied by TG-DTA. Results show that catalytic activity of nano-silica supported transition metal borides for the thermal decomposition of AP decreases in the order: CoB/SiO2 > NiB/SiO2 >MoB/SiO2. The CoB/SiO2 (mass ration of 5%) catalyst makes the high-temperature thermal decomposition temperature of AP decrease by 166. 2℃. The SiO2 carrier makes the crystal transformation temperature delay about 110℃, revealling the improvement of thermal stability of the catalyst.

  6. 超临界水氧化工艺降低高氯酸铵废水中氨氮浓度的试验%Experiment of Reduction of Ammonia-Nitrogen Concentration in Wastewater Containing Ammonium Perchlorate (AP)by Supercritical Water Oxidation (SCWO)Process

    Institute of Scientific and Technical Information of China (English)

    黄婷; 楚华; 王国娟

    2014-01-01

    通过建立超临界水氧化试验装置,采用超临界技术对固体推进剂生产废水进行处理,研究了含高氯酸铵废水NH3N去除率与氧气流量、废水流量、反应釜温度和压力的关系。结果表明最佳的超临界水氧化条件:温度为390~410℃、压力为22MPa、控制氧气流量为0.6~1.0L/min、废水流量为2L/h,NH3N去除率可达99%,处理后NH3N浓度低于3mg/L,达到了国家排放标准。%The supercritical water oxidation device and the supercritical technology was used to treat solid propellant production wastewater. The relationship among oxygen flow,waste water flow,temperature,pressure of reactor and the removal efficiency of NH3 N in ammonium perchlorate wastewater was investigated. The results show that the optimal conditions of the supercritical water oxidation are as follows:temperature is 390~410℃,pressure is 22 MPa,oxygen flow is 0. 6~1. 0 L/min and wastewater flow is 2 L/h. Under such condition,removal efficiency of NH3 N can reach 99%,NH3 N concentration of treated waste water is less than 3 mg/L, which meet national standards.

  7. 2-(Benzenesulfonamidopyridinium perchlorate

    Directory of Open Access Journals (Sweden)

    Xun Li

    2009-06-01

    Full Text Available In the title compound, C11H11N2O2S+·ClO4−, the dihedral angle between the benzene and pyridinium rings is 87.33 (10°. An intramolecular N—H...O interaction, with an S=O-bonded O atom as receptor, occurs in the cation. In the crystal structure, ion pairs occur, being linked by strong N—H...O hydrogen bonds. The perchlorate anion plays a further role in the molecular packing by accepting several weak C—H...O interactions.

  8. Preparation of graphite-like carbon nitride and its catalytic performance for thermal decomposition of ammonium perchlorate%类石墨型氮化碳的制备及其对AP热分解催化性能研究∗

    Institute of Scientific and Technical Information of China (English)

    谈玲华; 杭祖圣; 寇波; 徐建华; 郏永强; 王善斌

    2015-01-01

    The g-C3 N4 was synthesized melamine used as precursor via semi-closed method.The structure and morphology of g-C3 N4 were characterized by means of X-ray diffraction(XRD),transmission electron microsco-py(SEM)and Fourier transform infrared spectroscopy(FT-IR).The catalysis of g-C3 N4 on thermal decomposi-tion of ammonium perchlorate(AP)was investigated bythermal gravimetric analysis (TG)and differential ther-mal analysis (DTA).The results show that the g-C3 N4 has layered structure.The g-C3 N4 make the two decom-position peaks of AP combine and the high-temperature decomposition peak value of AP decrease by 73.8 ℃, which exhibits good catalytic performance.The g-C3 N4 has excellent conductive properties and can accelerate the electron transfer in the process of oxidation-reduction cycle to make the decomposition of AP at a much lower temperature.%以三聚氰胺为前驱体、半封闭法制备出类石墨型氮化碳(g-C3 N4),采用 X 射线衍射(XRD)、扫描电子显微镜(SEM)、傅里叶红外光谱(FT-IR)对其结构和形貌进行表征,利用热失重(TG )、差热分析(DTA)研究g-C3 N4对高氯酸铵(AP)热分解的影响.结果表明,制备出的 g-C3 N4为层状结构. g-C3 N4对AP有较强的催化效果,可使 AP 的高低温分解峰合并,高温分解温度下降73.8℃.g-C3 N4优异的导电性能,在氧化还原循环中能加速电子转移,使 AP 在更低的温度下分解.

  9. Ferrocene Covalently Functionalized Graphene Oxide: Preparation,Characterization and Catalytic Performance for Thermal Decomposition of Ammonium Perchlorate%二茂铁功能化石墨烯氧化物的制备、表征及对高氯酸铵热分解的催化性能

    Institute of Scientific and Technical Information of China (English)

    周磊; 王立; 俞豪杰; 高敬民; 丁文兵; 高浩其

    2013-01-01

    A new ferrocene modified graphene oxide nano-material (GO-EDA-Fc) was synthesized via a new synthesis route.The GO-EDA-Fc was characterized by Fourier transform infrared spectra,and its morphology was observed under scanning electron microscopy.The graphene oxide was covalently decorated by ferrocene.The catalytic performance of GO-EDA-Fc in the thermal decomposition of ammonium perchlorate(AP) was investigated by thermogravimetric analysis (TGA).The results showed that GO-EDA-Fc exhibited high catalytic activity.When 4wt% of GO-EDA-Fc was added,the peak temperature of the high-temperature decomposition peak of AP had a decrease of 60℃ and the peak of the low-temperature decomposition was shifted to lower as well.The more GO-EDA-Fc was added,the better catalytic performance would be achieved.Notably,the ferrocene functionalized graphenc oxide had shown a synergistic catalytic effect.The mechanism of promote action was also investigated.%本文通过一种新的合成路线合成了二茂铁功能化的氧化石墨烯(GO-EDA-Fc).利用傅里叶变换红外光谱和扫描电子显微镜对其结构和形貌进行了表征.通过热重分析(TGA)研究了其对高氯酸铵(AP)热分解的催化性能,结果表明,氧化石墨烯和二茂铁表现出很好的协同催化效果,对AP热分解具有高的催化活性.催化效果随着GO-EDA-Fc加入量的增加而增强,当加入4wt%的GO-EDA-Fc时,AP的高温分解峰的峰值温度下降了60℃,低温分解峰的峰值也有降低.文中还对催化机制进行了研究.

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

    KAUST Repository

    Chen, Dennis P.

    2012-10-02

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

  11. Perchlorate Reduction by Yeast for Mars Exploration

    Science.gov (United States)

    Sharma, Alaisha

    2015-01-01

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

  12. PERCHLORATE CROP INTERACTIONS VIA CONTAMINATED IRRIGATION WATER

    Science.gov (United States)

    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...

  13. Hydrothermal oxidation of organic wastes using reclaimed ammonium nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Proesmans, P.I.; Luan, L.; Buelow, S.J.

    1996-04-01

    Ammonium nitrate is being studied as an alternative for ammonium perchlorate as an oxidizing agent in Department of Defense 1.1 and 1.3 rocket propellants. Use of ammonium nitrate would eliminate the HCl produced by ammonium perchlorate upon thermal decomposition. To stabilize the ammonium nitrate, which suffers from phase instability, potassium dinitramide (KDN) is added. This increased use of ammonium nitrate will ultimately create a need for environmentally responsible processes to reuse ammonium nitrate extracted from demilitarized rocket motors. Ammonium Nitrate was investigated as an oxidizing agent for methanol, acetic acid and phenol. High removal of organic, ammonia and nitrate was achieved at stoichiometric concentrations. The oxidation of ammonia by nitrate was much faster than the oxidation of either methanol or acetic acid. Phenol, however, was in strong competition with ammonia for the oxidizer (nitrate). Nitrogen products included N{sub 2}, N{sub 2}O, NO{sub 2{sup {minus}}} as well as toxic NO and trace amounts of NO{sub 2}. Carbon products were CO{sub 2}, HCO{sub 3{sup {minus}}}, CO{sub 3}{sup 2{minus}}, and CO.

  14. Combined effects of exposure to ammonium perchlorate and potassium iodide on apoptosis and oxidative stress in the human thyroid cells%过氯酸铵及碘化钾联合作用对人甲状腺细胞凋亡及氧化应激的影响

    Institute of Scientific and Technical Information of China (English)

    陈红霞; 赵明; 刘琴; 彭开良

    2015-01-01

    目的:研究过氯酸铵(AP)及碘化钾(KI)联合作用对人甲状腺细胞(nthy-ori3-1)氧化应激及诱导凋亡的影响。方法体外培养 nthy-ori3-1细胞,不同浓度 AP(0、5、10、20、40 mmol/L)及 KI (5 mmol/L)联合染毒后培养24 h,CCK8法检测 nthy-ori3-1细胞的增殖活力,流式细胞仪检测细胞凋亡率及细胞内活性氧(ROS)产生情况,同时测定氧化损伤指标丙二醛(MDA)、过氧化氢酶(CAT)活力。结果 AP 抑制nthy-ori3-1细胞增殖具有明显的剂量依赖性。与对照组比较,各组细胞内 ROS 生成量随着染毒剂量的增加出现降低趋势,除5 mmol/L AP 剂量组外,差异均有统计学意义(P 0.05)。结论 AP 和 KI 联合作用可致 nthy-ori3-1细胞出现氧化应激,且二者之间存在明显的剂量-反应关系,碘在一定程度上可缓解 AP 对甲状腺细胞的氧化应激反应。%Objective To explore the combined effects of ammonium perchlorate (AP)and potassium iodide(KI)on the oxidative stress and apoptosis in Nthy-ori3-1 thyroid cells.Methods The Nthy-ori3-1 cells cultured at 37 ℃,5% CO 2 in vitro,were exposed to different concentrations of AP (10,20,40 mmol/L)and KI(5,25 mmol/L)for 24 h,then the cell proliferation activity was detected by the CCK8 assay,while the apoptosis and intracellular generated reactive oxygen species (ROS)were measured by flow cytometry, simultaneously with the oxidative damage indicators malondialdehyde(MDA)and catalase(CAT)activity being detected.Results The significant dose-dependence relationship was found in the inhibition of Nthy-ori3-1 cell proliferation induced by AP.Compared with the control group,the ROS generation of the cells in each group appeared to decrease with dose increase except for the 5mmol/LAP dose group, and the differences were statistically significant(P 0.05).Conclusions AP might lead to oxidative stress on the Nthy-ori3-1 cell,as well as the significant dose-response relationship between the dose and effect

  15. Synthesis of 2,2-Diferrocenylpropane-based Tetrazole and Its Catalysis Performance for Thermal Decomposition of Ammonium Perchlorate%双核茂铁四氮唑的合成及对高氯酸铵热分解的催化作用

    Institute of Scientific and Technical Information of China (English)

    廖文向; 豆雅洁; 王静; 谢莉莉; 林芬; 袁耀锋

    2012-01-01

    moderate yield, and then compound 1 was transformed into 2,2-diferrocenylpropane carbaldehyde oxime(2) . Dehydration of the oxime gave 2,2-diferrocenylpropane nitrile(3). Finally, compound 4 was obtained via click reaction( [2+3] cycloaddi-tion) between compound 3 and sodium azide. Structures of the target compounds were characterized by H NMR,FTIR and mass spectrum. Electrochemical properties of the target compounds were investigated by cyclic voltammetry and differential pulse voltammetry. Relationship between electrochemical behavior of multi-component redox and structure was discussed. Thermal decomposition characteristics of ammonium perchlorate (AP) with 5% (mass fraction) of compound 3 or 4 were investigated by differential scanning calorimetry (DSC) and thermogravimetry ( TG) analysis. The results showed that the final exothermic peak temperature of AP was reduced by about 100 ℃ and compounds 3 and 4 had good combustion catalytic characteristics on AP.

  16. Organic carbon biostimulates rapid rhizodegradation of perchlorate.

    Science.gov (United States)

    Yifru, Dawit D; Nzengung, Valentine A

    2008-12-01

    Previous hydroponics and field studies identified phytodegradation and rhizodegradation as the two main mechanisms by which plants metabolize perchlorate. Plant uptake and phytodegradation of perchlorate is a slower and undesired process that poses ecological risks resulting from phytoaccumulation of some fraction of the perchlorate. Meanwhile, rhizodegradation is a more rapid and favored process involving perchlorate-degrading bacteria utilizing dissolved organic carbon (DOC) as a carbon and energy (electron) source to rapidly degrade perchlorate to innocuous chloride. In the present study, rhizodegradation of perchlorate by willow trees (Salix nigra) was biostimulated using electron sources obtained from natural and artificial carbon sources. In bioreactors provided with carbon sources as 500 mg/L DOC, 25 to 40 mg/L of initial perchlorate concentrations were removed to below the ion chromatography method detection limit of 2 microg/L in approximately 9 d. For planted controls provided with no electron donors, the time required for the complete removal of the same doses of perchlorate was up to 70 d. Enhancement of rhizodegradation by organic carbon reduced the phytoaccumulated fraction of perchlorate by an order of magnitude from approximately 430 to 20 mg/kg. The implication of the present study is that the high fraction uptake and phytoaccumulation of perchlorate in agricultural products and the recycling of perchlorate into the ecosystem can be significantly curtailed by supplying electron donors derived from organic carbon sources to the root zone of plants. PMID:18593217

  17. PERCHLORATE PHYTOREMEDIATION USING HARDWOOD TREES AND VASCULAR PLANTS

    Science.gov (United States)

    Perchlorate has contaminated water and soils at several locations in the United States. Perchlorate iswater 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...

  18. Aripiprazole salts. II. Aripiprazole perchlorate.

    Science.gov (United States)

    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.

  19. Kinetics for a membrane reactor reducing perchlorate.

    Science.gov (United States)

    Padhye, Lokesh; Rainwater, Ken; Jackson, W Andrew; Morse, Audra

    2007-02-01

    The major objectives of this work were to operate and construct an autohydrogenotrophic reactor and estimate perchlorate degradation kinetics. The results show that autohydrogenotrophic bacteria were cultured in the reactor and capable of removing 3.6 mg/d of perchlorate in the presence of excess hydrogen (99% removal). The reactor was successful in treating the average influent perchlorate concentration of 532 microg/L to the level of 3 microg/L. A first-order relationship was obtained between the concentration of active biomass in the reactor and the hydraulic retention time for the given amount of substrate. During the kinetic loading study, perchlorate removal ranged from 100 to 50%. The kinetic rate of perchlorate degradation observed in this study was 1.62 hr(-1). The significant degradation of perchlorate in these samples indicates the ubiquity of perchlorate-reducing organisms. Additionally, nitrate was simultaneously removed during water treatment (greater than 90% removal). Because of the excess levels of hydrogen, simultaneous removal of nitrate was not believed to significantly affect perchlorate removal. The area of concern was the lack of complete control over biological treatment. The growth of sulfate-reducing organisms in the reactor negatively affected perchlorate removal efficiency. There were no significant effects observed on the dissolved organic carbon and total suspended solids concentration of the effluent, suggesting that the treatment did not produce a large amount of biomass washout.

  20. 纳米结晶体Ni0.5Zn0.5Fe2O4对高氯酸铵热行为及分解反应动力学的影响%Effect of Nanocrystal Ni0.5Zn0.5Fe2O4 on Thermal Behavior and Decomposition Reaction Kinetics of Ammonium Perchlorate

    Institute of Scientific and Technical Information of China (English)

    仪建华; 赵凤起; 胡荣祖; Gurdip Singh

    2008-01-01

    采用差示扫描量热法(DSC)、热重和微分热重(TG-DTG)及固相原位反应池/快速扫描傅立叶变换红外联用技术(hyphenated in situ thermolysis/RSFTIR)研究了纳米结晶体Ni0.5Zn0.5Fe2O4与高氯酸铵(AP)组成的混合物的热行为和分解反应动力学.结果表明:Ni0.5Zn0.5Fe2O4使得AP的低、高温分解放热峰温分别提前17.44 K和27.74 K,并使得对应的分解热分别增加3.7 J·g-1和193.7 J·g-1.Ni0.5Zn0.5Fe2O4并不影响AP的晶转温度和晶转热.Ni0.5Zn0.5Fe2O4使得AP的TG曲线出现3个阶段,并使得后2个失重阶段的初始和终止温度都有所提前.凝聚相分解产物分析表明Ni0.5Zn0.5Fe2O4加速了凝聚相AP的分解及氨气的释放.含Ni0.5Zn0.5Fe2O4的AP的高温分解反应的动力学参数Ea=238.88 kJ·mol-1,A=1018.59 s-1,动力学方程可表示为dα/dt=1018.99(1-α)[-ln(1-α)]3/5e-2.87.始点温度(Te)和峰顶温度(Tp)计算得出AP的热爆炸临界温度值分别为:574.83 K和595.41 K.分解反应的活化熵(△S≠)、活化焓(△H≠)和活化能(△G≠)分别为:109.61 J·mol-1·K-1、236.49 kJ·mol-1及172.58 kJ·mol-1.%The thermal behavior and non-isothermal decomposition reaction kinetics of the mixture of the nanocrystal Ni0.5Zn0.5Fe2O4 and ammonium perchlorate (AP) were investigated by differential scanning calorimetry(DSC), thermogravimetry and differential thermogravimetry (TG-DTG), and the hyphenated technique of in situ thermolysis cell with rapid-scan Fourier transform infrared spectroscopy (in situ thermolysis/RSFTIR). The results show that Ni0.5Zn0.5Fe2O4 can decrease the low-temperature and the high-temperature exothermic peak temperatures of AP by 17.44 K and 27.74 K, respectively, and increase the decomposition heats of the two exothermic peaks by of AP. Ni0.5Zn0.5Fe2O4 makes AP shown three mass-loss processes, and it can decrease the initial and terminated temperatures of the last two mass-loss stages. The condensed phase decomposition product

  1. PHYTOREMEDIATION OF PERCHLORATE BY TOBACCO PLANTS

    Science.gov (United States)

    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,...

  2. ACCUMULATION AND FATE OF PERCHLORATE IN PLANTS

    Science.gov (United States)

    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...

  3. New synthetic method and properties of ammonium dinitramide; Ammonium dinitramide no shingoseiho to sono butsuri kagakuteki tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Hatano, H.; Onda, T.; Shiino, K. [Hosoya Kako Co. Ltd., Tokyo (Japan). Technology and Development Center; Miyazaki, S.; Matsuura, S. [Nissan Motor Co. Ltd., Saitama (Japan). Research and Development center

    1996-08-31

    Though, ammonium nitrate (AN) has been thought as solid propellant oxidizer, at present, ammonium perchlorate (AP) is mainly used because of the existence of crystal transition point, the improvement of propellant performance on AN and so forth. Ammonium dinitramide (ADN) can be used as an excellent oxidizer for high performance solid propellants, because it has much available oxygen. Furthermore, this propellant is smokeless, since ADN has no halogen resulting in generation of smoke on burning. ADN can be obtained by a new synthetic method which uses urea as starting substance and acquires nitrourea as intermediate product. According to this method, the yield is about 15% based on the amount of nitrourea. The hygroscopicity of this ADN is slightly higher than that of ammonium nitrate. Therefore, it is recommended to handle this substance at 50% of relative humidity or below. 13 refs., 7 figs., 4 tabs.

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

    Science.gov (United States)

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

    2000-01-01

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

  5. Perchlorate reduction by microbes inhabiting oil reservoirs

    Science.gov (United States)

    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

  6. The Microbiology of Perchlorate in the Environment

    Science.gov (United States)

    Coates, J. D.

    2007-12-01

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

  7. Perchlorate in The Great Lakes: Isotopic Composition and Origin

    OpenAIRE

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

    2014-01-01

    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....

  8. Kinetics of chlorite dismutase in a perchlorate degrading reactor sludge.

    Science.gov (United States)

    Nadaraja, Anupama Vijaya; Veetil, Prajeesh Gangadharan Puthiya; Vidyadharan, Athira; Bhaskaran, Krishnakumar

    2013-01-01

    Kinetics of chlorite dismutase (CD), the terminal enzyme involved in the perchlorate (ClO4(-)) reduction pathway, in a ClO4(-)-degrading bioreactor are reported in this study. Enzyme activity was determined from dissolved oxygen released during disproportionation of chlorite (ClO2(-)). CD activity was in the range 29.8-36.4 U/mg dry weight sludge, and kinetic constants Vmax and K(m) of the enzyme were 37.83 U/mg dry weight and 0.28 mM, respectively. Among reactor operational conditions, enzyme activity was observed at pH 4.0-9.0, with an optimum at pH 6.0. Redox potential in the range -50 to +120mV and NaCl up to 3.5 g/L had no significant effect on CD activity. However, co-occurring pollutants such as ammonium at 10 ppm, nitrite at 50 ppm and EDTA at 100 microM reduced CD activity substantially. The present study highlights ideal bioreactor conditions to avoid ClO2(-) toxicity, while indicating the buffering potential of a mixed microbial system against inhibiting factors to maintain stable CD activity in bioreactors.

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

    Science.gov (United States)

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

    2010-01-01

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

  10. Ammonium nitrate: a promising rocket propellant oxidizer

    Science.gov (United States)

    Oommen; Jain

    1999-06-30

    Ammonium nitrate (AN) is extensively used in the area of fertilizers and explosives. It is present as the major component in most industrial explosives. Its use as an oxidizer in the area of propellants, however, is not as extensive as in explosive compositions or gas generators. With the growing demand for environmental friendly chlorine free propellants, many attempts have been made of late to investigate oxidizers producing innocuous combustion products. AN, unlike the widely used ammonium perchlorate, produces completely ecofriendly smokeless products. Besides, it is one of the cheapest and easily available compounds. However, its use in large rocket motors is restricted due to some of its adverse characteristics like hygroscopicity, near room temperature phase transformation involving a volume change, and low burning rate (BR) and energetics. The review is an attempt to consolidate the information available on the various issues pertaining to its use as a solid propellant oxidizer. Detailed discussions on the aspects relating to phase modifications, decomposition chemistry, and BR and energetics of AN-based propellants, are presented. To make the review more comprehensive brief descriptions of the history, manufacture, safety, physical and chemical properties and various other applications of the salt are also included. Copyright 1999 Elsevier Science B.V.

  11. Elevated ammonium levels

    DEFF Research Database (Denmark)

    Søgaard, Rikke; Novak, Ivana; MacAulay, Nanna

    2012-01-01

    Increased ammonium (NH(4)(+)/NH(3)) in the brain is a significant factor in the pathophysiology of hepatic encephalopathy, which involves altered glutamatergic neurotransmission. In glial cell cultures and brain slices, glutamate uptake either decreases or increases following acute ammonium expos...

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

    Science.gov (United States)

    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. Extraction of Perchlorate Using Porous Organosilicate Materials

    Directory of Open Access Journals (Sweden)

    Jenna R. Taft

    2013-04-01

    Full Text Available 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.

  14. Different Strategies for Biological Remediation of Perchlorate Contaminated Groundwater

    OpenAIRE

    Wang, Yue

    2012-01-01

    Perchlorate (ClO4-) has gained attention recently due to its interference with thyroid gland function. In infants and unborn children, inadequate thyroid hormone production can cause mental retardation and thyroid tumors. Since new perchlorate standards will be proposed in 2013, and if a stricter standard is imposed, cost effective technologies will be in high demand. The overall objective of this research was to evaluate two perchlorate bioremediation strategies using indigenous soil bact...

  15. Anatase-brookite mixed phase nano TiO2 catalyzed homolytic decomposition of ammonium nitrate.

    Science.gov (United States)

    Vargeese, Anuj A; Muralidharan, Krishnamurthi

    2011-09-15

    Compared to the conventional ammonium perchlorate based solid rocket propellants, burning of ammonium nitrate (AN) based propellants produce environmentally innocuous combustion gases. Application of AN as propellant oxidizer is restricted due to low reactivity and low energetics besides its near room temperature polymorphic phase transition. In the present study, anatase-brookite mixed phase TiO(2) nanoparticles (~ 10 nm) are synthesized and used as catalyst to enhance the reactivity of the environmental friendly propellant oxidizer ammonium nitrate. The activation energy required for the decomposition reactions, computed by differential and non-linear integral isoconversional methods are used to establish the catalytic activity. Presumably, the removal of NH(3) and H(2)O, known inhibitors of ammonium nitrate decomposition reaction, due to the surface reactions on active surface of TiO(2) changes the decomposition pathway and thereby the reactivity.

  16. Atmospheric Production of Perchlorate on Earth and Mars

    Science.gov (United States)

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

    2009-12-01

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

  17. Evidence for the distribution of perchlorates on Mars

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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%. PMID:27449607

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

    Science.gov (United States)

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

    2014-10-01

    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. PMID:25171443

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

    Science.gov (United States)

    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...

  1. 76 FR 7762 - Drinking Water: Regulatory Determination on Perchlorate

    Science.gov (United States)

    2011-02-11

    ... Storage in the Thyroid Gland of Human Neonates. J. Pediatric Endocrinology & Metabolism. Vol. 16. p. 521... AGENCY 40 CFR Part 141 RIN 2040-AF08 Drinking Water: Regulatory Determination on Perchlorate AGENCY... the Agency's) regulatory determination for perchlorate in accordance with the Safe Drinking Water...

  2. PERCHLORATE IDENTIFICATION IN FERTILIZERS AND ACCUMULATION IN LETTUCE SEEDLINGS

    Science.gov (United States)

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

  3. AP的安全制备%Safe Preparations of Fine Ammonium Perchlorate Particles

    Institute of Scientific and Technical Information of China (English)

    Makoto Kohga

    2006-01-01

    Fine AP particles are required to manufacture the AP-based composite propellants with a wide burning rate range for various applications,especially high burning rate propellants. However,it is difficult to prepare a fine AP safely. Some safe methods for preparing the fine AP particles are reported such as the spray-dry method and freeze-dry method. It is shown that the crystal habit modified AP particle is an effective oxidizer to enhance the burning rate.

  4. Adamantane-1-ammonium acetate

    Directory of Open Access Journals (Sweden)

    Elise J. C. de Vries

    2011-06-01

    Full Text Available In the title compound, C10H18N+·C2H3O2−, the ammonium H atoms of the cation are linked to three acetate anions via N—H...O hydrogen bonds, forming a chain structure extending along the b axis.

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

    Science.gov (United States)

    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

  6. Perchlorates as Powerful Catalysts in Many Important Organic Transformations

    Institute of Scientific and Technical Information of China (English)

    G. Bartoli; L. Sambri; M. Locatelli

    2005-01-01

    @@ 1Introduction For long times, metallic perchlorates have been considered dangerous compounds[1] in that they function as explosives and as incontrollable oxidizers. Therefore, the fear of the great hazard connected with their manufacture and uses had prevented an extensive use both in research laboratories and in industrial processes[2].However, recently it has been cleared that this bad reputation is due to the mistaken association of metallic perchlorates with the oxidizing potential of perchloric acid and the pyrotechnic performances of NH4ClO4.

  7. The use of bis (-2-ethylhexyl) phosphoric acid for the extraction of zinc from concentrated ammonium chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Amer, S.; Luis, A.; Cuadra, A. de la; Caravaca, C.

    1994-01-01

    The extraction of zinc from concentrated ammonium chloride solutions by means of the bis(-2-ethylhexyl) phosphoric acid is studied. Mass balances and chemical equilibria relating the different chemical species in both phases are presented in order to establish a model describing the behaviour of the different species. Good agreement between experimental data and theoretical curves is obtained. A comparison of the zinc extraction from a strong complexing medium as that of concentrated ammonium chloride solutions with an uncomplexing zinc perchlorate solution is made, in order to see the influence of the complexing effect of the aqueous phase on zinc extraction. (Author) 36 p.

  8. High pressure studies of potassium perchlorate

    Science.gov (United States)

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

    2016-09-01

    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 → hν 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. We present the first direct evidence for O2 crystallization at higher pressures, demonstrating that O2 molecules aggregate at high pressure.

  9. The NAS Perchlorate Review: Adverse Effects?

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Science.gov (United States)

    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.

  11. Determination of Perchlorate in Bottled Water from Italy

    Directory of Open Access Journals (Sweden)

    Patrizia Iannece

    2013-06-01

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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  14. Oxidation of some disubstituted anisole derivatives with ceric perchlorate in perchloric acid solution

    International Nuclear Information System (INIS)

    The influence of concentration of particular reagents on the kinetics of Ce(IV) reduction by 2,6-dimethyl and 3,5-dimethyl-anisole as well as 2-methoxy-5-methyl- and 4-methoxy-2-methyl-aniline in perchloric acid solution was investigated, establishing the stoichiometry of these processes. Some intermediate products - macromolecular, derivatives of p-benzoquinone and 4,4'-diphenoquinone - were separated and identified. The effects of substituents and the conditions of performed oxidation processes on the kind and yields of the resultant products were considered. (author). 22 refs, 1 fig., 1 tab

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-03-15

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

  17. 高氯酸盐的环境毒理学效应及其机制的研究进展%Environmental toxicological effect and mechanism of perchlorate

    Institute of Scientific and Technical Information of China (English)

    吴春笃; 李顺; 许小红; 张波

    2013-01-01

    Perchlorate is a persistent toxic contaminant in the environment and the environmental problems caused have drawn the extensive attention of human beings. The perchlorate rarely exists in natural environment and mainly exists in the soil, furthermore, the atmosphere also produces a certain amount of perchlorate in some conditions. The pollution is mainly caused by the mass production and use of ammonium perchlorate and potassium perchlorate. Perchlorate is quite soluble,it can be rapidly transported and diffused in aqueous systems and achieve enrichment in plants and animals, then enters into human body through ingestion behavior. By competing with the sodium-iodide symporter (NIS) for transporting iodide into thyroid, perchlorate inhibits iodide uptake,influences the thyroid and pituitary hormone level and then inhibits the normal metabolism and growth of organisms. Based on the perchlorate toxicology data of potential adverse effects on thyroid function,growth, development,reproduction and neurodevelopment, this paper reviewed the perchlorate toxicity mechanism and the future research prospect was presented.%高氯酸盐是一种具有持久性的有毒污染物质,其环境污染问题引起了人类的广泛关注.天然环境中的高氯酸盐比例很少,主要存在于土壤中;此外,在某些环境条件下,大气中也能产生一定量的高氯酸盐;其人为污染主要来源于大量生产和使用的高氯酸铵和高氯酸钾.高氯酸盐易溶于水,可以在水环境中快速迁移扩散,在动植物体内富集并通过人类摄食作用进入人体.高氯酸根能够竞争性利用钠/碘转运体(NIS),抑制甲状腺吸收碘离子,进而影响甲状腺和脑垂体的激素水平,阻碍生物体正常的新陈代谢和生长发育.笔者基于高氯酸盐对甲状腺、生长发育、生殖行为及神经系统等潜在危害的毒理学研究,综述了高氯酸盐对生物体的毒性作用机制,并对其研究前景进行了展望.

  18. Aluminum-based drinking-water treatment residuals: A novel sorbent for perchlorate removal

    International Nuclear Information System (INIS)

    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 oC) 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. - Drinking-water treatment residuals are a low-cost sorbent for perchlorate

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

    Science.gov (United States)

    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...

  20. Ammonium diphosphitoindate(III

    Directory of Open Access Journals (Sweden)

    Farida Hamchaoui

    2013-04-01

    Full Text Available The crystal structure of the title compound, NH4[In(HPO32], is built up from InIII cations (site symmetry 3m. adopting an octahedral environment and two different phosphite anions (each with site symmetry 3m. exhibiting a triangular–pyramidal geometry. Each InO6 octahedron shares its six apices with hydrogen phosphite groups. Reciprocally, each HPO3 group shares all its O atoms with three different metal cations, leading to [In(HPO32]− layers which propagate in the ab plane. The ammonium cation likewise has site symmetry 3m.. In the structure, the cations are located between the [In(HPO32]− layers of the host framework. The sheets are held together by hydrogen bonds formed between the NH4+ cations and the O atoms of the framework.

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

    Science.gov (United States)

    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.

  2. Competitive microbial reduction of perchlorate and nitrate with a cathode directly serving as the electron donor

    International Nuclear Information System (INIS)

    Microbial reduction of perchlorate with an electrode as the electron donor represents an emerging technology for remediation of perchlorate contamination; it is important to know how perchlorate reduction behaves when nitrate, a co-contaminant of perchlorate is present. We reported that electrons derived from the electrode can be directly transferred to the bacteria with perchlorate or nitrate as the sole electron acceptor. The presence of nitrate, even at the 0.07 mM level, can slow reduction of perchlorate (0.70 mM) as a poised potential of -0.50 V (vs. SCE) was applied to the inoculated cathode. Increasing the concentration of nitrate resulted in a noticeable inhibitory effect on perchlorate reduction. When the nitrate concentration was 2.10 mM, reduction of 0.70 mM perchlorate was totally inhibited. Bacterial community analyses based on 16S rDNA gene analysis with denaturing gradient gel electrophoresis (DGGE) revealed that most of the bacteria newly enriched on the nitrate and/or perchlorate biocathodes were the known electrochemically active denitrifiers, which possibly prefer to reduce nitrate over perchlorate. These results show that nitrate is a more favorable electron acceptor than perchlorate in the bioelectrochemical system where the cathode directly serves as the electron donor

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

    Science.gov (United States)

    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.

  4. Structure of aqueous sodium perchlorate solutions.

    Science.gov (United States)

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

    2008-12-01

    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

  5. The Impact of Temperature on Anaerobic Biological Perchlorate Treatment

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

  7. Nitrate and Perchlorate removal from groundwater by ion exchange

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

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

  13. Solubility of the Sodium and Ammonium Salts of Oxalic Acid in Water with Ammonium Sulfate.

    Science.gov (United States)

    Buttke, Lukas G; Schueller, Justin R; Pearson, Christian S; Beyer, Keith D

    2016-08-18

    The solubility of the sodium and ammonium salts of oxalic acid in water with ammonium sulfate present has been studied using differential scanning calorimetry, X-ray crystallography, and infrared spectroscopy. The crystals that form from aqueous mixtures of ammonium sulfate/sodium hydrogen oxalate were determined to be sodium hydrogen oxalate monohydrate under low ammonium sulfate conditions and ammonium hydrogen oxalate hemihydrate under high ammonium sulfate conditions. Crystals from aqueous mixtures of ammonium sulfate/sodium oxalate were determined to be ammonium oxalate monohydrate under moderate to high ammonium sulfate concentrations and sodium oxalate under low ammonium sulfate concentrations. It was also found that ammonium sulfate enhances the solubility of the sodium oxalate salts (salting in effect) and decreases the solubility of the ammonium oxalate salts (salting out effect). In addition, a partial phase diagram for the ammonium hydrogen oxalate/water system was determined. PMID:27482644

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  16. 4-(2-Azaniumylethylpiperazin-1-ium bis(perchlorate

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Reisi

    2011-09-01

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

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

    International Nuclear Information System (INIS)

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

  18. Containerized Wetland Bioreactor Evaluated for Perchlorate and Nitrate Degradation

    Energy Technology Data Exchange (ETDEWEB)

    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

  19. Influence of the ammonium salt anion on the synergistic solvent extraction of lanthanides with mixtures of thenoyltrifluoroacetone and tridecylamine

    Energy Technology Data Exchange (ETDEWEB)

    Dukov, I.L.; Jordanov, V.M. [Univ. of Chemical Technology and Metallurgy, Sofia (Bulgaria). Dept. of Inorganic Chemistry

    1998-08-01

    The synergistic solvent extraction of Pr, Gd and Yb with mixtures of thenoyltrifluoroacetone (HTTA) and primary ammonium salt (tridecylammonium chloride or perchlorate, TDAH(Cl, ClO{sub 4})) in C{sub 6}H{sub 6} has been studied. The composition of the extracted species have been determined as Ln(TTA){sub 3}TDAHA(A{sup {minus}} = Cl{sup {minus}} or ClO{sub 4}{sup {minus}}). The values of the equilibrium constant K{sub T,S} have been calculated. The influence of the ammonium salt anion on the extraction process has been discussed. The separation factors of the pairs Gd/Pr and Yb/Gd have been determined.

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

    Science.gov (United States)

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

    2007-12-01

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

  1. Portable Amperometric Perchlorate Selective Sensors with Microhole Array-water/organic Gel Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hyuk; Girault, Hubert H.; Lee, Hye Jin [Kyungpook National Univ., Daegu (Korea, Republic of); Kim, Hyungi [Gyeongbuk Technopark, Gyeongsan (Korea, Republic of); Girault, Hubert H. [Ecole Polytechnique Federale de Lausanne, Lausanne (Switzerland)

    2013-09-15

    A novel stick-shaped portable sensing device featuring a microhole array interface between the polyvinylchloride-2-nitrophenyloctylether (PVC-NPOE) gel and water phase was developed for in-situ sensing of perchlorate ions in real water samples. Perchlorate sensitive sensing responses were obtained based on measuring the current changes with respect to the assisted transfer reaction of perchlorate ions by a perchlorate selective ligand namely, bis(dibenzoylmethanato)Ni(II) (Ni(DBM){sub 2}) across the polarized microhole array interface. Cyclic voltammetry was used to characterize the assisted transfer reaction of perchlorate ions by the Ni(DBM){sub 2} ligand when using the portable sensing device. The current response for the transfer of perchlorate anions by Ni(DBM){sub 2} across the micro-water/gel interface linearly increased as a function of the perchlorate ion concentration. The technique of differential pulse stripping voltammetry was also utilized to improve the sensitivity of the perchlorate anion detection down to 10 ppb. This was acquired by preconcentrating perchlorate anions in the gel layer by means of holding the ion transfer potential at 0 mV (vs. Ag/AgCl) for 30 s followed by stripping the complexed perchlorate ion with the ligand. The effect of various potential interfering anions on the perchlorate sensor was also investigated and showed an excellent selectivity over Br{sup -}, NO{sub 2}{sup -}, NO{sub 3}{sup -}, CO{sub 3}{sup 2-}, CH{sub 3}COO{sup -} and SO{sub 4}{sup 2-} ions. As a final demonstration, some regional water samples from the Sincheon river in Daegu city were analyzed and the data was verified with that of ion chromatography (IC) analysis from one of the Korean-certified water quality evaluation centers.

  2. Photodimerization and photooxygenation of 9-vinylcarbazole catalyzed by titanium dioxide and magnesium perchlorate

    Institute of Scientific and Technical Information of China (English)

    Hajime; Maeda; Mio; Yamamoto; Hideyuki; Nakagawa; Kazuhiko; Mizuno

    2010-01-01

    Photoreaction of 9-vinylcarbazole in acetonitrile in the presence of titanium dioxide and a catalytic amount of magnesium perchlorate gave 3,6-di(9-carbazolyl)-1,2-dioxane as a photooxygenated product via photodimerization of 9-vinylcarbazole.The photoreaction proceeds via an electron transfer mechanism,where magnesium perchlorate accelerated formation of the photo-oxygenated product.

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

    NARCIS (Netherlands)

    Liebensteiner, M.; Pinkse, M.W.H.; Schaap, P.J.; Stams, A.J.M.; Lomans, B.P.

    2013-01-01

    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 s

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

    Science.gov (United States)

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

    2014-01-01

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

  5. Perchlorate in groundwater: a synoptic survey of "pristine" sites in the coterminous United States.

    Science.gov (United States)

    Parker, David R; Seyfferth, Angelia L; Reese, Brandi Kiel

    2008-03-01

    Perchlorate is widely used as an oxidant in solid rocket propellants and energetic applications, and it has frequently been detected in groundwaters at concentrations relevant to human health. The possibility of naturally occurring perchlorate has only recently received significant attention. Relying primarily on domestic, agricultural, and recreational wells, we utilized a network of volunteers to help collect 326 groundwater samples from across the coterminous United States. Care was taken to avoid known, USEPA-documented sites of perchlorate use or release, as well as perchlorate contamination due to disinfection using hypochlorite. Using IC-ESI-MS and a Cl18O4- internal standard, we achieved a method detection limit (MDL) of 40 ng/L perchlorate and a minimum reporting level (MRL) of 120 ng/L. Of the 326 samples, 147 (45%) were below the MDL, while 42 (13%) were between the MDL and the MRL. Of the 137 samples that could be quantified, most (109) contained 10000 ng/L) previously reported for the west-central Texas area appear to be anomalous. Perchlorate concentrations were positively correlated with nitrate levels (P < 0.001) but not with chloride concentrations. Opportunities exist for follow-up studies of perchlorate's origins using isotope forensics and for further elucidation of the role of atmospheric processes in the formation or transport of perchlorate.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-30

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

  7. 21 CFR 582.1141 - Ammonium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  8. 77 FR 50613 - Didecyl Dimethyl Ammonium Carbonate and Didecyl Dimethyl Ammonium Bicarbonate; Exemption From the...

    Science.gov (United States)

    2012-08-22

    ... AGENCY 40 CFR Part 180 Didecyl Dimethyl Ammonium Carbonate and Didecyl Dimethyl Ammonium Bicarbonate... Didecyl Dimethyl Ammonium Carbonate and Didecyl Dimethyl Ammonium Bicarbonate, jointly referred to as.... Background and Statutory Findings In the Federal Register of December 8, 2011 (76 FR 76674) (FRL-...

  9. (Dicyanamido)[tris(2-pyridylmethyl)amine]zinc(II) perchlorate

    OpenAIRE

    Shi Guo Zhang; Hong Yan Zhao; Hong Li

    2008-01-01

    In the title complex, [Zn(C2N3)(C18H18N4)]ClO4, the ZnII ion has a slightly distorted trigonal–bipyramidal ZnN5 coordination geometry. The crystal structure is stabilized by weak intermolecular C—H...O and C—H...N hydrogen bonds. In addition, there are relatively close contacts between the O atoms of the perchlorate anion and symmetry-related pyridine rings [O...Cg = 3.179 (3) and 3.236 (3) Å, where Cg is the centroid of a pyridine ring], and between t...

  10. Phase diagram of ammonium nitrate

    Science.gov (United States)

    Dunuwille, M.; Yoo, C. S.

    2014-05-01

    Ammonium Nitrate (AN) has often subjected to uses in improvised explosive devices, due to its wide availability as a fertilizer and its capability of becoming explosive with slight additions of organic and inorganic compounds. Yet, the origin of enhanced energetic properties of impure AN (or AN mixtures) is neither chemically unique nor well understood -resulting in rather catastrophic disasters in the past1 and thereby a significant burden on safety in using ammonium nitrates even today. To remedy this situation, we have carried out an extensive study to investigate the phase stability of AN at high pressure and temperature, using diamond anvil cells and micro-Raman spectroscopy. The present results confirm the recently proposed phase IV-to-IV' transition above 17 GPa2 and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400 °C.

  11. Phase diagram of ammonium nitrate

    International Nuclear Information System (INIS)

    Ammonium Nitrate (AN) has often subjected to uses in improvised explosive devices, due to its wide availability as a fertilizer and its capability of becoming explosive with slight additions of organic and inorganic compounds. Yet, the origin of enhanced energetic properties of impure AN (or AN mixtures) is neither chemically unique nor well understood -resulting in rather catastrophic disasters in the past1 and thereby a significant burden on safety in using ammonium nitrates even today. To remedy this situation, we have carried out an extensive study to investigate the phase stability of AN at high pressure and temperature, using diamond anvil cells and micro-Raman spectroscopy. The present results confirm the recently proposed phase IV-to-IV' transition above 17 GPa2 and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400 °C.

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

    Science.gov (United States)

    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

  13. Palladium(II)-catalyzed oxidation of L-tryptophan by hexacyanoferrate(III) in perchloric acid medium: a kinetic and mechanistic approach

    Indian Academy of Sciences (India)

    Ahmed Fawzy

    2016-02-01

    The catalytic effect of palladium(II) on the oxidation of L-tryptophan by potassium hexacyanoferrate( III) has been investigated spectrophotometrically in aqueous perchloric acid medium. A first order dependence in [hexacyanoferrate(III)] and fractional-first order dependences in both [L-tryptophan] and [palladium(II)] were obtained. The reaction exhibits fractional-second order kinetics with respect to [H+]. Reaction rate increased with increase in ionic strength and dielectric constant of the medium. The effect of temperature on the reaction rate has also been studied and activation parameters have been evaluated and discussed. Initial addition of the reaction product, hexacyanoferrate(II), does not affect the rate significantly. A plausible mechanistic scheme explaining all the observed kinetic results has been proposed. The final oxidation products are identified as indole-3-acetaldehyde, ammonium ion and carbon dioxide. The rate law associated with the reaction mechanism is derived.

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

    Directory of Open Access Journals (Sweden)

    Ashraf Javidi

    2015-01-01

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

  15. High pressure structural, elastic and vibrational properties of green energetic oxidizer ammonium dinitramide

    Science.gov (United States)

    Yedukondalu, N.; Ghule, Vikas D.; Vaitheeswaran, G.

    2016-08-01

    Ammonium DiNitramide (ADN) is one of the most promising green energetic oxidizers for future rocket propellant formulations. In the present work, we report a detailed theoretical study on structural, elastic, and vibrational properties of the emerging oxidizer under hydrostatic compression using various dispersion correction methods to capture weak intermolecular (van der Waals and hydrogen bonding) interactions. The calculated ground state lattice parameters, axial compressibilities, and equation of state are in good accord with the available experimental results. Strength of intermolecular interactions has been correlated using the calculated compressibility curves and elastic moduli. Apart from this, we also observe discontinuities in the structural parameters and elastic constants as a function of pressure. Pictorial representation and quantification of intermolecular interactions are described by the 3D Hirshfeld surfaces and 2D finger print maps. In addition, the computed infra-red (IR) spectra at ambient pressure reveal that ADN is found to have more hygroscopic nature over Ammonium Perchlorate (AP) due to the presence of strong hydrogen bonding. Pressure dependent IR spectra show blue- and red-shift of bending and stretching frequencies which leads to weakening and strengthening of the hydrogen bonding below and above 5 GPa, respectively. The abrupt changes in the calculated structural, mechanical, and IR spectra suggest that ADN might undergo a first order structural transformation to a high pressure phase around 5-6 GPa. From the predicted detonation properties, ADN is found to have high and low performance characteristics (DCJ = 8.09 km/s and PCJ = 25.54 GPa) when compared with ammonium based energetic oxidizers (DCJ = 6.50 km/s and PCJ = 17.64 GPa for AP, DCJ = 7.28 km/s and PCJ = 18.71 GPa for ammonium nitrate) and well-known secondary explosives for which DCJ = ˜8-10 km/s and PCJ = ˜30-50 GPa, respectively.

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

    Science.gov (United States)

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

    2016-01-01

    Perchlorate is a common aquatic contaminant that has long been known to affect thyroid function in vertebrates, including humans. More recently perchlorate has been shown to affect primordial sexual differentiation in the aquatic model fishes zebrafish and threespine stickleback, but the mechanism has been unclear. Stickleback exposed to perchlorate from fertilization have increased androgen levels in the embryo and disrupted reproductive morphologies as adults, suggesting that perchlorate could disrupt the earliest stages of primordial sexual differentiation when primordial germ cells (PGCs) begin to form the gonad. Female stickleback have three to four times the number of PGCs as males during the first weeks of development. We hypothesized that perchlorate exposure affects primordial sexual differentiation by reducing the number of germ cells in the gonad during an important window of stickleback sex determination at 14-18 days post fertilization (dpf). We tested this hypothesis by quantifying the number of PGCs at 16 dpf in control and 100 mg/L perchlorate-treated male and female stickleback. Perchlorate exposure from the time of fertilization resulted in significantly reduced PGC number only in genotypic females, suggesting that the masculinizing effects of perchlorate observed in adult stickleback may result from early changes to the number of PGCs at a time critical for sex determination. To our knowledge, this is the first evidence of a connection between an endocrine disruptor and reduction in PGC number prior to the first meiosis during sex determination. These findings suggest that a mode of action of perchlorate on adult reproductive phenotypes in vertebrates, including humans, such as altered fecundity and sex reversal or intersex gonads, may stem from early changes to germ cell development. PMID:27383240

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

    Science.gov (United States)

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

    2016-01-01

    Perchlorate is a common aquatic contaminant that has long been known to affect thyroid function in vertebrates, including humans. More recently perchlorate has been shown to affect primordial sexual differentiation in the aquatic model fishes zebrafish and threespine stickleback, but the mechanism has been unclear. Stickleback exposed to perchlorate from fertilization have increased androgen levels in the embryo and disrupted reproductive morphologies as adults, suggesting that perchlorate could disrupt the earliest stages of primordial sexual differentiation when primordial germ cells (PGCs) begin to form the gonad. Female stickleback have three to four times the number of PGCs as males during the first weeks of development. We hypothesized that perchlorate exposure affects primordial sexual differentiation by reducing the number of germ cells in the gonad during an important window of stickleback sex determination at 14–18 days post fertilization (dpf). We tested this hypothesis by quantifying the number of PGCs at 16 dpf in control and 100 mg/L perchlorate-treated male and female stickleback. Perchlorate exposure from the time of fertilization resulted in significantly reduced PGC number only in genotypic females, suggesting that the masculinizing effects of perchlorate observed in adult stickleback may result from early changes to the number of PGCs at a time critical for sex determination. To our knowledge, this is the first evidence of a connection between an endocrine disruptor and reduction in PGC number prior to the first meiosis during sex determination. These findings suggest that a mode of action of perchlorate on adult reproductive phenotypes in vertebrates, including humans, such as altered fecundity and sex reversal or intersex gonads, may stem from early changes to germ cell development. PMID:27383240

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

    Directory of Open Access Journals (Sweden)

    Ann M Petersen

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

  19. Quaternary Ammonium Polyethyleneimine: Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    Ira Yudovin-Farber

    2010-01-01

    Full Text Available Quaternary ammonium polyethyleneimine- (QA-PEI- based nanoparticles were synthesized using two synthetic methods, reductive amination and N-alkylation. According to the first method, QA-PEI nanoparticles were synthesized by cross-linking with glutaraldehyde followed by reductive amination with octanal and further N-methylation with methyl iodide. The second method is based on crosslinking with dialkyl halide followed by N-alkylation with octyl halide and further N-methylation with methyl iodide. QA-PEI nanoparticles completely inhibited bacterial growth (>106 bacteria, including both Gram-positive, that is, Staphylococcus aureus at 80 g/mL, and Gram-negative, that is, Escherichia coli at 320 g/mL. Activity analysis revealed that the degree of alkylation and N-methylation of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl alkylated QA-PEI alkylated at 1 : 1 mole ratio (primary amine of PEI monomer units/alkylating agent. Also, cytotoxicity studies on MAT-LyLu and MBT cell lines were performed with QA-PEI nanoparticles. These findings confirm previous reports that polycations bearing quaternary ammonium moieties inhibit bacterial growth in vitro and have a potential use as additives in medical devices which need antibacterial properties.

  20. Synthesis of Chitosan Quaternary Ammonium Salts

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A series of N-alkyl or N-aryl chitosan quaternary ammonium salts were prepared via Schiffs base intermediates. Quaternization of N-substituted chitosan derivatives was carried out using methyl iodide to produce water-soluble cationic chitosan quaternary ammonium salt. The products were characterized by IR, 1HNMR and elemental analysis. The degree of substitution of chitosan quaternary ammonium salt was calculated by elemental analysis.

  1. Dissimilatory reduction of perchlorate and other common pollutants by a consortium enriched from tidal flats of the Yellow Sea

    Institute of Scientific and Technical Information of China (English)

    Nirmala Bardiya; Jae-Ho Bae

    2015-01-01

    Objective: To enrich a facultative anaerobic bacterial consortium from the Yellow Sea and assess its ability to reduce perchlorate and other co-pollutants. Methods: Bacterial consortium collected from the tidal flats of the Yellow Sea was enriched in an anoxic medium containing perchlorate as the electron (e-) acceptor and acetate as the electron (e-) donor. The enriched consortium was then tested for perchlorate reduction under different perchlorate concentrations and in the presence of nitrate by using standard anaerobic techniques. The complete enzymatic reduction of perchlorate to chloride was confirmed by chlorite dismutation. Ability of the consortium to grow with alternate e- acceptors was also tested with acetate as the e- donor. Results: The enriched consortium could rapidly reduce perchlorate up to the initial concentration of 25.65 mmol/L. In the presence of nitrate, perchlorate reduction did not occur immediately and reduction of nitrate started after a lag phase, with concomitant accumulation of nitrite. The perchlorate-enriched consortium could reduce chlorate, oxygen, Cr (VI), and selenate as the alternate e- acceptors but failed to utilize sulfate, thiosulfate, sulfite, and nitrite. Conclusions: The consortium from the tidal flats of the Yellow Sea could reduce perchlorate and co-contaminants such as chlorate, nitrate, Cr (VI), and selenate under heterotrophic conditions with acetate as the e- donor and carbon source. While perchlorate was completely dismutated into innocuous chloride and oxygen, accumulation of nitrite occurred during the reduction of nitrate.

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

    Directory of Open Access Journals (Sweden)

    Thiruvenkatachari Viraraghavan

    2009-04-01

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

  3. The Impact of Temperature on the Performance of Anaerobic Biological Treatment of Perchlorate in Drinking Water

    Science.gov (United States)

    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 ...

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

    Science.gov (United States)

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

  5. A rapid and simple method for the separation of TBP-dodecane by perchloric acid

    International Nuclear Information System (INIS)

    Organic solvents, including TBP etc., are widely used as an extractant, and treated and disposed by storage, incineration, and absorption into absorbent after they were used. Any of those methods does not aim at recycling of solvents, treating concurrently the extractant and the diluent without separating them. In this paper, a test is reported on the TBP-dodecane separation by perchloric acid for a separation test of the diluent from the extractant as a first step toward recycling. Basically this separation method is already reported by P. Mark et al. as a method for the analysis of TBP, but it requires a large amount of perchloric acid. With a further detailed study of the perchloric acid effects on the TBP-dodecane separation, it was made clear that the separation is possible by adding a fixed amount of TBP contacted with perchloric acid to the TBP-dodecane solvent. In this paper, its outline is presented. (author)

  6. Thermal decomposition characteristics of ammonium dinitramide. Part 1; Anmoniumu jinitoramido no netsubunkai tokusei. 1

    Energy Technology Data Exchange (ETDEWEB)

    Takishita, Y.; Teramoto, Y. [Japan Defence Agency, Tokyo (Japan)

    1997-02-28

    At present, the mainstream of the oxidizer of solid propellant used in defense and space exploitation is ammonium perchlorate (AP), while a large amount of hydrogen chloride is generated by AP-based propellant due to chlorine existing in AP molecules. Ammonium dinitramide (ADN) is paid attention recently as a new none-chlorine energetic oxidizer. ADN, with the specific driving force equal to that of AP, is expected as a propellant-oxidizer to meet simultaneously the demands for the improvement of concealment and the prevention of environmental pollution while the high specific driving force is maintained. In this study, thermal decomposition characteristics of ADN is investigated by thermal analysis and mass spectroscopy. The activation energies calculated based on velocity theory are 105kj/mole, 117kj/mole and 151kj/mole respectively at the initial temperature sought from thermal gravity (TG) curve, the peak temperature of decompositing calorification in differential thermal analysis curve, and the temperature from which weight loss is 50% in TG curve. 6 refs., 6 figs., 1 tab.

  7. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Science.gov (United States)

    2010-07-01

    ... nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126..., ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. (a) When any item of ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo...

  8. Ammonium-induced inhibition of ammonium-starved Nitrosomonas europaea cells in soil and sand slurries

    NARCIS (Netherlands)

    Gerards, S.; Duyts, H.; Laanbroek, H.J.

    1998-01-01

    Ammonia-oxidising bacteria are poor competitors for limiting amounts of ammonium. Hence, starvation for ammonium seems to be the regular condition for these bacteria in natural environments. Long-term survival in the absence of ammonium will be dependent on the ability to maintain large population s

  9. Preparation of perlite-based magnesium perchlorate desiccant with colour indicator.

    Science.gov (United States)

    Wu, L; He, H

    1994-05-01

    A new desiccant consisting of magnesium perchlorate, expanded perlite and metal chelate was prepared. The performance tests show that the desiccant is superior to magnesium perchlorate desiccant in dehydration efficiency, absorption capacity for water, flow resistance, color indicator and regeneration. It can reduce the amount of water in gases to approximately 0.7 ppm(v/v). Its applications in gas analysis and purification were investigated.

  10. Perchlorate in dust fall and indoor dust in Malta: An effect of fireworks.

    Science.gov (United States)

    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. PMID:25828411

  11. Perchlorate in dust fall and indoor dust in Malta: An effect of fireworks.

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

    Graphical abstract: The molecular geometry, electronic structure, infrared spectra, and heats of reaction and formation of cobalt and nickel tris(carbohydrazide) perchlorates as well as copper bis(carbohydrazide) perchlorate are investigated using the HSE screened hybrid density functional. The metal-ligand interaction, thermal stability, and red-shift of the amino stretching vibrations of these complexes are also discussed. Moreover, it is found there is a relationship between the energy gap and impact sensitivity. - Abstract: 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 σN-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.

  13. Microbial redox processes in deep subsurface environments and the potential application of (perchlorate in oil reservoirs

    Directory of Open Access Journals (Sweden)

    Martin G Liebensteiner

    2014-09-01

    Full Text Available The ability of microorganisms to thrive under oxygen-free conditions in subsurface environments relies on the enzymatic reduction of oxidized elements, such as sulfate, ferric iron or CO2, coupled to the oxidation of inorganic or organic compounds. A broad phylogenetic and functional diversity of microorganisms from subsurface environments has been described using isolation-based and advanced molecular ecological techniques. The physiological groups reviewed here comprise iron-, manganese- and nitrate-reducing microorganisms. In the context of recent findings also the potential of chlorate and perchlorate [jointly termed (perchlorate] reduction in oil reservoirs will be discussed. Special attention is given to elevated temperatures that are predominant in the deep subsurface. Microbial reduction of (perchlorate is a thermodynamically favorable redox process, also at high temperature. However, knowledge about (perchlorate reduction at elevated temperatures is still scarce and restricted to members of the Firmicutes and the archaeon Archaeoglobus fulgidus. By analyzing the diversity and phylogenetic distribution of functional genes in (metagenome databases and combining this knowledge with extrapolations to earlier-made physiological observations we speculate on the potential of (perchlorate reduction in the subsurface and more precisely oil fields. In addition, the application of (perchlorate for bioremediation, souring control and microbial enhanced oil recovery are addressed.

  14. Impacts of natural organic matter on perchlorate removal by an advanced reduction process.

    Science.gov (United States)

    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. PMID:24521418

  15. Preliminary analyses for perchlorate in selected natural materials and their derivative products

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2016-02-01

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

  17. Atmospheric behaviour of ammonia and ammonium.

    NARCIS (Netherlands)

    Asman, W.A.J.

    1987-01-01

    1.4.1 Scope of this thesisA few models for ammonia and ammonium exist. Russell et al. (1983) made a multi-layer Lagrangian transport model describing the transport and formation of ammonium nitrate aerosol for California. They did not take reactions of ammonia and sulphuric acid into account, nor we

  18. Inhibition of microbial sulfate reduction in a flow-through column system by (per)chlorate treatment

    OpenAIRE

    Anna eEngelbrektson; Christopher eHubbard; Lauren eTom; Aaron eBOUSSINA; Yong Tae eJin; Hayden eWong; Yvette Marisa Piceno; Hans Karl Carlson; Mark eConrad; Andersen, Gary L.; Coates, John D.

    2014-01-01

    Microbial sulfate reduction is a primary cause of oil reservoir souring. Here we show that amendment with chlorate or perchlorate [collectively (per)chlorate] potentially resolves this issue. Triplicate packed columns inoculated with marine sediment were flushed with coastal water amended with yeast extract and one of nitrate, chlorate, or perchlorate. Results showed that although sulfide production was dramatically reduced by all treatments, effluent sulfide was observed in the nitrate (10 m...

  19. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Science.gov (United States)

    2010-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  20. Study of microbial perchlorate reduction: Considering of multiple pH, electron acceptors and donors

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xing [Key Laboratory of Water Pollution Control and Recycling (Shandong), School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Gao, Baoyu, E-mail: bygao@sdu.edu.cn [Key Laboratory of Water Pollution Control and Recycling (Shandong), School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Jin, Bo [School of Chemical Engineering, The University of Adelaide, Adelaide SA 5005,Australia (Australia); Zhen, Hu [Key Laboratory of Water Pollution Control and Recycling (Shandong), School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Wang, Xiaoyi [CSIRO Land and Water, Gate 5, Waite Road, Urrbrae, SA 5064 (Australia); Dai, Ming [School of Chemical Engineering, The University of Adelaide, Adelaide SA 5005,Australia (Australia)

    2015-03-21

    Graphical abstract: Schemes of perchlorate reduction in ClO{sub 4}{sup −}/ClO{sub 3}{sup −}–NO{sub 3}{sup −} e{sup −}acceptor systems. - Highlights: • We created a multiple electron acceptor/donor system for ClO{sub 4}{sup −} reduction. • Nitrate reduction was inhibited when using perchlorate-grown Azospira sp. KJ. • Reduction proceeded as an order of ClO{sub 3}{sup −}, ClO{sub 4}{sup −}and NO{sub 3}{sup −}. • Oxidation of acetate was inhibited by succinate in acetate–succinate series. - Abstract: 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 ClO{sub 4}{sup −}–ClO{sub 3}{sup −}, ClO{sub 4}{sup −}–ClO{sub 3}{sup −}–NO{sub 3}{sup −},and ClO{sub 4}{sup −}–NO{sub 3}{sup −} acceptor systems, while being completely inhibited by the additional O{sub 2} in the ClO{sub 4}{sup −}–O{sub 2} acceptor system. The reduction proceeded as an order of ClO{sub 3}{sup −}, ClO{sub 4}{sup −}, and NO{sub 3}{sup −} in the ClO{sub 4}{sup −}–ClO{sub 3}{sup −}–NO{sub 3}{sup −} system. K{sub S,}v{sub max}, and q{sub max} obtained at different e{sup −} 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.

  1. Study of microbial perchlorate reduction: Considering of multiple pH, electron acceptors and donors

    International Nuclear Information System (INIS)

    Graphical abstract: Schemes of perchlorate reduction in ClO4−/ClO3−–NO3− e−acceptor systems. - Highlights: • We created a multiple electron acceptor/donor system for ClO4− reduction. • Nitrate reduction was inhibited when using perchlorate-grown Azospira sp. KJ. • Reduction proceeded as an order of ClO3−, ClO4−and NO3−. • Oxidation of acetate was inhibited by succinate in acetate–succinate series. - Abstract: 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. KS,vmax, and qmax 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

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

    Science.gov (United States)

    Navarro-Gonzalex, Rafael; Sutter, Brad; Archer, Doug; Ming, Doug; Eigenbrode, Jennifer; Franz, Heather; Glavin, Daniel; McAdam, Amy; Stern, Jennifer; McKay, Christopher; 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. Particle size distribution and perchlorate levels in settled dust from urban roads, parks, and roofs in Chengdu, China.

    Science.gov (United States)

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

    2016-01-01

    A total of 27 settled dust samples were collected from urban roads, parks, and roofs in Chengdu, China to investigate particle size distribution and perchlorate levels in different size fractions. Briefly, fine particle size fractions (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. PMID:26608047

  4. Ammonium and attachment of Rhodopirellula baltica.

    Science.gov (United States)

    Frank, Carsten S; Langhammer, Philipp; Fuchs, Bernhard Maximilian; Harder, Jens

    2011-05-01

    A dimorphic life cycle has been described for the planctomycete Rhodopirellula baltica SH1(T), with juvenile motile, free-swimming cells and adult sessile, attached-living cells. However, attachment as a response to environmental factors was not investigated. We studied the response of R. baltica to nitrogen limitation. In batch cultures, ammonium limitation coincided with a dominance of free-swimming cells and a low number of aggregates. Flow cytometry revealed a quantitative shift with increasing ammonium availability, from single cells towards attached cells in large aggregates. During growth of R. baltica on glucose and ammonium in chemostats, an ammonium addition caused a macroscopic change of the growth behaviour, from homogeneous growth in the liquid phase to a biofilm on the borosilicate glass wall of the chemostat vessel. Thus, an ammonium limitation-a carbon to nitrogen supply ratio of 30:1-sustained free-living growth without aggregate formation. A sudden increase in ammonium supply induced sessile growth of R. baltica. These observations reveal a response of Rhodopirellula baltica cells to ammonium: they abandon the free-swimming life, attach to particles and form biofilms. PMID:21340506

  5. Inhibition of microbial sulfate reduction in a flow-through column system by (perchlorate treatment

    Directory of Open Access Journals (Sweden)

    Anna eEngelbrektson

    2014-06-01

    Full Text Available Microbial sulfate reduction is a primary cause of oil reservoir souring. Here we show that amendment with chlorate or perchlorate [collectively (perchlorate] potentially resolves this issue. Triplicate packed columns inoculated with marine sediment were flushed with coastal water amended with yeast extract and one of nitrate, chlorate, or perchlorate. Results showed that although sulfide production was dramatically reduced by all treatments, effluent sulfide was observed in the nitrate (10 mM treatment after an initial inhibition period. In contrast, no effluent sulfide was observed with (perchlorate (10 mM. Microbial community analyses indicated temporal community shifts and phylogenetic clustering by treatment. Nitrate addition stimulated Xanthomonadaceae and Rhizobiaceae growth, supporting their role in nitrate metabolism. (Perchlorate showed distinct effects on microbial community structure compared with nitrate and resulted in a general suppression of the community relative to the untreated control combined with a significant decrease in sulfate reducing species abundance indicating specific toxicity. Furthermore, chlorate stimulated Pseudomonadaceae and Pseudoalteromonadaceae, members of which are known chlorate respirers, suggesting that chlorate may also control sulfidogenesis by biocompetitive exclusion of sulfate-reduction. Perchlorate addition stimulated Desulfobulbaceae and Desulfomonadaceae, which contain sulfide oxidizing and elemental sulfur-reducing species respectively, suggesting that effluent sulfide concentrations may be controlled through sulfur redox cycling in addition to toxicity and biocompetitive exclusion. Sulfur isotope analyses further support sulfur cycling in the columns, even when sulfide is not detected. This study indicates that (perchlorate show great promise as inhibitors of sulfidogenesis in natural communities and provides insight into which organisms and respiratory processes are involved.

  6. Hydrogen oxidation on gold electrode in perchloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-15

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

  7. Chlorine-36 abundance in natural and synthetic perchlorate

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

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

  8. NOVEL ASSOCIATIONS BETWEEN URINARY PERCHLORATE AND POTENTIALLY RELEVANT EFFECTS ON RISK FACTORS FOR HEART DISEASE BASED ON NHANES 2001-2002

    Science.gov (United States)

    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...

  9. Adaptive evolution of Desulfovibrio alaskensis G20 for developing resistance to perchlorate

    Science.gov (United States)

    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

  10. Highly Selective Perchlorate Membrane Electrode Based on Cobalt(Ⅲ) Schiff Base as a Neutral Carrier

    Institute of Scientific and Technical Information of China (English)

    SHOKROLLAHI Ardeshir; GHAEDI Mehrorang; RAJABI, Harold Reza; KIANFAR, Ali Hossein

    2009-01-01

    A highly selective poly(vinyl chloride) (PVC) membrane electrode based on Co(Ⅲ)-Schiff base [Co(5-NO2-Salen)(PBu3)]ClO4·H2O (where 5-NO2-SalenH=bis(5-nitrosalycilaldehyde)ethylenediamine) as a new carrier for construction of perchlorate-selective electrode by incorporating the membrane ingredients on the surface of a graphite electrodes has been reported. The proposed electrode possesses a very wide Nernestian potential linear range to perchlorate from 1.0×10-6 to 5.0×10-1 mol·L-1 with a slope of (59.4±0.9) mV per decade of perchlo-rate concentration with a low detection limit of 5.0×10-7 mol·L-1 and good perchlorate selectivity over the wide variety of other anions. The developed electrode has an especially fast response (<5 s) and a wide pH independent range (3.0-12.0) in comparison with recent reported electrodes and can be used for at least 2 months without any considerable divergence in their potential response. This electrode was used for the determination of perchlorate in river water, drinking water, sludgy water and human urine with satisfactory results without complicated and time consuming pretreatment.

  11. Developmental timing of sodium perchlorate exposure alters angiogenesis, thyroid follicle proliferation and sexual maturation in stickleback.

    Science.gov (United States)

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

    2015-08-01

    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 100mg/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 toward 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

  12. Perchlorate and Nitrate Remediation Efficiency and Microbial Diversity in a Containerized Wetland Bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. [Determination of iodide, thiocyanate and perchlorate ions in environmental water by two-dimensional ion chromatography].

    Science.gov (United States)

    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%.

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

    Science.gov (United States)

    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 (water and in well water. Analyses were performed by a commercial laboratory. Mechanisms of interaction are proposed. PMID:19123099

  15. Effects of lanthanum nitrate on growth and chlorophyll fluorescence characteristics of Alternanthera philoxeroides under perchlorate stress

    Institute of Scientific and Technical Information of China (English)

    谢寅峰; 蔡贤雷; 刘伟龙; 陶功胜; 陈倩; 张强

    2013-01-01

    To investigate the effects of exogenous lanthanum (La) on Alternanthera philoxeroides (Mart.) Griseb under perchlorate stress, changes in the growth and physiological parameters were investigated in solution culture experiments under controlled condi-tions. Different concentrations of La (NO3)3 were used in our study. It was shown that 0.1 and 0.5 mg/L La3+alleviated the inhibition effect of perchlorate on A. philoxeroides, including relative growth yield, dry weight of different organs, leaf area and root activity. And La3+prevented decline in the relative chlorophyll content and chlorophyll fluorescence parameters including Fv/Fm, Fv'/Fm',ΦPSI and ETR induced by perchlorate stress. Moreover, 0.5 mg/L La3+showed an optimal mitigative effect, while excess La3+(5.0 mg/L) led to synergistic effect on stress. Correlation analysis revealed a significant positive relationship between growth indexes and the chlorophyll fluorescence parameters, root activity and relative chlorophyll content (p<0.05). The results suggested that appropriate concentration of La3+could effectively alleviate growth inhibition and injury of A. philoxeroides caused by perchlorate stress, and the mitigative effect of La3+might be achieved by improving root activity, maintaining chlorophyll content and promoting photochemical efficiency of photosystem II of A. philoxeroides under perchlorate stress.

  16. Kinetics of nitrate and perchlorate reduction in ion exchange brine using the membrane biofilm reactor (MBfR)

    Science.gov (United States)

    Several sources of bacterial inocula were tested for their ability to reduce nitrate and perchlorate in synthetic ion-exchange spent brine (3-4.5% salinity) using a hydrogen-based membrane biofilm reactor (MBfR). Nitrate and perchlorate removal fluxes reached as high as 5.4 g N ...

  17. Martian Chlorine Chemistry: A Study of Perchlorate on the Martian Surface, Evidence of an Ongoing Formation Mechanism and Implications of a Complex Chlorine Cycle

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2015-07-01

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

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

    Science.gov (United States)

    Mukhi, S.; Patino, R.

    2007-01-01

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

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

    Science.gov (United States)

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

    2007-01-01

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

  1. Microbial perchlorate reduction: A precise laboratory determination of the chlorine isotope fractionation and its possible biochemical basis

    Science.gov (United States)

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

    2008-05-01

    Perchlorate-reducing bacteria fractionate chlorine stable isotopes giving a powerful approach to monitor the extent of microbial consumption of perchlorate in contaminated sites undergoing remediation or natural perchlorate containing sites. This study reports the full experimental data and methodology used to re-evaluate the chlorine isotope fractionation of perchlorate reduction in duplicate culture experiments of Azospira suillum strain PS at 37 °C (Δ 37Cl Cl --ClO 4-) previously reported, without a supporting data set by Coleman et al. [Coleman, M.L., Ader, M., Chaudhuri, S., Coates, J.D., 2003. Microbial Isotopic Fractionation of Perchlorate Chlorine. Appl. Environ. Microbiol. 69, 4997-5000] in a reconnaissance study, with the goal of increasing the accuracy and precision of the isotopic fractionation determination. The method fully described here for the first time, allows the determination of a higher precision Δ 37Cl Cl --ClO 4- value, either from accumulated chloride content and isotopic composition or from the residual perchlorate content and isotopic composition. The result sets agree perfectly, within error, giving average Δ 37Cl Cl --ClO 4- = - 14.94 ± 0.15‰. Complementary use of chloride and perchlorate data allowed the identification and rejection of poor quality data by applying mass and isotopic balance checks. This precise Δ 37Cl Cl --ClO 4- value can serve as a reference point for comparison with future in situ or microcosm studies but we also note its similarity to the theoretical equilibrium isotopic fractionation between a hypothetical chlorine species of redox state + 6 and perchlorate at 37 °C and suggest that the first electron transfer during perchlorate reduction may occur at isotopic equilibrium between an enzyme-bound chlorine and perchlorate.

  2. A low cost igniter utilizing an SCB and titanium sub-hydride potassium perchlorate pyrotechnic

    Science.gov (United States)

    Bickes, R. W., Jr.; Grubelich, M. C.; Hartman, J. K.; McCampbell, C. B.; Churchill, J. K.

    1994-01-01

    A conventional NSI (NASA Standard Initiator) normally employs a hot-wire ignition element to ignite ZPP (zirconium potassium perchlorate). With minor modifications to the interior of a header similar to an NSI device to accommodate an SCB (semiconductor bridge), a low cost initiator was obtained. In addition, the ZPP was replaced with THKP (titanium sub-hydride potassium perchlorate) to obtain increased overall gas production and reduced static-charge sensitivity. This paper reports on the all-fire and no-fire levels obtained and on a dual mix device that uses THKP as the igniter mix and a thermite as the output mix.

  3. Contact Electrification of Regolith Particles and Chloride Electrolysis: Synthesis of Perchlorates on Mars

    Science.gov (United States)

    Tennakone, K.

    2016-10-01

    Contact electrification of chloride-impregnated martian regolith particles due to eolian agitation and moisture condensation on coalesced oppositely charged grains may lead to spontaneous electrolysis that generates hypochlorite, chlorite, chlorate, and perchlorate with a concomitant reduction of water to hydrogen. This process is not curtailed even if moisture condenses as ice because chloride ionizes on the surface of ice. Limitations dictated by potentials needed for electrolysis and breakdown electric fields enable estimation of the required regolith grain size. The estimated dimension turns out to be of the same order of magnitude as the expected median size of martian regolith, and a simple calculation yields the optimum rate of perchlorate production.

  4. Natural Nitrogen—15 Abundance of Ammonium Nitrogen and Fixed Ammonium in Soils

    Institute of Scientific and Technical Information of China (English)

    SHISHU-LIAN; XINGGUANG-XI; 等

    1992-01-01

    The present article deals with the natural nitrogen-15 abundance of ammonium nitrogen and fixed ammonium in different soils.Variations in the natural 15N abundance of ammonium nitrogen mineralized in soils under anaerobic incubation condition were related to soil pH.The δ 15N of mineralizable N in acid soils was lower but that in neutral and calcareous soils was higher compared with the δ 15N of total N in the soils.A variation tendence was also found in the δ 15N of amino-acid N in the hydrolysates of soils.The natural 15N abundance of fixed ammonium was higher than that of total N in most surface soils and other soil horizons,indicating that the increase of δ 15N in the soil borizons beneath subsurface horizon of some forest soils and acid paddy soils was related to the higher δ 15N value of fixed ammonium in the soil.

  5. Benchmark binding energies of ammonium and alkyl-ammonium ions interacting with water. Are ammonium-water hydrogen bonds strong?

    Science.gov (United States)

    Vallet, Valérie; Masella, Michel

    2015-01-01

    Alkyl-ammonium ion/water interactions are investigated using high level quantum computations, yielding thermodynamics data in good agreement with gas-phase experiments. Alkylation and hydration lead to weaken the NHsbnd O hydrogen bonds. Upon complete hydration by four water molecules, their main features are close to those of the OHsbnd O bond in the isolated water dimer. Energy decomposition analyses indicate that hydration of alkyl-ammonium ions are mainly due to electrostatic/polarization effects, as for hard monoatomic cations, but with a larger effect of dispersion.

  6. Reduction in Ammonium Ions in Sludge Liquor

    Directory of Open Access Journals (Sweden)

    Eglė Šlajūtė

    2013-12-01

    Full Text Available Liquor rejected from the centrifugation of the digested sludge can contain the concentrations of ammonium ions up to 1750 mg/L. These loads are usually returned to the intake of wastewater treatment plants (WWTP without additional treatment and can have a negative impact on biological wastewater and/or sludge treatment processes, e.g. phosphorus and nitrogen removal. This article deals with the use of naturally obtained sorbent, zeolite, in batch and column test procedure for removing ammonium from the rejected liquor. This research study was carried out using different sizes of zeolite particles: 0.8–1.6 mm and 1.6–2.5 mm. The highest efficiency of ammonium removal (up to 98 % was achieved by applying the zeolite particles of 0.8–1.6 mm.Article in Lithuanian

  7. Reproductive toxicity screen of ammonium dinitramide administered in the drinking water of Sprague-Dawley rats.

    Science.gov (United States)

    Kinkead, E R; Wolfe, R E; Flemming, C D; Leahy, H F; Caldwell, D J; Miller, C R; Marit, G B

    1995-01-01

    The Department of Defense is currently considering replacing ammonium perchlorate with ammonium dinitramide (ADN), a class 1.1 explosive oxidizer to be used in solid rocket propellant mixtures and explosives. This study was intended to evaluate the potential of ADN to produce alterations in paternal fertility, maternal pregnancy and lactation, and growth and development of offspring. Male and female rats received drinking water containing 0.0, 0.2, 1.0, or 2.0 g ADN/liter throughout the study. Mating occurred following 14 days of treatment. All dams, one-half the males, and representative pups were maintained for a total of 90 days of treatment. No mortality occurred in parental animals during the study. Treatment with ADN resulted in no adverse effects on mating; 92-100% of the animals mated. No treatment-related effects were seen in parental animals clinically or histopathologically. Adverse treatment-related effects were noted in maternal and paternal fertility indices, gestational indices, and live birth indices in both the mid- and high-dose groups. Litter sizes in the mid- and high-dose groups were significantly smaller than those of the low-dose and control groups. Mean pup weights showed no statistically significant differences between ADN-treated pups and controls. Gross and histopathological examination of the animals failed to identify the cause for the decrease in litter production in the mid- and high-dose dams. This study indicates that ADN is a reproductive toxicant. The no-observable-effect level (NOEL) is 29 mg/kg/day, the median dose of the low level female rats. PMID:8748424

  8. Occupational Exposure in Ammonium Phosphate Fertilizer Plants

    International Nuclear Information System (INIS)

    Occupational exposures and activity concentrations have been assessed in two industrial plants producing mono-ammonium phosphate and di-ammonium phosphate fertilizers, located in south-western Spain. The annual effective doses received by the workers are below 1 mSv/a, with the contribution from external exposure being similar to that from internal exposure. The dose contribution from inhalation of dust has been estimated to be about 0.12 mSv/a, while the 222Rn concentrations inside the plants are of no concern. Consequently, no additional radiation protection measures need to be taken to protect the workers in these facilities. (author)

  9. Main Factors Effecting Anaerobic Ammonium Oxidation

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao-fei

    2014-01-01

    Anaerobic Ammonium Oxidation (ANAMMOX) drew more attentions because of its denitrification in wastewater with low carbon resource. The external conditions of ANAMMOX are relatively harsh,however this reaction does not require the participation of oxygen and organics. So the research and technology development of ANAMMOX has the significance of sustainable development.In this paper, the main influencing factors of ANAMMOX were summarized,Combined with recent research status of ANAMMOX technology, the development trend of the anaerobic ammonium oxidation technology was prospected.

  10. On the evaporation of ammonium sulfate solution

    Energy Technology Data Exchange (ETDEWEB)

    Drisdell, Walter S.; Saykally, Richard J.; Cohen, Ronald C.

    2009-07-16

    Aqueous evaporation and condensation kinetics are poorly understood, and uncertainties in their rates affect predictions of cloud behavior and therefore climate. We measured the cooling rate of 3 M ammonium sulfate droplets undergoing free evaporation via Raman thermometry. Analysis of the measurements yields a value of 0.58 {+-} 0.05 for the evaporation coefficient, identical to that previously determined for pure water. These results imply that subsaturated aqueous ammonium sulfate, which is the most abundant inorganic component of atmospheric aerosol, does not affect the vapor-liquid exchange mechanism for cloud droplets, despite reducing the saturation vapor pressure of water significantly.

  11. On the evaporation of ammonium sulfate solution.

    Science.gov (United States)

    Drisdell, Walter S; Saykally, Richard J; Cohen, Ronald C

    2009-11-10

    Aqueous evaporation and condensation kinetics are poorly understood, and uncertainties in their rates affect predictions of cloud behavior and therefore climate. We measured the cooling rate of 3 M ammonium sulfate droplets undergoing free evaporation via Raman thermometry. Analysis of the measurements yields a value of 0.58 +/- 0.05 for the evaporation coefficient, identical to that previously determined for pure water. These results imply that subsaturated aqueous ammonium sulfate, which is the most abundant inorganic component of atmospheric aerosol, does not affect the vapor-liquid exchange mechanism for cloud droplets, despite reducing the saturation vapor pressure of water significantly. PMID:19861551

  12. Kinetics of nitrate and perchlorate reduction in ion-exchange brine using the membrane biofilm reactor (MBfR).

    Science.gov (United States)

    Van Ginkel, Steven W; Ahn, Chang Hoon; Badruzzaman, Mohammad; Roberts, Deborah J; Lehman, S Geno; Adham, Samer S; Rittmann, Bruce E

    2008-09-01

    Several sources of bacterial inocula were tested for their ability to reduce nitrate and perchlorate in synthetic ion-exchange spent brine (30-45 g/L) using a hydrogen-based membrane biofilm reactor (MBfR). Nitrate and perchlorate removal fluxes reached as high as 5.4 g Nm(-2)d(-1) and 5.0 g ClO(4)m(-2)d(-1), respectively, and these values are similar to values obtained with freshwater MBfRs. Nitrate and perchlorate removal fluxes decreased with increasing salinity. The nitrate fluxes were roughly first order in H(2) pressure, but roughly zero-order with nitrate concentration. Perchlorate reduction rates were higher with lower nitrate loadings, compared to high nitrate loadings; this is a sign of competition for H(2). Nitrate and perchlorate reduction rates depended strongly on the inoculum. An inoculum that was well acclimated (years) to nitrate and perchlorate gave markedly faster removal kinetics than cultures that were acclimated for only a few months. These results underscore that the most successful MBfR bioreduction of nitrate and perchlorate in ion-exchange brine demands a well-acclimated inoculum and sufficient hydrogen availability.

  13. 高氯酸诺氟沙星铜(Ⅱ)%Norfloxacin Coppe(Ⅱ) Perchlorate

    Institute of Scientific and Technical Information of China (English)

    谢永荣; 叶琼; 熊仁根

    2004-01-01

    The hydrothermal treatment of Cu(ClO4)2·6H2O and Norfloxacin (H-Norf) afforded [Cu(H-Noff)2(ClO4)2] (1) in which center Cu has a square planar geometry while perchlorate just acts as charge balance anions. CCDC:140821.

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

    KAUST Repository

    Balk, Melike

    2010-08-03

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

  15. The Impact of Temperature on Anaerobic Biological Perchlorate Removal and Aerobic Polishing of the Effluent

    Science.gov (United States)

    This abstract describes a pilot-scale evaluation of anaerobic biological perchlorate (C1O4) removal followed by aerobic effluent polishing. The anaerobic biological contactor operated for 3.5 years. During that period, two effluent polishing evaluations, lasting 311 an...

  16. The Impact of Temperature on Anaerobic Biological Perchlorate Removal and Aerobic Polishing of the Effluent - paper

    Science.gov (United States)

    This abstract describes a pilot-scale evaluation of anaerobic biological perchlorate (C1O4) removal followed by aerobic effluent polishing. The anaerobic biological contactor operated for 3.5 years. During that period, two effluent polishing evaluations, lasting 311 an...

  17. Regioselective iodination of aromatic compounds with potassium iodide in the presence of benzyltriphenylphosphonium perchlorate

    Institute of Scientific and Technical Information of China (English)

    Jalal Albadi; Masoumeh Abedini; Nasir Iravani

    2012-01-01

    A simple and efficient method for the selective iodination of various aromatic compounds by using potassium iodide in the presence of benzyltriphenylphosphonium perchlorate,is reported.This method provides several advantages such as good selectivity between ortho and para positions of aromatic compounds and high yields of the products.

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

    Science.gov (United States)

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

  19. Preparation and Analysis of Solid Solutions in the Potassium Perchlorate-Permanganate System.

    Science.gov (United States)

    Johnson, Garrett K.

    1979-01-01

    Describes an experiment, designed for and tested in an advanced inorganic laboratory methods course for college seniors and graduate students, that prepares and analyzes several samples in the nearly ideal potassium perchlorate-permanganate solid solution series. The results are accounted for by a theoretical treatment based upon aqueous…

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

    Science.gov (United States)

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

    2012-01-01

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

  1. Reactive Transport Model of Sulfur Cycling as Impacted by Perchlorate and Nitrate Treatments.

    Science.gov (United States)

    Cheng, Yiwei; Hubbard, Christopher G; Li, Li; Bouskill, Nicholas; Molins, Sergi; Zheng, Liange; Sonnenthal, Eric; Conrad, Mark E; Engelbrektson, Anna; Coates, John D; Ajo-Franklin, Jonathan B

    2016-07-01

    Microbial souring in oil reservoirs produces toxic, corrosive hydrogen sulfide through microbial sulfate reduction, often accompanying (sea)water flooding during secondary oil recovery. With data from column experiments as constraints, we developed the first reactive-transport model of a new candidate inhibitor, perchlorate, and compared it with the commonly used inhibitor, nitrate. Our model provided a good fit to the data, which suggest that perchlorate is more effective than nitrate on a per mole of inhibitor basis. Critically, we used our model to gain insight into the underlying competing mechanisms controlling the action of each inhibitor. This analysis suggested that competition by heterotrophic perchlorate reducers and direct inhibition by nitrite produced from heterotrophic nitrate reduction were the most important mechanisms for the perchlorate and nitrate treatments, respectively, in the modeled column experiments. This work demonstrates modeling to be a powerful tool for increasing and testing our understanding of reservoir-souring generation, prevention, and remediation processes, allowing us to incorporate insights derived from laboratory experiments into a framework that can potentially be used to assess risk and design optimal treatment schemes. PMID:27267666

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2007-12-01

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

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

    Science.gov (United States)

    Hatzinger, P.B.; Böhlke, J.K.; Sturchio, N.C.; Gu, B.; Heraty, L.J.; Borden, R.C.

    2009-01-01

    Environmental context. Perchlorate (ClO4-) and nitrate (NO3-) are common co-contaminants in groundwater, with both natural and anthropogenic sources. Each of these compounds is biodegradable, so in situ enhanced bioremediation is one alternative for treating them in groundwater. Because bacteria typically fractionate isotopes during biodegradation, stable isotope analysis is increasingly used to distinguish this process from transport or mixing-related decreases in contaminant concentrations. However, for this technique to be useful in the field to monitor bioremediation progress, isotope fractionation must be quantified under relevant environmental conditions. In the present study, we quantify the apparent in situ fractionation effects for stable isotopes in ClO4- (Cl and O) and NO3- (N and O) resulting from biodegradation in an aquifer. Abstract. An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br- as a conservative tracer of the injectate), perchlorate concentrations decreased by 78% and nitrate concentrations decreased by 82% during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (18O/37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of ???0.8 (18O/15N), which is within the range of values

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

    Science.gov (United States)

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

    2013-10-01

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

  6. 76 FR 47238 - Ammonium Nitrate From Russia

    Science.gov (United States)

    2011-08-04

    ...)). Background The Commission instituted this review on March 1, 2011 (76 FR 11273) and determined on June 6, 2011 that it would conduct an expedited review (76 FR 34749, June 14, 2011). The Commission transmitted... COMMISSION Ammonium Nitrate From Russia Determination On the basis of the record \\1\\ developed in the...

  7. 21 CFR 184.1133 - Ammonium alginate.

    Science.gov (United States)

    2010-04-01

    ...: Category of food Maximum level of use in food (as served) (percent) Functional use Confections, frostings... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium alginate. 184.1133 Section 184.1133 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  8. Topaz concentrate desiliconization with ammonium bifluoride

    OpenAIRE

    Andreev, V. A.; Buynovskiy, A. S.; Andreev, Artyom Andreevich; Dyachenko, Alexander Nikolaevich

    2007-01-01

    Fluoridizing agent for the process of topaz concentrate desiliconization has been selected, topaz thermodynamic potentials have been appraised, thermodynamic probabilities of fluorination reaction of topaz concentrate main constituents have been calculated. The results of studying the concentrate desiliconization process with ammonium bifluoride by the methods of thermogravimetry, RFA, microphotography are presented

  9. Detonation characteristics of ammonium nitrate products

    NARCIS (Netherlands)

    Kersten, R.J.A.; Hengel, E.I.V. van den; Steen, A.C. van der

    2006-01-01

    The detonation properties of ammonium nitrate (AN) products depend on many factors and are therefore, despite the large amount of information on this topic, difficult to assess. In order to further improve the understanding of the safety properties of AN, the European Fertilizer Manufacturers Associ

  10. Ammonium ions determination with polypyrrole modified electrode

    Directory of Open Access Journals (Sweden)

    Luiz Henrique Dall´Antonia

    2007-03-01

    Full Text Available The present work relates the preparation of polypyrrole films (PPy deposited on surfaces of glass carbon, nickel and ITO (tin oxide doped with indium on PET plastic, in order to study the ammonium detection. The popypyrrole films were polymerized with dodecylbenzenesulfonate (DBSA on the electrodes, at + 0,70 V vs. Ag/AgCl, based on a solution containing the pyrrole monomer and the amphiphilic salt. Films deposited on glass carbon presented better performance. Cyclic voltammetries, between – 1,50 to + 0,5 V vs. Ag/AgCl, were repeated adding different concentrations of NH4Cl, in order to observe the behavior of the film as a possible detector of ions NH4+. The peak current for oxidation varies with the concentration of ammonium. A linear region can be observed in the band of 0 to 80 mM, with a sensibility (Sppy approximately similar to 4,2 mA mM-1 cm-2, showing the efficacy of the electrodes as sensors of ammonium ions. The amount of deposited polymer, controlled by the time of growth, does not influence on the sensor sensibility. The modified electrode was used to determine ammonium in grounded waters.

  11. 76 FR 46907 - Ammonium Nitrate Security Program

    Science.gov (United States)

    2011-08-03

    ... comments. SUMMARY: This proposed rule would implement anti-terrorism measures to better secure the homeland... purpose of preventing the use of ammonium nitrate in an act of terrorism. This proposed rule seeks comment... Administration POC Point of Contact QATT Qualified Anti-Terrorism Technology RFA Regulatory Flexibility...

  12. 40 CFR 721.4095 - Quaternary ammonium alkyltherpropyl trialkylamine halides.

    Science.gov (United States)

    2010-07-01

    ... trialkylamine halides. 721.4095 Section 721.4095 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.4095 Quaternary ammonium alkyltherpropyl trialkylamine halides. (a... generically as quaternary ammonium alkyltherpropyl trialkylamine halides (PMNs...

  13. Dissimilatory perchlorate reduction linked to aerobic methane oxidation via chlorite dismutase

    Science.gov (United States)

    Oremland, R. S.; Baesman, S. M.; Miller, L. G.

    2013-12-01

    The presence of methane (CH4) in the atmosphere of Mars is controversial yet the evidence has aroused scientific interest, as CH4 could be a harbinger of extant or extinct microbial life. There are various oxidized compounds present on the surface of Mars that could serve as electron acceptors for the anaerobic oxidation of CH4, including perchlorate (ClO4-). We examined the role of perchlorate, chlorate (ClO3-) and chlorite (ClO2-) as oxidants linked to CH4 oxidation. Dissimilatory perchlorate reduction begins with reduction of ClO4- to ClO2- and ends with dismutation of chlorite to yield chloride (Cl-) and molecular oxygen (O2). We explored the potential for aerobic CH4 oxidizing bacteria to couple with oxygen derived from chlorite dismutation during dissimilatory perchlorate reduction. Methane (0.2 kPa) was completely removed within several days from the N2-flushed headspace above cell suspensions of methanotrophs (Methylobacter albus strain BG8) and perchlorate reducing bacteria (Dechloromonas agitata strain CKB) in the presence of 5 mM ClO2-. Similar rates of CH4 consumption were observed for these mixed cultures whether they were co-mingled or segregated under a common headspace, indicating that direct contact of cells was not required for methane consumption to occur. We also observed complete removal of 0.2 kPa CH4 in bottles containing dried soil (enriched in methanotrophs by CH4 additions over several weeks) and D. agitata CKB and in the presence of 10 mM ClO2-. This soil (seasonally exposed sediment) collected from the shoreline of a freshwater lake (Searsville Lake, CA) demonstrated endogenous CH4 uptake as well as perchlorate, chlorate and chlorite reduction/dismutation. However, these experiments required physical separation of soil from the aqueous bacterial culture to allow for the partitioning of O2 liberated from chlorite dismutation into the shared headspace. Although dissimilatory reduction of ClO4- and ClO3- could be inferred from the

  14. Reaction of Elemol with Acetic acid –Perchloric acid: Characterization of a novel oxide and (+)-β-cyperone

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; Govenkar, M.B.; Paknikar, S.K.

    The minor unidentified compounds of acetic acid- perchloric acid dehydration of elemol (1) have been fully characterized. The structure and relative stereochemistry as shown in (2) of the less polar fragrant compound named as elemoxide was deduced...

  15. In situ bioremediation of nitrate and perchlorate in vadose zone soil for groundwater protection using gaseous electron donor injection technology.

    Science.gov (United States)

    Evans, Patrick J; Trute, Mary M

    2006-12-01

    When present in the vadose zone, potentially toxic nitrate and perchlorate anions can be persistent sources of groundwater contamination. Gaseous electron donor injection technology (GEDIT), an anaerobic variation of petroleum hydrocarbon bioventing, involves injecting electron donor gases, such as hydrogen or ethyl acetate, into the vadose zone, to stimulate biodegradation of nitrate and perchlorate. Laboratory microcosm studies demonstrated that hydrogen and ethanol promoted nitrate and perchlorate reduction in vadose zone soil and that moisture content was an important factor. Column studies demonstrated that transport of particular electron donors varied significantly; ethyl acetate and butyraldehyde were transported more rapidly than butyl acetate and ethanol. Nitrate removal in the column studies, up to 100%, was best promoted by ethyl acetate. Up to 39% perchlorate removal was achieved with ethanol and was limited by insufficient incubation time. The results demonstrate that GEDIT is a promising remediation technology warranting further validation.

  16. Potential Influence of Perchlorate on Heavy Metals and Organic Carbon in Serpentine Soil; Implications for Martian Regolith

    Science.gov (United States)

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

    2015-12-01

    Prasanna Kumarathilaka Chemical and Environmental Systems Modeling Research Group, National Institute of Fundamental Studies, Kandy, Sri LankaPerchlorate (ClO4-) concentrations as high as 1 Wt.% have been reported in Martian regolith. Perchlorate is a strong oxidizer capable of accelerating heavy and/or trace metal release into regolith/soil and reacting with organic matter/compounds (if present). Here, we assess interactions between perchlorate and an analogous Martian regolith (i.e., serpentine soil) to simulate and understand the fate of Mn, Ni and Co and organic carbon. Pre-characterized serpentine soil collected from Sri Lanka was used for this study. Incubation experiments were performed with three perchlorate concentrations (1, 0.75 and 0.5 w/w) and sequential and single extractions assessed solid phase metal fractionation in serpentine sediments after 3 weeks and 1 year, respectively. Additionally, total organic carbon (TOC) of the residues were analyzed. These experiments demonstrate a high release of Mn compared to Ni and Co. Metal concentrations in exchangeable and bioavailable fractions increased with increasing perchlorate concentrations. Exchangeable Ni, Mn and Co increased 5.9, 69.6 and 44.6% and bioavailable Ni, Mn and Co increased 5.5, 92.3 and 72.8%, respectively, after 1 year compared to 3 weeks. Additionally, TOC decreased with increasing perchlorate concentration. For example, TOC decreased by 14.3% after 1 year compared to a 3 week incubation period. Overall, this study confirms the accelerated release of metals and the removal of organic carbon with increasing perchlorate concentrations. Furthermore, this study illustrates how perchlorate may present additional challenges to current Martian life studies and the future human habitation of Mars.Prasanna Kumarathilaka Chemical and Environmental Systems Modeling Research Group, National Institute of Fundamental Studies, Kandy, Sri LankaPerchlorate (ClO4-) concentrations as high as 1 Wt.% have

  17. 21 CFR 184.1296 - Ferric ammonium citrate.

    Science.gov (United States)

    2010-04-01

    ... citrate (iron (III) ammonium citrate) is prepared by the reaction of ferric hydroxide with citric acid, followed by treatment with ammonium hydroxide, evaporating, and drying. The resulting product occurs in two forms depending on the stoichiometry of the initial reactants. (1) Ferric ammonium citrate (iron...

  18. 40 CFR 721.10099 - Dialkyl dimethyl ammonium carbonate (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Dialkyl dimethyl ammonium carbonate... Specific Chemical Substances § 721.10099 Dialkyl dimethyl ammonium carbonate (generic). (a) Chemical... as dialkyl dimethyl ammonium carbonate (1:1) (PMN P-03-715) is subject to reporting under...

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

    International Nuclear Information System (INIS)

    Perchlorate (ClO4−) interferes with uptake of iodide in humans. Emission inventories do not explain observed distributions. Ozone (O3) is implicated in the natural origin of ClO4−, and has increased since pre-industrial times. O3 produces ClO4−in vitro from Cl−, and plant tissues contain Cl− and redox reactions. We hypothesize that O3 exposure may induce plant synthesis of ClO4−. We exposed contrasting crop species to environmentally relevant O3 concentrations. In the absence of O3 exposure, species exhibited a large range of ClO4− accumulation but there was no relationship between leaf ClO4− and O3, whether expressed as exposure or cumulative flux (dose). Older, senescing leaves accumulated more ClO4− than younger leaves. O3 exposed vegetation is not a source of environmental ClO4−. There was evidence of enhanced ClO4− content in the soil surface at the highest O3 exposure, which could be a significant contributor to environmental ClO4−. -- Highlights: • Exposure to ozone in crop species does not induce accumulation nor biosynthesis of perchlorate. • Older leaves accumulate more perchlorate than younger leaves. • Soil surface may accumulate perchlorate following exposure to ozone. • Species differ greatly in accumulation of perchlorate from the rhizosphere, independent of ozone. • Ozone exposed vegetation is not a candidate source of environmental perchlorate. -- Exposure of crop species to ozone did not lead to biosynthesis or greater accumulation of foliar perchlorate. Older leaves accumulated more perchlorate than younger leaves

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

    Science.gov (United States)

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

    2007-01-01

    Perchlorate is a widespread environmental contaminant having both anthropogenic and natural sources. Stable isotope ratios of O and Cl in a given sample of perchlorate may be used to distinguish its source(s). Isotopic ratios may also be useful for identifying the extent of biodegradation of perchlorate, which is critical for assessing natural attenuation of this contaminant in groundwater. For this approach to be useful, however, the kinetic isotopic fractionations of O and Cl during perchlorate biodegradation must first be determined as a function of environmental variables such as temperature and bacterial species. A laboratory study was performed in which the O and Cl isotope ratios of perchlorate were monitored as a function of degradation by two separate bacterial strains (Azospira suillum JPLRND and Dechlorospirillum sp. FBR2) at both 10??C and 22??C with acetate as the electron donor. Perchlorate was completely reduced by both strains within 280 h at 22??C and 615 h at 10??C. Measured values of isotopic fractionation factors were ??18O = -36.6 to -29.0??? and ??37Cl = -14.5 to -11.5???, and these showed no apparent systematic variation with either temperature or bacterial strain. An experiment using 18O-enriched water (??18O = +198???) gave results indistinguishable from those observed in the isotopically normal water (??18O = -8.1???) used in the other experiments, indicating negligible isotope exchange between perchlorate and water during biodegradation. The fractionation factor ratio ??18O/??37Cl was nearly invariant in all experiments at 2.50 ?? 0.04. These data indicate that isotope ratio analysis will be useful for documenting perchlorate biodegradation in soils and groundwater. The establishment of a microbial fractionation factor ratio (??18O/??37Cl) also has significant implications for forensic studies. ?? 2007 American Chemical Society.

  1. Activity inhibition and its mitigation in high temperature proton exchange membrane fuel cells: The role of phosphoric acid, ammonium trifluoromethanesulfonate, and polyvinylidene difluoride

    Science.gov (United States)

    Holst-Olesen, Kaspar; Nesselberger, Markus; Perchthaler, Markus; Hacker, Viktor; Arenz, Matthias

    2014-12-01

    In the presented work we systematically study the influence of phosphoric acid, ammonium trifluoromethanesulfonate (ATFMS), and polyvinylidene difluoride (PVDF) on the oxygen reduction reaction (ORR) activity of carbon supported, Pt based catalysts. The influence of phosphoric acid is investigated in a mixed solution of perchloric acid with small amounts of phosphoric acid added. Thin-film rotating disk electrode (TF-RDE) measurements show that such a mixed electrolyte is advantageous as the oxygen reduction reaction (ORR) is inhibited without influencing the oxygen solubility in the electrolyte. In contrast to previous reports it is seen when investigating additives that ATFMS acts as a catalyst poison; whereas the results provide evidence of a better performance in case of the PVDF incorporated catalysts as compared to reference samples without PVDF. The technological relevance of the PVDF improvements and its stability over prolonged time was validated by membrane electrode assembly (MEA) tests.

  2. A Reservoir of Natural Perchlorate in Unsaturated Zones of Arid and Semi-Arid Regions, Southwestern USA

    Science.gov (United States)

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

    2006-12-01

    Natural perchlorate (ClO4-) is generally present in unsaturated zones of steppe-to-desert regions of the arid and semi-arid southwestern United States. The perchlorate is associated with atmospherically deposited chloride that has accumulated throughout the Holocene. To assess this natural reservoir, we analyzed unsaturated-zone profiles from ten sites across Nevada, New Mexico, Texas, and Utah for perchlorate and other anions. The sampled sites represent a wide range of precipitation (0.1 0.5 m yr-1), dominant vegetation, soil type, underlying geology, and include five distinct ecological regions: Chihuahuan, Mojave, and southern Great Basin deserts; Arizona-New Mexico semi-desert; and Texas High Plains dry steppe. Concentrations of perchlorate correlated closely with chloride and bromide. The perchlorate reservoir (up to 1 kg ha-1) is sufficiently large to impact groundwater when natural recharge during pluvial periods or induced recharge after conversion to agriculture flushes accumulated salts from the unsaturated zone. This little explored source can explain perchlorate in milk and other agricultural products far from anthropogenic contamination, and should be considered when evaluating overall exposure risk.

  3. Detonation Properties of Ammonium Dinitramide (ADN)

    Science.gov (United States)

    Wätterstam, A.; Östmark, H.; Helte, A.; Karlsson, S.

    1999-06-01

    Ammonium Dinitramide, ADN, has a potential as an oxidizer for underwater high explosives. Pure ADN has a large reaction-zone length and shows a strong non-ideal behaviour. The work presented here is an extension of previous work.(Sensitivity and Performance Characterization of Ammonium Dinitramide (ADN). Presented at 11th International Detonation Symposium, Snowmass, CO, 1998.) Experiments for determining the detonation velocity as a function of inverse charge radius and density, reaction-zone length and curvature, and the detonation pressure are presented. Measurements of pressure indicates that no, or weak von-Neumann spike exists, suggesting an immediate chemical decomposition. Experimental data are compared with predicted using thermochemical codes and ZND-theory.

  4. Development of technology for ammonium nitrate dissociation process

    International Nuclear Information System (INIS)

    Ammonia and ammonium carbonate are frequently used as reagents in fuel production and processing of liquid radioactive wastes. In particular, liquid radioactive wastes that contain ammonium nitrate are generated during operations of metal precipitation. In closed vessels at elevated temperature, for example in evaporators or deposits in tubing, ammonium nitrate may explode due to generation of gaseous nitrogen oxides [2]. In this connection, steps have to be taken to rule out conditions that result in explosion. To do that, ammonium nitrate should be removed even prior to the initial stage of its formation. This report gives results of development of a method of dissociating ammonium nitrate

  5. Secondary transformation mechanism of paramagnetic centers in irradiated alkali metal perchlorates

    International Nuclear Information System (INIS)

    The EPR method has been used to study thermal transformations of paramagnetic centres (PC) in X-ray irradiated potassium, rubidium and cesium perchlorates. Experimental data make it possible to suppose that diffusion coefficient of O- ion a rather high and this ion is freely diffused already at 262 K. Colliding with [MeClO4]+ centres it is transformed in a molecule of oxygen. Another part of O- is transformed in stable ozonide-ion at 300 K. About room temperature hole centres dissociate with formation of ClO2 radical. It is supposed that part of electron and hole centres is not stabilized but at 77 K it is transformed in stable radiolysis products. This process most effective proceeds in dislocations and on the surface of microcrystals. The suggested model of thermal transformations of primary PC in irradiated perchlorates of alkali metals explains formation of all the finite ion and paramagnetic radiolysis products

  6. The processing, properties and use of the pyrotechnic mixture titanium subhydride/potassium perchlorate

    Energy Technology Data Exchange (ETDEWEB)

    Massis, T.M.

    1996-07-01

    Development of this pyrotechnic occurred because of the need for a static insensitive material to meet personnel safety requirements and related system safety issues in nuclear weapon energetic material component designs. Ti subhydride materials are made by the thermal dehydrding of commercial Ti hydride powder to the desired equivalent hydrogen composition in the Ti lattice. These Ti subhydrides, when blended with K perchlorate, meet the static insensitivity requirement of not being initiated from an equivalent human body electrostatic discharge. Individual material and blend qualification requirements provide a reproducible material from lot to lot. These pyrotechnic formulations meet the high reliability requirements (0.9995) for initiation and performance parameters and have the necessary stability and compatibility to meet long lived requirements of more than 25 years. Various experiences and problems are also discussed that have led to a mature technology for Ti subhydride/K perchlorate during its use in energetic material component designs.

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

    Science.gov (United States)

    Sutter, B.; Heil, E.; Morris, R. V.; Archer, P. D.; Ming, D. W.; Niles, P. B.; Eigenbrode, J. L.; Franz, H.; Freissinet C.; Glavin, D. P.; McAdam, A. C.; Mahaffy, P.; Martin-Torres, F. Javier; Navarro-Gonzalez, R.; Paz-Zorzano, Maria; Stern, J. C.; McKay, C. P.

    2015-01-01

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

  8. Composition change of uranium perchlorates with organic ligands upon mechanochemical activation of exchange processes

    Science.gov (United States)

    Zazhogin, A. P.; Zazhogin, A. A.; Komyak, A. I.; Umreiko, D. S.

    2008-03-01

    Results of studies on the effect of mechanochemical activation of ligand exchange processes in uranyl perchlorate-dimethylsulfoxide are presented. Spectroscopic data show that mechanical activation of the exchange process in this system results in the replacement of H2O in the first coordination sphere of uranyl UO{2/2+} by DMSO to form nanocrystals with a defined ligand sphere. Possible factors governing the noted features are considered.

  9. Sweet and Sour: Attenuating Sulfidogenesis in an Advective Flow Column System with Perchlorate or Nitrate Treatment

    Science.gov (United States)

    Engelbrektson, A. L.; Hubbard, C. G.; Piceno, Y.; Boussina, A.; Jin, Y.; Dubinsky, E. A.; Tom, L.; Hu, P.; Conrad, M. E.; Anderson, G. L.; Coates, J. D.

    2013-12-01

    Hydrogen sulfide (H2S) biogenesis in oil reservoirs is a primary cause of souring and of associated costs in reservoir and pipeline maintenance. In addition to the corrosive effects of the H2S itself, abiotic and biological oxidation also generates sulfuric acid, further degrading metallic surfaces. Amending these environments with perchlorate (ClO4-) resolves these problems by inhibition of biological sulfate reduction and re-oxidation of H2S to elemental sulfur by dissimilatory (per)chlorate reducing bacteria (DPRB). Triplicate flow through columns packed with San Francisco bay sediment were flushed with bay water ([SO4=] = 25-30 mM) containing yeast extract with 50 mM inhibitor concentrations (NO3-or ClO4-) decreasing to 25 mM and finally 12.5 mM. Influent and effluent geochemistry was monitored and DNA was prepared from the sediment bed for microbial community analysis. Souring was reversed by both treatments (at 50 mM) compared to the control columns that had no ion addition. Nitrate began to re-sour when treatment concentration was decreased to 25 mM but treatment had to be decreased to 12.5 mM before the perchlorate treated columns began to re-sour. However, the treated columns re-soured to a lesser extent than the control columns. Phylochip microbial community analyses indicated microbial community shifts and phylogenetic clustering by treatment. Isotopic analysis of sulfate showed trends that broadly agreed with the geochemistry but also suggested further sulfur cycling was occurring. This study indicates that perchlorate shows great promise as an inhibitor of sulfidogenesis in natural communities and provides insight into which organisms are involved in this process.

  10. Electrochromic iridium oxide films: Compatibility with propionic acid, potassium hydroxide, and lithium perchlorate in propylene carbonate

    OpenAIRE

    Wen, Rui-Tao; Niklasson, Gunnar A.; Granqvist, Claes G.

    2013-01-01

    Porous thin films of It oxide were prepared by reactive dc magnetron sputtering onto unheated substrates. The crystallite size was similar to 5 nm, and a small amount of unoxidized Ir was present. The electrochromic performance was studied by optical transmittance measurements and cyclic voltammetry applied to films in aqueous and non-aqueous electrolytes, specifically being 1 M propionic acid, 1 M potassium hydroxide (KOH), and 1 M lithium perchlorate in propylene carbonate (Li-PC). Cyclic v...

  11. Disproportionation of plutonium IV in concentrated solutions of plutonium in perchloric acid

    International Nuclear Information System (INIS)

    This work was carried out to study the dependence of the PuIV disproportionation reaction in perchloric acid solution on the plutonium concentration up to 20 g/l. Solutions of such high plutonium concentration have not previously been studied. It was found that the bimolecular rate constant and the equilibrium constant of the disproportionation reaction were not appreciably different from their values at lower concentrations. (author)

  12. The ionic product of water in highly concentrated sodium perchlorate solutions.

    Science.gov (United States)

    Turonek, M L; Hefter, G T; May, P M

    1998-03-01

    The ionic product of water, pK(w)=-log[H(+)][OH(-)], has been determined in aqueous solutions of sodium perchlorate over the concentration range of 1.0-8.0 M at 25 degrees C from high-precision potentiometric titrations carried out in cells with liquid junction using both glass and hydrogen electrodes. The glass electrode results are systematically lower probably as a result of interference by Na(+) ions.

  13. The use of chlorate, nitrate, and perchlorate to promote crude oil mineralization in salt marsh sediments.

    Science.gov (United States)

    Brundrett, Maeghan; Horita, Juske; Anderson, Todd; Pardue, John; Reible, Danny; Jackson, W Andrew

    2015-10-01

    Due to the high volume of crude oil released by the Deepwater Horizon oil spill, the salt marshes along the gulf coast were contaminated with crude oil. Biodegradation of crude oil in salt marshes is primarily limited by oxygen availability due to the high organic carbon content of the soil, high flux rate of S(2-), and saturated conditions. Chlorate, nitrate, and perchlorate were evaluated for use as electron acceptors in comparison to oxygen by comparing oil transformation and mineralization in mesocosms consisting of oiled salt marsh sediment from an area impacted by the BP Horizon oil spill. Mineralization rates were determined by measuring CO2 production and δ (13)C of the produced CO2 and compared to transformation evaluated by measuring the alkane/hopane ratios over a 4-month period. Total alkane/hopane ratios decreased (~55-70 %) for all treatments in the following relative order: aerated ≈ chlorate > nitrate > perchlorate. Total CO2 produced was similar between treatments ranging from 550-700 mg CO2-C. The δ (13)C-CO2 values generally ranged between the indigenous carbon and oil values (-17 and -27‰, respectively). Oil mineralization was greatest for the aerated treatments and least for the perchlorate amended. Our results indicate that chlorate has a similar potential as oxygen to support oil mineralization in contaminated salt marshes, but nitrate and perchlorate were less effective. The use of chlorate as a means to promote oil mineralization in situ may be a promising means to remediate contaminated salt marshes while preventing unwanted secondary impacts related to nutrient management as in the case of nitrate amendments. PMID:25854211

  14. Widespread occurrence of perchlorate in water, foodstuffs and human urine collected from Kuwait and its contribution to human exposure.

    Science.gov (United States)

    Alomirah, Husam F; Al-Zenki, Sameer F; Alaswad, Marivi C; Alruwaih, Noor A; Wu, Qian; Kannan, Kurunthachalam

    2016-06-01

    Perchlorate is a thyroid hormone-disrupting compound and is reported to occur widely in the environment. Little is known on human exposure to perchlorate in Kuwait. In this study, 218 water samples, 618 commonly consumed foodstuffs and 532 urine samples collected from Kuwait were analysed to assess the exposure of the Kuwaiti population to perchlorate. For the estimation of daily intake of perchlorate, food consumption rates were obtained from the National Nutrition Survey in the State of Kuwait (NNSSK). The results showed that leafy vegetables accounted for a major share of perchlorate exposure among the Kuwaiti population at 0.062 µg kg(-)(1) bw day(-)(1) (36.2%), followed by fruits at 0.026 µg kg(-)(1) bw day(-)(1) (15.3%) and non-leafy vegetables at 0.017 µg kg(-)(1) bw day(-)(1) (10.1%). The urinary perchlorate geometric mean (GM) concentrations ranged from 8.51 to 17.1 µg l(-)(1) for the five age groups, which were higher than those reported in other countries. The estimated urinary perchlorate exposure for the Kuwaiti general population was 0.42 µg kg(-)(1) bw day(-)(1), which was higher than that reported for the United States. The dietary intake of perchlorate for the Kuwaiti population ranged from 0.14 to 0.67 µg kg(-)(1) bw day(-)(1) for the five age groups, with a mean total daily intake of 0.17 µg kg(-)(1) bw day(-)(1) for the general population. The highest estimated dietary mean daily intake of perchlorate (0.67 µg kg(-)(1) bw day(-)(1)) was found for children at 3-5 years. The estimated dietary perchlorate exposure in Kuwait is higher than the recommended mean reference dose (RfD) but lower than that of provisional maximum tolerable daily intake (PMTDI) set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). PMID:27248576

  15. Temporal and spatial variation of perchlorate in streambed sediments: results from in-situ dialysis samplers

    International Nuclear Information System (INIS)

    The fate of perchlorate (ClO4-) in streambed sediments is becoming a concern due to the increasing number of groundwater and surface water contamination sites in the United States. Dialysis samplers were deployed at three sites over a period of 1 year to determine the vertical distribution of ClO4-in sediment pore water. Results indicated that the spatial and temporal ClO4-penetration into sediments could be affected by numerous factors, such as temperature, microbial degradation, ClO4-surface water concentration, and sediment physico-geological properties. In general, maximum ClO4-penetration into sediments at the studied sites was 30 cm below the sediment-water surface. The vertical sequential depletion of electron acceptors in sediments suggested that microbial reduction was responsible for ClO4-depletion in stream sediments. Biodegradation of ClO4-occurred over a seasonally variable active depth zone of 1-10 cm. Results implied that there was a rapid natural attenuation potential of perchlorate in saturated near-surface sediments. -Perchlorate may be rapidly attenuated in saturated near-surface sediments

  16. Research Advances: Perchlorate in Dairy and Breast Milk Samples; NO Glow on Mars; Physical Chemistry to the Rescue: Differentiating Nicotinic and Cholinergic Agonists

    Science.gov (United States)

    King, Angela G.

    2005-07-01

    Perchlorate levels in milk suggest widespread presence of the chemical. NO emissions indicate circulation in Martian atmosphere. Modeling reveals subtle differences in drug membrane receptor interactions.

  17. Inhibition of microbial sulfate reduction in a flow-through column system by (per)chlorate treatment.

    Science.gov (United States)

    Engelbrektson, Anna; Hubbard, Christopher G; Tom, Lauren M; Boussina, Aaron; Jin, Yong T; Wong, Hayden; Piceno, Yvette M; Carlson, Hans K; Conrad, Mark E; Anderson, Gary; Coates, John D

    2014-01-01

    Microbial sulfate reduction is a primary cause of oil reservoir souring. Here we show that amendment with chlorate or perchlorate [collectively (per)chlorate] potentially resolves this issue. Triplicate packed columns inoculated with marine sediment were flushed with coastal water amended with yeast extract and one of nitrate, chlorate, or perchlorate. Results showed that although sulfide production was dramatically reduced by all treatments, effluent sulfide was observed in the nitrate (10 mM) treatment after an initial inhibition period. In contrast, no effluent sulfide was observed with (per)chlorate (10 mM). Microbial community analyses indicated temporal community shifts and phylogenetic clustering by treatment. Nitrate addition stimulated Xanthomonadaceae and Rhizobiaceae growth, supporting their role in nitrate metabolism. (Per)chlorate showed distinct effects on microbial community structure compared with nitrate and resulted in a general suppression of the community relative to the untreated control combined with a significant decrease in sulfate reducing species abundance indicating specific toxicity. Furthermore, chlorate stimulated Pseudomonadaceae and Pseudoalteromonadaceae, members of which are known chlorate respirers, suggesting that chlorate may also control sulfidogenesis by biocompetitive exclusion of sulfate-reduction. Perchlorate addition stimulated Desulfobulbaceae and Desulfomonadaceae, which contain sulfide oxidizing and elemental sulfur-reducing species respectively, suggesting that effluent sulfide concentrations may be controlled through sulfur redox cycling in addition to toxicity and biocompetitive exclusion. Sulfur isotope analyses further support sulfur cycling in the columns, even when sulfide is not detected. This study indicates that (per)chlorate show great promise as inhibitors of sulfidogenesis in natural communities and provides insight into which organisms and respiratory processes are involved. PMID:25071731

  18. Review:Anaerobic ammonium oxidation for treatment of ammonium-rich wastewaters

    Institute of Scientific and Technical Information of China (English)

    Lei ZHANG; Ping ZHENG; Chongojian TANG; Ren-cun JIN

    2008-01-01

    The concept of anaerobic ammonium oxidation (ANAMMOX) is presently of great interest.The functional bacteria belonging to the Planctomycete phylum and their metabolism are investigated by microbiologists.Meanwhile,the ANAMMOX is equally valuable in treatment of ammonium-rich wastewaters.Related processes including partial nitritation-ANAMMOX and completely autotrophic nitrogen removal over nitrite (CANON) have been developed,and lab-scale experiments proved that both processes were quite feasible in engineering with appropriate control.Successful full-scale practice in the Netherlands will ac-celerate application of the process in future.This review introduces the microbiology and more focuses on application of the ANAMMOX process.

  19. Review: Mechanisms of ammonium toxicity and the quest for tolerance.

    Science.gov (United States)

    Esteban, Raquel; Ariz, Idoia; Cruz, Cristina; Moran, Jose Fernando

    2016-07-01

    Ammonium sensitivity of plants is a worldwide problem, constraining crop production. Prolonged application of ammonium as the sole nitrogen source may result in physiological and morphological disorders that lead to decreased plant growth and toxicity. The main causes of ammonium toxicity/tolerance described until now include high ammonium assimilation by plants and/or low sensitivity to external pH acidification. The various ammonium transport-related components, especially the non-electrogenic influx of NH3 (related to the depletion of (15)N) and the electrogenic influx of NH4(+), may contribute to ammonium accumulation, and therefore to NH3 toxicity. However, this accumulation may be influenced by increasing K(+) concentration in the root medium. Recently, new insights have been provided by "omics" studies, leading to a suggested involvement of GDP mannose-pyrophosphorylase in the response pathways of NH4(+) stress. In this review, we highlight the cross-talk signaling between nitrate, auxins and NO, and the importance of the connection of the plants' urea cycle to metabolism of polyamines. Overall, the tolerance and amelioration of ammonium toxicity are outlined to improve the yield of ammonium-grown plants. This review identifies future directions of research, focusing on the putative importance of aquaporins in ammonium influx, and on genes involved in ammonium sensitivity and tolerance. PMID:27181951

  20. Rapid measurement of perchlorate in polar ice cores down to sub-ng L(-1) levels without pre-concentration.

    Science.gov (United States)

    Peterson, Kari; Cole-Dai, Jihong; Brandis, Derek; Cox, Thomas; Splett, Scott

    2015-10-01

    An ion chromatography-electrospray ionization-tandem mass spectrometry (IC-ESI-MS/MS) method has been developed for rapid and accurate measurement of perchlorate in polar snow and ice core samples in which perchlorate concentrations are expected to be as low as 0.1 ng L(-1). Separation of perchlorate from major inorganic species in snow is achieved with an ion chromatography system interfaced to an AB SCIEX triple quadrupole mass spectrometer operating in multiple reaction monitoring mode. Under optimized conditions, the limit of detection and lower limit of quantification without pre-concentration have been determined to be 0.1 and 0.3 ng L(-1), respectively, with a linear dynamic range of 0.3-10.0 ng L(-1) in routine measurement. These represent improvements over previously reported methods using similar analytical techniques. The improved method allows fast, accurate, and reproducible perchlorate quantification down to the sub-ng L(-1) level and will facilitate perchlorate measurement in the study of natural perchlorate production with polar ice cores in which perchlorate concentrations are anticipated to vary in the low and sub-ng L(-1) range. Initial measurements of perchlorate in ice core samples from central Greenland show that typical perchlorate concentrations in snow dated prior to the Industrial Revolution are about 0.8 ng L(-1), while perchlorate concentrations are significantly higher in recent (post-1980) snow, suggesting that anthropogenic sources are a significant contributor to perchlorate in the current environment. PMID:26297465

  1. [Achievement of Sulfate-Reducing Anaerobic Ammonium Oxidation Reactor Started with Nitrate-Reducting Anaerobic Ammonium Oxidation].

    Science.gov (United States)

    Liu, Zheng-chuan; Yuan, Lin-jiang; Zhou, Guo-biao; Li, Jing

    2015-09-01

    The transformation of nitrite-reducing anaerobic ammonium oxidation to sulfate-reducing anaerobic ammonium oxidation in an UASB was performed and the changes in microbial community were studied. The result showed that the sulfate reducing anaerobic ammonium oxidation process was successfully accomplished after 177 days' operation. The removal rate of ammonium nitrogen and sulfate were up to 58. 9% and 15. 7%, the removing load of ammonium nitrogen and sulfate were 74. 3 mg.(L.d)-1 and 77. 5 mg.(L.d)-1 while concentration of ammonium nitrogen and sulfate of influent were 130 mg.(L.d)-1 and 500 mg.(L.d)-1, respectively. The lost nitrogen and sulphur was around 2 in molar ratio. The pH value of the effluent was lower than that of the influent. Instead of Candidatus brocadia in nitrite reducing anaerobic ammonium oxidation granular sludge, Bacillus benzoevorans became the dominant species in sulfate reducing anaerobic ammonium oxidation sludge. The dominant bacterium in the two kinds of anaerobic ammonium oxidation process is different. Our results imply that the two anaerobic ammonium oxidation processes are carried out by different kind of bacterium. PMID:26717697

  2. Comparison of biotic and abiotic treatment approaches for co-mingled perchlorate, nitrate, and nitramine explosives in groundwater

    Science.gov (United States)

    Schaefer, C. E.; Fuller, M. E.; Condee, C. W.; Lowey, J. M.; Hatzinger, P. B.

    2007-01-01

    Biological and abiotic approaches for treating co-mingled perchlorate, nitrate, and nitramine explosives in groundwater were compared in microcosm and column studies. In microcosms, microscale zero-valent iron (mZVI), nanoscale zero-valent iron (nZVI), and nickel catalyzed the reduction of RDX and HMX from initial concentrations of 9 and 1 mg/L, respectively, to below detection (0.02 mg/L), within 2 h. The mZVI and nZVI also degraded nitrate (3 mg/L) to below 0.4 mg/L, but none of the metal catalysts were observed to appreciably reduce perchlorate (˜ 5 mg/L) in microcosms. Perchlorate losses were observed after approximately 2 months in columns of aquifer solids treated with mZVI, but this decline appears to be the result of biodegradation rather than abiotic reduction. An emulsified vegetable oil substrate was observed to effectively promote the biological reduction of nitrate, RDX and perchlorate in microcosms, and all four target contaminants in the flow-through columns. Nitrate and perchlorate were biodegraded most rapidly, followed by RDX and then HMX, although the rates of biological reduction for the nitramine explosives were appreciably slower than observed for mZVI or nickel. A model was developed to compare contaminant degradation mechanisms and rates between the biotic and abiotic treatments.

  3. Quaternary Ammonium Polyethyleneimine: Antibacterial Activity Ira

    International Nuclear Information System (INIS)

    Quaternary ammonium polyethyleneimine- (QA-PEI-) based nanoparticles were synthesized using two synthetic methods, reductive amination and N-alkylation. According to the first method, QA-PEI nanoparticles were synthesized by cross-linking with glutaraldehyde followed by reductive amination with octanal and further N-methylation with methyl iodide. The second method is based on crosslinking with dialkyl halide followed by N-alkylation with octyl halide and further N-methylation with methyl iodide. QA-PEI nanoparticles completely inhibited bacterial growth (>106 bacteria), including both Gram-positive, that is, Staphylococcus aureus at 80 μ/mL, and Gram-negative, that is, Escherichia coli at 320 μ/mL. Activity analysis revealed that the degree of alkylation and N-methylation of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl alkylated QA-PEI alkylated at 1 : 1 mole ratio (primary amine of PEI monomer units/alkylating agent). Also, cytotoxicity studies on MAT-LyLu and MBT cell lines were performed with QA-PEI nanoparticles. These findings confirm previous reports that poly cations bearing quaternary ammonium moieties inhibit bacterial growth in vitro and have a potential use as additives in medical devices which need antibacterial properties.

  4. Reassimilation of ammonium in Lotus japonicus.

    Science.gov (United States)

    Betti, Marco; García-Calderón, Margarita; Pérez-Delgado, Carmen M; Credali, Alfredo; Pal'ove-Balang, Peter; Estivill, Guillermo; Repčák, Miroslav; Vega, José M; Galván, Francisco; Márquez, Antonio J

    2014-10-01

    This review summarizes the most recent results obtained in the analysis of two important metabolic pathways involved in the release of internal sources of ammonium in the model legume Lotus japonicus: photorespiratory metabolism and asparagine breakdown mediated by aparaginase (NSE). The use of photorespiratory mutants deficient in plastidic glutamine synthetase (GS2) enabled us to investigate the transcriptomics and metabolomic changes associated with photorespiratory ammonium accumulation in this plant. The results obtained indicate the existence of a coordinate regulation of genes involved in photorespiratory metabolism. Other types of evidence illustrate the multiple interconnections existing among the photorespiratory pathway and other processes such as intermediate metabolism, nodule function, and secondary metabolism in this plant, all of which are substantially affected in GS2-deficient mutants because of the impairment of the photorespiratory cycle. Finally, the importance of asparagine metabolism in L. japonicus is highlighted because of the fact that asparagine constitutes the vast majority of the reduced nitrogen translocated between different organs of this plant. The different types of NSE enzymes and genes which are present in L. japonicus are described. There is a particular focus on the most abundant K(+)-dependent LjNSE1 isoform and how TILLING mutants were used to demonstrate by reverse genetics the importance of this particular isoform in plant growth and seed production.

  5. Light and variable 37Cl/35Cl ratios in rocks from Gale Crater, Mars: Possible signature of perchlorate

    Science.gov (United States)

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

    2016-03-01

    Cl isotope ratios measured on HCl thermally evolved from as-yet-unknown phases in sedimentary rocks and sand in Gale Crater provide unexpected insights to the Martian surficial Cl cycle. The seven samples yield δ37Cl values ranging from - 1 ± 25 ‰ to - 51 ± 5 ‰. Five analyses from two samples of the Sheepbed mudstone (Yellowknife Bay study area) are analytically indistinguishable with a mean δ37Cl of - 11 ± 7 ‰ (1 σ). In contrast, four mudstones/sandstones from the Kimberley and Pahrump study areas also yielded indistinguishable ratios, but with a mean δ37Cl of - 43 ± 6 ‰. The Rocknest sand deposit gave a highly uncertain δ37Cl value of - 7 ± 44 ‰. These light and highly variable δ37Cl values are unique among known solar system materials. Two endmember models are offered to account for these observations, and in both, perchlorate, with its extreme ability to fractionate Cl isotopes, is critical. In the first model, SAM is detecting HCl from an oxychlorine compound (e.g., perchlorate) produced from volcanic gas emissions by atmospheric chemical reactions. Similar reactions in Earth's atmosphere may be responsible for the isotopically lightest known Cl outside of this study, in perchlorate from the Atacama Desert. Some of the Gale Crater δ37Cl values are more negative than those in Atacama perchlorate, but because reaction mechanisms and associated fractionation factors are unknown, it is impossible to assess whether this difference is prohibitive. If the negative δ37Cl signal is produced in this fashion, the isotopic variability among samples could arise either from variations in the relative size of the reactant chloride and product perchlorate reservoirs, or from variations in the fraction of perchlorate reduced back to chloride after deposition. Such reduction strongly enriches 37Cl in the residual perchlorate. Perchlorate reduction alone offers an alternative endmember model that can explain the observed data if SAM measured HCl derived

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

    Science.gov (United States)

    Shcherbakova, Viktoria; Oshurkova, Viktoria; Yoshimura, Yoshitaka

    2015-01-01

    The terrestrial permafrost represents a range of possible cryogenic extraterrestrial ecosystems on Earth-like planets without obvious surface ice, such as Mars. The autotrophic and chemolithotrophic psychrotolerant methanogens are more likely than aerobes to function as a model for life forms that may exist in frozen subsurface environments on Mars, which has no free oxygen, inaccessible organic matter, and extremely low amounts of unfrozen water. Our research on the genesis of methane, its content and distribution in permafrost horizons of different ages and origin demonstrated the presence of methane in permanently frozen fine-grained sediments. Earlier, we isolated and described four strains of methanogenic archaea of Methanobacterium and Methanosarcina genera from samples of Pliocene and Holocene permafrost from Eastern Siberia. In this paper we study the effect of sodium and magnesium perchlorates on growth of permafrost and nonpermafrost methanogens, and present evidence that permafrost hydogenotrophic methanogens are more resistant to the chaotropic agent found in Martian soil. In this paper we study the effect of sodium and magnesium perchlorates on the growth of permafrost and nonpermafrost methanogens, and present evidence that permafrost hydogenotrophic methanogens are more resistant to the chaotropic agent found in Martian soil. Furthermore, as shown in the studies strain M2(T) M. arcticum, probably can use perchlorate anion as an electron acceptor in anaerobic methane oxidation. Earth's subzero subsurface environments are the best approximation of environments on Mars, which is most likely to harbor methanogens; thus, a biochemical understanding of these pathways is expected to provide a basis for designing experiments to detect autotrophic methane-producing life forms on Mars. PMID:27682103

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

    Science.gov (United States)

    Shcherbakova, Viktoria; Oshurkova, Viktoria; Yoshimura, Yoshitaka

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Viktoria Shcherbakova

    2015-09-01

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

  9. Formation of oxidizing species via irradiation of perchlorates using high-energy electrons and D 2 + ions

    Science.gov (United States)

    Crandall, Parker B.; Gillis-Davis, Jeffrey J.; Kaiser, Ralf-Ingo

    2016-10-01

    The perchlorate ion (ClO4–) has garnered particular interest in recent years following the discovery of perchlorate salts in the Martian regolith at levels of 0.4–0.6 wt% by the Phoenix lander in 2006 and Mars Science Laboratory's Curiosity rover in 2013. Due to their oxidizing properties, perchlorates are suspected to play a contributing role to the surprising lack of organics on the Martian surface. In this study, magnesium perchlorate hexahydrate (Mg(ClO4)2●6H2O) samples were irradiated with monoenergetic beams of 5 keV electrons and D2+ ions separately, sequentially, and simultaneously to simulate the effects of galactic cosmic ray exposure of perchlorates. The irradiation experiments were carried out under ultra-high vacuum conditions at 50 K, after which the samples were slowly heated to 300 K (0.5 K min–1) while desorbing products were monitored by quadrupole mass spectrometry. In all cases, molecular oxygen (O2) was detected upon the onset of irradiation and again during the warmup phase. In the case of simultaneous irradiation, deuterated water (D2O) and deuterium peroxide (D2O2) were also detected as the sample was heated whereas in the D2+ experiment small amounts of D2O2 was found exclusively. When samples were irradiated sequentially, the production of D2O2 was dependent upon the sample being irradiated with D2+ ions prior to electrons. These experiments show that perchlorates are capable of producing multiple oxidizing agents (O2, D2O2) which may also account for the lack of organics on the Martian surface.

  10. Bis[N-(2-pyridylcarbonylpyridine-2-carboximidato]iron(III perchlorate methanol solvate

    Directory of Open Access Journals (Sweden)

    Dayu Wu

    2009-11-01

    Full Text Available In the title complex, [Fe(C12H8N3O22]ClO4·CH3OH, the iron(III ion is surrounded by two tridentate N-(2-pyridylcarbonylpyridine-2-carboximidate (bpca ligands and exhibits a distorted octahedral coordination by six bpca N atoms. A classical O—H...O hydrogen bond exists between the methanol solvent molecule and the perchlorate anion. Magnetic susceptibility measurements indicated the complex to be in the low-spin state in the temperature range 5–400 K.

  11. Lanthanide perchlorate complexes of quinoline-1-oxide and isoquinoline-2-oxide

    OpenAIRE

    Kalyanasundaram, R; Navaneetham, NS; Soundararajan, S.

    1985-01-01

    Complexes of lanthanide perchlorates with quinoline-1-oxide and isoquinoline-2-oxide have been isolated for the first time characterised by analysis, conductance and IR, NMR and electronic spectoral studies. The complexes of quinoline-1-oxide have the composition $Ln(QNO)_8$$(ClO_4)_3$ where Ln = La, Pr or Nd and $Ln(QNO)_7$ where Ln = Gd, Dy, Ho, Er, Yb. The isoquinoline-2-oxide complexes analyse for the formula $Ln(IsoQNO)_7(ClO_4)_3$ where Ln = La-Yb.

  12. Zero-Pressure Organic Superconductor: Di-(Tetramethyltetraselenafulvalenium)-Perchlorate [(TMTSF)2ClO4

    DEFF Research Database (Denmark)

    Bechgaard, Klaus; da Costa Carneiro, Kim; Olsen, Malte;

    1981-01-01

    Evidence for superconductivity in the organic conductor di-(tetramethyltetraselenafulvalenium)-perchlorate [(TMTSF)2ClO4] has been found by resistance measurements in the absence of applied pressure. For different crystals the transitions are approximately 0.3 K wide and are centered around tempe...... temperatures between 1.2 and 1.4 K. At 0.9 K, a perpendicular magnetic field of 25 mT nearly restores normal resistance. Below 0.1 K, this critical field exceeds 50 mT....

  13. Purification of human genomic DNA from whole blood using sodium perchlorate in place of phenol.

    Science.gov (United States)

    Johns, M B; Paulus-Thomas, J E

    1989-08-01

    We have developed a new, rapid method for the extraction of human genomic DNA from whole blood samples. Traditionally, genomic DNA has been extracted from blood by overnight proteinase K digestion of lysed peripheral lymphocytes followed by phenol/chloroform extraction. In addition to being time consuming, the use of phenol involves inherent risks due to the toxic nature of the reagent. Our method for the extraction of DNA from whole blood uses sodium perchlorate and chloroform instead of phenol with a significant time savings realized as well as fewer hazards to the technician. Furthermore, DNA prepared by this new method is an excellent substrate for restriction endonuclease digestion and Southern hybridization analysis.

  14. Reanalysis of the Viking results suggests perchlorate and organics at mid-latitudes on Mars

    Science.gov (United States)

    Navarro-Gonzalez, R.; Vargas, E.; de La Rosa, J.; Raga, A. C.; McKay, C.

    2010-12-01

    The most comprehensive search for organics in the Martian soil was performed by the Viking Landers. Martian soil was subjected to a thermal volatilization process in order to vaporize and break organic molecules, and the resultant gases and volatiles were analyzed by gas chromatography-mass spectrometry. Only water at 0.1-1.0 wt% was detected with traces of chloromethane at 15 ppb in the Viking Landing site 1, and water at 0.05-1.0 wt% and carbon dioxide at 50-700 ppm with traces of dichloromethane at 0.04-40 ppb in the Viking Landing site 2. The abundance ratio of the 35Cl and 37Cl isotopes in these chlorohydrocarbons was 3:1, corresponding to the terrestrial isotopic abundance. Therefore, these chlorohydrocarbons were considered to be terrestrial contaminants although they had not been detected at those levels in the blank runs. Recently, perchlorate was discovered in the Martian Arctic soil by the Phoenix Lander. Here we show that when Mars-like soils from the Atacama Desert with 32±6 ppm of organic carbon are mixed with 1 wt% magnesium perchlorate and heated nearly all the organics present are decomposed to water and carbon dioxide, but a small amount are chlorinated forming 1.6 ppm of chloromethane and 0.02 ppm of dichloromethane at 500○C. A chemical kinetics model was developed to predict the degree of oxidation and chlorination of organics in the Viking oven. The isotopic distribution of 35Cl and 37Cl for Mars is not known. Studies on Earth indicate that there is no isotopic fractionation of chlorine in the mantle or crust, despite the fact that it is significantly depleted on the planet as compare to solar abundances. The 37Cl/35Cl isotopic ratio in carbonaceous chondrites is similar to the Earth’s value, which suggests that the terrestrial planets, including Mars, were all formed from a similar reservoir of chlorine species in the presolar nebulae and that there was no further isotopic fractionation during the Earth’s differentiation or late

  15. 2-(2-Hydroxy-3-methoxyphenyl-1H-benzimidazol-3-ium perchlorate

    Directory of Open Access Journals (Sweden)

    Chuan Chen

    2012-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-05-15

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

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

    International Nuclear Information System (INIS)

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

  18. Hydration Structure of the Quaternary Ammonium Cations

    KAUST Repository

    Babiaczyk, Wojtek Iwo

    2010-11-25

    Two indicators of the hydropathicity of small solutes are introduced and tested by molecular dynamics simulations. These indicators are defined as probabilities of the orientation of water molecules\\' dipoles and hydrogen bond vectors, conditional on a generalized distance from the solute suitable for arbitrarily shaped molecules. Using conditional probabilities, it is possible to distinguish features of the distributions in close proximity of the solute. These regions contain the most significant information on the hydration structure but cannot be adequately represented by using, as is usually done, joint distance-angle probability densities. Our calculations show that using our indicators a relative hydropathicity scale for the interesting test set of the quaternary ammonium cations can be roughly determined. © 2010 American Chemical Society.

  19. Racer (Ammonium Nonanoate) weed control evaluation for onions

    Science.gov (United States)

    Racer has been labeled as a herbicide for food use and is currently under consideration as an organic herbicide for organically grown food crops. The main component (40%) of Racer is ammonium nonanoate (ammonium pelargonate), which occurs in nature and primarily formed from biodegradation of higher...

  20. Ammonium and hydroxylamine uptake and accumulation in Nitrosomonas

    NARCIS (Netherlands)

    Schmidt, I.; Look, C.; Bock, E.; Jetten, M.S.M.

    2004-01-01

    Starved cells of Nitrosomonas europaea and further ammonia oxidizers were able to rapidly accumulate ammonium and hydroxylamine to an internal concentration of about 1 and 0.8 M, respectively. In kinetic studies, the uptake/accumulation rates for ammonium [3.1 mmol (g protein)(-1) min(-1)] and hydro

  1. How to make a living from anaerobic ammonium oxidation

    NARCIS (Netherlands)

    Kartal, B.; De Almeida, N.M.; Maalcke, W.J.; Op den Camp, H.J.M.; Jetten, M.S.M.; Keltjens, J.T.

    2013-01-01

    Anaerobic ammonium-oxidizing (anammox) bacteria primarily grow by the oxidation of ammonium coupled to nitrite reduction, using CO2 as the sole carbon source. Although they were neglected for a long time, anammox bacteria are encountered in an enormous species (micro)diversity in virtually any anoxi

  2. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Science.gov (United States)

    2010-04-01

    ... HUMAN CONSUMPTION Food Preservatives § 172.165 Quaternary ammonium chloride combination. The food... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Quaternary ammonium chloride combination. 172.165 Section 172.165 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN...

  3. Seasonal patterns of ammonium regeneration from size-fractionated microheterotrophs

    Science.gov (United States)

    Maguer, Jean-François; L'Helguen, Stéphane; Madec, Christian; Le Corre, Pierre

    1999-11-01

    Ammonium regeneration by size-fractionated plankton was measured for 1 year at a coastal station in the shallow well-mixed waters of the western English Channel. Rates of ammonium regeneration in the Journal of Plankton Research, 18, 355-370). Total ammonium regenerated in a year by the microheterotrophs was 15 g N m -2, equivalent to about 60% of the total nitrogen uptake. Microplankton (200-15 μm) accounted for about 50% of the regeneration measured between early spring and late summer. Percent contribution of nanoplankton to total ammonium regeneration varied considerably between the seasons, from very high (83-88%) levels in winter to very low (2-13%) levels in summer. Contribution by picoplankton (nano- and picoplankton fractions, appears to be different from that in deep well-mixed waters. Here, the relative contribution of ciliates and bacteria to ammonium regeneration shows little variation with an increase in macrozooplankton biomass.

  4. Adsorption of Chloride,Nitrate and Perchlorate by Variable Charge Soils

    Institute of Scientific and Technical Information of China (English)

    JIGUO-LIANG; KONGXIAO-LING

    1992-01-01

    Two cells consisting of a chloride-selective eloectrode and a nitrate-selective electrode or of a chloride-selectrive electrode and a perchlorate-selective electrode were directly put in the soil suspension to determine the concentration rations Cl-/NO3- or Cl-/ClO4- for studying the adsorption of the three anions by variable charge soils.It was found that all the concentration ration CCl-/CNO3- and CCl-/CClO4- in suspension were smaller than unity when soil samples were in equilibrium with mixed KCl and KNO3 or KCl and KClO4 solutions of equal concentration.The order of the amount of chloride,nitrate and perchlorate adsorbed by variable charge soils was Cl->NO3->ClO4- when the soils adsorbed these anions from the solution containing equal concentrations of Cl-,NO3- and ClO4-.Such factors as the pH of the suspension,the iron oxide content of the soil etc.Could affect the amounts and the ratios of anions adsorbed.The adsorption was chiefly caused by coulombic attraction,but a covalent force between the anion and the metal atom on the surface of soil particles may also be involved,at least for Cl- ions,even for NO3- ions.

  5. 123Iodine scintigraphy and perchlorate discharge test in the diagnosis of congenital hypothyroidism

    International Nuclear Information System (INIS)

    Aim: Thirty eight children suffering from congenital primary permanent hypothyroidism were studied to determine the diagnostic impact of 123I scintigraphy in comparison to laboratory findings and ultrasonography. Methods: In all patients 123I scintigraphy was performed after intravenous administration of 3,7 MBq 123I. If accumulation of the radiotracer in thyroid tissue occured a perchlorate discharge test was performed subsequently. Results: Scintigraphy revealed athyrosis in 7 children. In 9 children a lingual thyroid was observed. Deficiency in iodine organification was diagnosed by a significant discharge of 123I in 15 patients. In four of these children the diagnosis of Pendred's syndrome could be established. Ectopic thyroid tissue could be demonstrated only by scintigraphy where clinical examination and sonography failed in the diagnosis in all cases. Hypoplasia of the thyroid gland as it was diagnosed in 2 cases by ultrasonography appeared to be unlikely because of normal 123I uptake was seen in these patients. In 2 patients with scintigraphic proven athyrosis an orthotopic gland had been falsely considered by ultrasound. In 44% of our patients the final diagnosis could only be established if 123I scintigraphy and perchlorate discharge test were performed. Conclusion: This findings suggest that scintigraphy is indispensible in the correct diagnostic work up of congenital hypothyroidism. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-04-14

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

  7. Anomalous aryl strengthening of americium and europium complexes during extraction by alkylenediphosphine dioxides from perchloric acid media

    International Nuclear Information System (INIS)

    Extraction of americium and europium from perchlorate environments by solutions of three types of methylenediphosphine dioxides, namely (C6H5)P(O)(CH2)sub(n)(O)P(C6H5)2, (C6H5)2P(O)CH2(O)P(C8H17)2 and (C8H17)2P(O)(CH2)sub(n)(O)P(C8H17)2 has been studied (n is 1 or 2 ) The diluents used have been dichlorethane and chloroform. In perchlorate environments the distribuiton coefficients of americium and europium have proved to be by about 3 orders of magnitude higher than in nitric acid environments, i.e. in perchlorate media the complexes are far more stable. Separation coefficients of americium and REE in perchloric acid soutions are much higher than in nitrate environments. The average value of Am/Eu separation coeffecient at 1-5 M acidity was about 6 (with dichlorethane as diluent) or about 7 (with chloroform as diluent). The complexes essentially exist as trisolvated. Americium complexes display anomalous stability increase upon being diluted: by about 2 orders of magnitude with dichlorethane and by up to 3 orders of magnitude with chloroform used as diluent

  8. Reversible, Selective Trapping of Perchlorate from Water in Record Capacity by a Cationic Metal-Organic Framework.

    Science.gov (United States)

    Colinas, Ian R; Silva, Rachel C; Oliver, Scott R J

    2016-02-16

    We report the capture of ppm-level aqueous perchlorate in record capacity and kinetics via the complete anion exchange of a cationic metal-organic framework. Ambient conditions were used for both the synthesis of silver 4,4'-bipyridine nitrate (SBN) and the exchange, forming silver 4,4'-bipyridine perchlorate (SBP). The exchange was complete within 90 min, and the capacity was 354 mg/g, representing 99% removal. These values are greater than current anion exchangers such as the resins Amberlite IRA-400 (249 mg/g), Purolite A530E (104 mg/g), and layered double hydroxides (28 mg/g). Moreover, unlike resins and layered double hydroxides, SBN is fully reusable and displays 96% regeneration to SBN in nitrate solution, with new crystal formation allowing the indefinite cycling for perchlorate. We show seven cycles as proof of concept. Perchlorate contamination of water represents a serious health threat because it is a thyroid endocrine disruptor. This noncomplexing anionic pollutant is significantly mobile and environmentally persistent. Removal of other anionic pollutants from water such as chromate, pertechnetate, or arsenate may be possible by this methodology. PMID:26765213

  9. Population of Nitrifying Bacteria and Nitrification in Ammonium Saturated Clinoptilolite

    Science.gov (United States)

    McGilloway, R. L.; Weaver, R. W.; Ming, Douglas W.; Gruener, J.

    1999-01-01

    As humans begin to spend longer periods of time in space, plants will be incorporated into life support systems. Ammonium saturated clinoptilolite is one plant growth substrate but a balance between ammonium and nitrate is needed. A laboratory study was conducted to determine effects of nitrifying bacteria on ammonium concentrations and kinetics of nitrification. Columns containing clinoptilolite substrate amended with nitrifying bacteria obtained from soil enrichment were analyzed weekly for a 90 day period. The enrichment culture initially contained 1 x 10(exp 5) ammonium oxidizing bacteria and 1 x 10(exp 2) nitrite oxidizing bacteria per gram of substrate. Populations of ammonium oxidizing bacteria increased to 1 x 10(exp 6) and nitrite oxidizing bacteria increased to 1 x 10(exp 3) per gram of substrate. The nitrification rate was approximately 0.25mg NO3(-)-N/kg.hr. Experiments were also conducted to enumerate nitrifying bacteria in a clinoptilolite substrate used to grow wheat (Triticum aestivum L.). Seventy days following the initial inoculation with an unknown number of commercial nitrifying bacteria, 1 x 10(exp 5) ammonium oxidizing bacteria per gram of substrate were present. The number of nitrite oxidizing bacteria was between 1 x 10(exp 3) to 10(exp 4) per gram of substrate as measured by the most probable number method. Nitrification rates were approximately 0.20mg NO3(-)-N/kg.hr. Clinoptilolite readily exchanged sufficient concentrations of ammonium to support nitrifying bacteria and they survived well in this medium.

  10. Modelling an Ammonium Transporter with SCLS

    Directory of Open Access Journals (Sweden)

    Angelo Troina

    2009-10-01

    Full Text Available The Stochastic Calculus of Looping Sequences (SCLS is a recently proposed modelling language for the representation and simulation of biological systems behaviour. It has been designed with the aim of combining the simplicity of notation of rewrite systems with the advantage of compositionality. It also allows a rather simple and accurate description of biological membranes and their interactions with the environment.In this work we apply SCLS to model a newly discovered ammonium transporter. This transporter is believed to play a fundamental role for plant mineral acquisition, which takes place in the arbuscular mycorrhiza, the most wide-spread plant-fungus symbiosis on earth. Due to its potential application in agriculture this kind of symbiosis is one of the main focuses of the BioBITs project. In our experiments the passage of NH3 / NH4+ from the fungus to the plant has been dissected in known and hypothetical mechanisms; with the model so far we have been able to simulate the behaviour of the system under different conditions. Our simulations confirmed some of the latest experimental results about the LjAMT2;2 transporter. The initial simulation results of the modelling of the symbiosis process are promising and indicate new directions for biological investigations.

  11. New quaternary ammonium salts based decontaminants

    Directory of Open Access Journals (Sweden)

    Diana M. Popescu

    2014-06-01

    Full Text Available Decontamination after terrorist attacks or industrial accidents with biological and/or chemical agents („bio-chem“ must be fast and efficient, in order to reduce the number of victims and to eliminate the consequent damages. The decontamination of living biological agents (bacteria, viruses or nonliving ones (toxins, regulators and toxic chemicals could be accomplished by reactions of hydrolysis in various experimental conditions, in particular in alkaline medium, reactions with amines or ammonia, alcohols, phenols etc. and by their transformation into less toxic degradation products. “Bio-chem” intentional or unintentional contamination is a real risk, towards which an effective management must be available to prevent and control it. Decontamination is an essential measure to protect the personnel and the environment. Synthesis and testing of new „bio-chem“ decontaminants, based on quaternary ammonium salts, complete the arsenal of protection against chemical and biological agents. The most effective selected substances could be produced and used for decontamination in accordance with legal procedures

  12. Correlation of anaerobic ammonium oxidation and denitrification

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The feasibility of the nitrous organic wastewater treated was studied in seven anaerobic sequencing batch reactors(ASBRs)(0 #-6 #) which had been run under stable anaerobic ammonium oxidation (Anammox). By means of monitoring and data analysis of COD, NH4+-N, NO2--N, NO3--N and pH, and of microbial test, the results revealed that the optimal Anammox performance was achieved from 2# reactor in which COD/NH4+-N was 1.65, Anammox bacteria and denitrification bacteria could coexist, and Anammox reaction and denitrification reaction could occur simultaneously in the reactors. The ratio of NH4+-N consumed: NO2--N consumed: NO3--N produced was 1:1.38:0.19 in 0# reactor which was not added glucose in the wastewater. When different ratio of COD and NH4+-N was fed for the reactors, the ratio of NO2--N consumed: NH4+-N consumed was in the range of 1.51-2.29 and the ratio of NO3-N produced: NH4+-N consumed in the range of 0-0.05.

  13. Influence of the Different Level Ammonium on NRA and GSA in Sugar Beet(Vulgaris L.)

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Ammonium nitrogen inhibited NR activity in sugar beet,NR activity was lower in endogenous substrate after ammonium nitrogen was used,and the correlation between NR activity and ammonium nitrogen levels was negative.But NR activity raised with the ammonium nitrogen levels raising in exogenous.Ammonium nitrogen prompted GS activity:the correlation between GS activity and ammonium nitrogen was positive,GS activity raised with ammonium nitrogen levels raising,GS activity of roots and leaves had same change trend in sugar beet in the whole growth duration after ammonium nitrogen was used,but GS activity in roots was higher than that in leaves.

  14. Effect of Ammonium Nitrate on Nanoparticle Size Reduction

    Directory of Open Access Journals (Sweden)

    Kalyana C. Pingali

    2008-01-01

    Full Text Available Ammonium nitrate was added to the spraying solution as a foaming agent to reduce the particle size of nanoparticles synthesized in the spray-pyrolysis process. Ammonium nitrate was effective in breaking the aerosol droplet size and generating nanoparticles that were of approximately one order-of-magnitude (from 200 to 20 nm smaller diameter than those created in the absence of ammonium nitrate in the feed solution. This technique makes it possible to control the particle diameter of metallic nanoparticles below 20 nm.

  15. Perchlorate and selected metals in water and soil within Mount Rushmore National Memorial, South Dakota, 2011–15

    Science.gov (United States)

    Hoogestraat, Galen K.; Rowe, Barbara L.

    2016-04-14

    Mount Rushmore National Memorial is located in the east-central part of the Black Hills area of South Dakota and is challenged to provide drinking water to about 3 million annual visitors and year-round park personnel. An environmental concern to water resources within Mount Rushmore National Memorial has been the annual aerial fireworks display at the memorial for the Independence Day holiday during 1998–2009. A major concern of park management is the contamination of groundwater and surface water by perchlorate, which is used as an oxidizing agent in firework displays. A study by the U.S. Geological Survey, in cooperation with the National Park Service, was completed to characterize the occurrence of perchlorate and selected metals (constituents commonly associated with fireworks) in groundwater and surface water within and adjacent to Mount Rushmore National Memorial during 2011–15. Concentrations of perchlorate and metals in 106 water samples (collected from 6 groundwater sites and 14 surface-water sites) and 11 soil samples (collected from 11 soil sites) are reported.Within the Mount Rushmore National Memorial boundary, perchlorate concentrations were greatest in the Lafferty Gulch drainage basin, ranging from less than 0.20 to 38 micrograms per liter (μg/L) in groundwater samples and from 2.2 to 54 μg/L in surface-water samples. Sites within the Starling Gulch drainage basin also had some evidence of perchlorate contamination, with concentrations ranging from 0.61 to 19 μg/L. All groundwater and surface-water samples within the unnamed tributary to Grizzly Bear Creek drainage basin and reference sites outside the park boundary had concentrations less than 0.20 μg/L. Perchlorate concentrations in samples collected at the 200-foot-deep production well (Well 1) ranged from 17 to 38 μg/L with a median of 23 μg/L, whereas perchlorate concentrations in samples from the 500-foot-deep production well (Well 2) ranged from 2.1 to 17 μg/L, with a median of 6

  16. {sup 14}N NQR and relaxation in ammonium nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Stephenson, David, E-mail: david.stephenson@sta.uwi.edu [University of the West Indies, Chemistry Department (Trinidad and Tobago)

    2015-04-15

    The complete {sup 14}N nuclear quadrupole resonance (NQR) spectrum of ammonium nitrate is presented recorded using two double resonance techniques – double contact cross relaxation and zero field NQR. The spectra gave the quadrupole coupling constant (Qcc) and asymmetry parameter (η) values for the nitro of 611 kHz, 0.229 and that for the ammonium nitrogen of 242 kHz, 0.835. The three relaxation transition probabilities have been determined for both the nitro and ammonium nitrogen atoms. The bi-exponential relaxation times (T {sub 1}) were measured at 295 K. The values for nitro are 16.9 s and 10.5 s and that of the ammonium are 23.0 s and 16.4 s.

  17. Ammonium removal by modified zeolite from municipal wastewater

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ya-ping; GAO Ting-yao; JIANG Shang-ying; CAO Da-wen

    2004-01-01

    Ammonium removal by modified zeolite, H-form and Na-form zeolite, were examined by batch-type methods. The adsorption of ammonium on modified zeolite was exothermic process. The saturation adsorption capacity of ammonium on H-form and Na-form zeolite were 21.23 and 41.15 mg/g, respectively. After ten times adsorption- desorption-readsorption cycles the standard deviations of H-form and Na-form zeolite were 6.34% and 6.59%. The zeolite adsorption process has proved cost effective and practical in reducing ammonium by H-form and Na-form zeolite in municipal wastewater from concentration 27.68 mg/L to 2.80 mg/L and 5.91 mg/L.

  18. Fixed Ammonium Content and Maximum Capacity of Ammonium Fixation in Major Types of Tillage Soils in Hunan Province, China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yang-zhu; HUANG Shun-hong; WAN Da-juan; HUANG Yun-xiang; ZHOU Wei-jun; ZOU Ying-bin

    2007-01-01

    In order to understand the status of fixed ammonium, fixed ammonium content, maximum capacity of ammonium fixation, and their influencing factors in major types of tillage soils of Hunan Province, China, were studied with sampling on fields, and laboratory incubation and determination. The main results are summarized as follows: (1) Content of fixed ammonium in the tested soils varies greatly with soil use pattern and the nature of parent material. For the paddy soils, it ranges from 135.4 ± 57.4 to 412.8±32.4 mg kg-1, with 304.7±96.7 mg kg-1 in average; while it ranges from 59.4 to 435.7 mg kg-1, with 230.1 ± 89.2 mg kg1 in average for the upland soils. The soils developed from limnic material and slate had higher fixed ammonium content than the soils developed from granite. The percentage of fixed ammonium to total N in the upland soils is always higher than that in the paddy soils. It ranges from 6.1 ± 3.6% to 16.6 ±4.6%, with 14.0% ± 5.1% in average for the paddy soils and it amounted to 5.8 ±2.0% to 40.1 ± 17.8%, with 23.5 ± 14.2% in average for upland soils. (2) The maximum capacity of ammonium fixation has the same trend with the fixed ammonium content in the tested soils. For all the tested soils, the percentage of recently fixed ammonium to maximum capacity of ammonium fixation is always bellow 20% and it may be due to the fact that the soils have high fertility and high saturation of ammonium-fixing site. (3) The clay content and clay composition in the tested soils are the two important factors influe ncing their fixed ammonium content and maximum capacity of ammonium fixation. The results showed that hydrous mica is the main 2:1 type clay mineral in <0.02 mm clay of the paddy soils, and its content in 0.02-0.002 mm clay is much higher than that in < 0.002 mm clay of the soils. The statistical analysis showed that both the fixed ammonium content and the maximum capacity of ammonium fixation of the paddy soils were positively correlated with

  19. Thyroid scintigraphy and perchlorate discharge test in the diagnosis of congenital hypothyroidism

    Energy Technology Data Exchange (ETDEWEB)

    El-Desouki, M. [Dept. of Medicine, King Saud Univ., Riyadh (Saudi Arabia); Al-Jurayyan, N. [Dept. of Paediatrics, King Saud Univ., Riyadh (Saudi Arabia); Al-Nuaim, A. [Div. of Endocrinology, King Saud Univ., Riyadh (Saudi Arabia); Al-Herbish, A. [Dept. of Paediatrics, King Saud Univ., Riyadh (Saudi Arabia); Abo-Bakr, A. [Dept. of Paediatrics, King Saud Univ., Riyadh (Saudi Arabia); Al-Mazrou, Y. [Ministry of Health, Riyadh (Saudi Arabia); Al-Swailem, A. [Ministry of Health, Riyadh (Saudi Arabia)

    1995-09-01

    Quantitative thyroid scanning using low doses of technetium-99m sodium pertechnetate was performed on 147 infants (55 males and 92 females) with congenital hypothyroidism detected through the national neonatal screening programme. Thirty-two (21.8%) were athyrotic, while 62 (42.2%) had an ectopic thyroid and 53 (36%) had a eutopic gland with increased {sup 99m}Tc uptake (mean 17%; range, 5%-38%). The perchlorate discharge test (PDT) was performed in nine of the infants with ectopic glands and 15 with eutopic glands; the findings were consistent with an organification defect in 22 cases (seven ectopic and 15 eutopic). Thyroid scintigraphy and PDT can add useful aetiological, genetic and prognostic information in the clinical evaluation of infants with congenital hypothyroidism detected by neonatal screening. (orig.). With 4 figs., 1 tab.

  20. Large Angular Jump Mechanism Observed for Hydrogen Bond Exchange in Aqueous Perchlorate Solution

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Minbiao; /SLAC, PULSE /Stanford U., Phys. Dept.; Odelius3, Michael; /Stockholm U.; Gaffney1, K.J.; /aff SLAC, PULSE

    2010-06-11

    The mechanism for hydrogen bond (H-bond) switching in solution has remained subject to debate despite extensive experimental and theoretical studies. We have applied polarization-selective multidimensional vibrational spectroscopy to investigate the H-bond exchange mechanism in aqueous NaClO{sub 4} solution. The results show that a water molecule shifts its donated H-bonds between water and perchlorate acceptors by means of large, prompt angular rotation. Using a jump-exchange kinetic model, we extract an average jump angle of 49 {+-} 4{sup o}, in qualitative agreement with the jump angle observed in molecular dynamics simulations of the same aqueous NaClO{sub 4} solution.

  1. Effect of Microwave Heating on the Leaching of Lateritic Nickel Ore in Perchloric Acid

    International Nuclear Information System (INIS)

    In this study, the leaching conditions of Sivrihisar (Adatepe) limonite type lateritic ore in acidic medium were investigated. Leaching experiments were carried out using conventional and microwave-assisted method. The effects of stirring speed, leaching temperature, perchloric acid concentration, solid/liquid ratio and particle size on conventional leaching were determined. Microwave-assisted leaching was carried out by using the optimum results of the conventional leaching. The pre-heating process was applied on different microwave powers (0, 90, 180, 360 and 600 W) and pre-processing time (0, 1, 3, 5, 7, 10, 15 and 20 min). These experimental results demonstrated that acid leaching was a convenient method for Ni extraction from lateritic ore. The higher dissolution and the higher Ni recoveries in the microwave-assisted leaching process were obtained in less leach time. (author)

  2. Thyroid scintigraphy and perchlorate discharge test in the diagnosis of congenital hypothyroidism

    International Nuclear Information System (INIS)

    Quantitative thyroid scanning using low doses of technetium-99m sodium pertechnetate was performed on 147 infants (55 males and 92 females) with congenital hypothyroidism detected through the national neonatal screening programme. Thirty-two (21.8%) were athyrotic, while 62 (42.2%) had an ectopic thyroid and 53 (36%) had a eutopic gland with increased 99mTc uptake (mean 17%; range, 5%-38%). The perchlorate discharge test (PDT) was performed in nine of the infants with ectopic glands and 15 with eutopic glands; the findings were consistent with an organification defect in 22 cases (seven ectopic and 15 eutopic). Thyroid scintigraphy and PDT can add useful aetiological, genetic and prognostic information in the clinical evaluation of infants with congenital hypothyroidism detected by neonatal screening. (orig.). With 4 figs., 1 tab

  3. Potentiometric Electronic Tongue to Resolve Mixtures of Sulfide and Perchlorate Anions

    Directory of Open Access Journals (Sweden)

    Deivy Wilson

    2011-03-01

    Full Text Available This work describes the use of an array of potentiometric sensors and an artificial neural network response model to determine perchlorate and sulfide ions in polluted waters, by what is known as an electronic tongue. Sensors used have been all-solid-state PVC membrane selective electrodes, where their ionophores were different metal-phtalocyanine complexes with specific and anion generic responses. The study case illustrates the potential use of electronic tongues in the quantification of mixtures when interfering effects need to be counterbalanced: relative errors in determination of individual ions can be decreased typically from 25% to less than 5%, if compared to the use of a single proposed ion-selective electrode.

  4. Hydration of some trivalent metal ions extracted as perchlorates with trioctylphosphine oxide in hexane

    International Nuclear Information System (INIS)

    Perchlorates of Sc3+, Y3+, La3+, and Eu3+ have each been extracted from 0.1 mol x dem-3 aqueous solution of μ=1 with trioctylphosphine oxide (TOPO) in hexane. The hydration number of the extracted salts has been determined by Karl Fischer titration. Sc3+, Y3+, and Eu3+ are extracted as the tetra- and hexa-solvates of TOPO but the assumption of octa-solvate on addition to the tetra-solvate explains the extraction data of La3+ well. The hydration number of tetra-solvates is 2(Sc3+ and Eu3+), 3(Y3+) and probably 4 for La3+ ion. That of hexa-and octa-solvates is 4-5. (author)

  5. Hydration and Solvation of Metal Perchlorates Extracted with Trioctylphosphine Oxide in Hexane

    International Nuclear Information System (INIS)

    Perchlorates of Sc3+, Y3+, La3+, and Eu3+ have each been extracted from 0.1 mol dm-3 aqueous solution of μ=1 with trioctylphosphine oxide (TOPO) in hexane. The hydration number of the extracted salts has been determined by Karl Fischer titration. Sc3+, Y3+, and Eu3+ are extracted as the tetra- and hexa-solvates of TOPO but the assumption of octa-solvate on addition to the tetra-solvate explains the extraction data of La3+ well. The hydration number of tetra-solvates is 2 (Sc3+ and Eu3+), 3 (Y3+) and probably 4 for La3+ ion. That of hexa-and octa- solvates is 4-5. (author). 1 tabs

  6. Complexes of rare-earth perchlorates with ditbutyl amides of di, tri and tetraglycolic acids

    OpenAIRE

    Premlatha, C; Soundararajan, S

    1981-01-01

    New complexes of lanthanide perchlorates with di-t-butyl amides of di, tri and tetraglycolic acids have been synthesised. The complexes have the general formula Ln(DiGA)3(ClO4)3; Ln(TriGA)2 (ClO4)3 and Ln(TetGA)2 (C1O4)3, where Ln = La-Yb and Y and DiGA = N,N′, di-t-butyl diglycolamide, TriGA N,N′, di-t-butyl triglycolamide and TetGA = N,N′ di-t-butyl tetraglycolamide, respectively. The complexes have been characterized by analysis, electrolytic conductance, infrared,1H and13C nuclear magneti...

  7. Application of Probabilistic Risk Assessment in Establishing Perchlorate and Goitrogen Risk Mitigation Strategies.

    Science.gov (United States)

    Crawford-Brown, Douglas

    2015-09-01

    This paper applies probabilistic risk assessment in quantifying risks from cumulative and aggregate risk pathways for selected goitrogens in water and food. Results show that the percentages of individuals with a Hazard Index (HI) value above 1 ranges between 30% and 50% both with and without serum half-life correction when a traditional regulatory assessment approach based on establishment of a No Observed Effects Level (NOEL) is used. When an exposure-response curve is instead used and a threshold of 50% inhibition is assumed, 1.1% or less of the population exceeds an HI value of 1 with no serum half-life correction, rising to as high as 11% when serum half-life correction is applied. If 0% to 5% threshold for iodide uptake inhibition is assumed for production of adverse effects, the percentage of the population with an HI above 1 is 46.2% or less with no serum half-life correction, and 47.2% or less when serum half-life correction is applied. The probabilistic analysis shows that while there are exposed groups for whom perchlorate exposures are the primary cause of individuals having HI values above 1, these constitute significantly less than 1% of the population. Instead, the potential risk from exposure to goitrogens is dominated by nitrates without serum half-life correction and thiocyanates with serum half-life correction, suggesting public health protection is better accomplished by a focus on these and other goitrogens expect in highly limited cases where waterborne perchlorate is at unusually high concentrations. PMID:26322488

  8. Synthesis, characterization, and bioactivity of rosin quaternary ammonium salt derivatives

    Directory of Open Access Journals (Sweden)

    Tao Liang

    2013-02-01

    Full Text Available Two series of rosin quaternary ammonium salts (QAS were synthesized using the same path. The structure of the target products was characterized by HPLC, MS, IR, and 1HNMR, and the bioactivity was determined by filter paper method using Trametes versicolor (white-rot fungus and Gloeophyllum trabeum (brown-rot fungus, which are two kinds of general wood decay fungi in nature. The results showed that all compounds tested had a satisfactory anti-fungal effect at the molarity of 0.025 mmol/mL. Hereinto, acrylpimaric Gemini QAS had better bioactivity than dehydrogenated or tetrahydrogenated rosin QAS against Trametes versicolor. To this fungus, quaternary ammonium groups, which wraps up the membrane of microorganism and disrupts the balance in cell membrane, plays the leading role for its bioactivity. To Gloeophyllum trabeum, the inhibition activity of acrylpimaric QAS and dehydrogenated rosin QAS are almost at the same level and larger than tetrahydrogenated rosin QAS, so we conclude that both quaternary ammonium group and aromatic group play important roles. Compared with dodecyl dimethyl benzyl ammonium chloride (1227, which is a commercially available quaternary ammonium salt type fungicide, acrylpimaric acid quaternary ammonium salts have approximate bioactivity against Gloeophyllum trabeum. In conclusion, rosin derivatives with functional groups would do well in wood preservative applications.

  9. Mutagenicity of quaternary ammonium salts containing carbohydrate moieties

    Energy Technology Data Exchange (ETDEWEB)

    Dmochowska, Barbara [Department of Carbohydrate Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Piosik, Jacek; Woziwodzka, Anna [Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Kladki 24, 80-822 Gdansk (Poland); Sikora, Karol; Wisniewski, Andrzej [Department of Carbohydrate Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Wegrzyn, Grzegorz, E-mail: wegrzyn@biotech.univ.gda.pl [Department of Molecular Biology, University of Gdansk, Kladki 24, 80-822 Gdansk (Poland)

    2011-10-15

    Highlights: {yields} A series of quaternary ammonium salts containing carbohydrate moieties, with configuration D-galacto, D-gluco and D-manno, was synthesized and characterized. {yields} The quaternary ammonium salts containing carbohydrate moieties revealed potent mutagenic activities, as assessed by using the Vibrio harveyi bioluminescence mutagenicity test. {yields} The N-[2-(D-glycopyranosyloxy)ethyl]-N,N,N-trimethylaminium salts were of the highest activity in the mutagenicity assay. {yields} We suggest that quaternary ammonium salts may be more hazardous than previously supposed. - Abstract: Quaternary ammonium salts are widely used in industrial, agricultural, healthcare and domestic applications. They are believed to be safe compounds, with little or no health hazard to humans. However, in this report, we demonstrate that a series of newly synthesized quaternary ammonium salts containing carbohydrate moieties reveal potent mutagenic activities, as assessed by using the Vibrio harveyi bioluminescence mutagenicity test. D-Gluco- and D-galacto-derivatives were found to have a higher mutagenic potential than D-manno-derivatives. Among the former groups of compounds, the N-[2-(D-glycopyranosyloxy)ethyl]-N,N,N-trimethylaminium salts were of the highest activity in the mutagenicity assay. These results suggest that the safety of quaternary ammonium salts may be lower than previously supposed, indicating a need for testing such compounds for their mutagenicity.

  10. Removal of ammonium from municipal landfill leachate using natural zeolites.

    Science.gov (United States)

    Ye, Zhihong; Wang, Jiawen; Sun, Lingyu; Zhang, Daobin; Zhang, Hui

    2015-01-01

    Ammonium ion-exchange performance of the natural zeolite was investigated in both batch and column studies. The effects of zeolite dosage, contact time, stirring speed and pH on ammonium removal were investigated in batch experiments. The result showed that ammonium removal efficiency increased with an increase in zeolite dosage from 25 to 150 g/L, and an increase in stirring speed from 200 to 250 r/min. But further increase in zeolite dosage and stirring speed would result in an unpronounced increase of ammonium removal. The optimal pH for the removal of ammonium was found as 7.1. In the column studies, the effect of flow rate was investigated, and the total ammonium removal percentage during 180 min operation time decreased with the flow rate though the ion-exchange capacity varied to a very small extent with the flow rate ranging from 4 to 9 mL/min. The spent zeolite was regenerated by sodium chloride solution and the ammonia removal capacity of zeolite changed little or even increased after three regeneration cycles. PMID:26510611

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

    Science.gov (United States)

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

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

    Science.gov (United States)

    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 (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.

  13. Mechanism and kinetics for ammonium dinitramide (ADN) sublimation: a first-principles study.

    Science.gov (United States)

    Zhu, R S; Chen, Hui-Lung; Lin, M C

    2012-11-01

    The mechanism for sublimation of NH(4)N(NO(2))(2) (ADN) has been investigated quantum-mechanically with generalized gradient approximation plane-wave density functional theory calculations; the solid surface is represented by a slab model and the periodic boundary conditions are applied. The calculated lattice constants for the bulk ADN, which were found to consist of NH(4)(+)[ON(O)NNO(2)](-) units, instead of NH(4)(+)[N(NO(2))(2)](-), agree quite well with experimental values. Results show that three steps are involved in the sublimation/decomposition of ADN. The first step is the relaxation of the surface layer with 1.6 kcal/mol energy per NH(4)ON(O)NNO(2) unit; the second step is the sublimation of the surface layer to form a molecular [NH(3)]-[HON(O)NNO(2)] complex with a 29.4 kcal/mol sublimation energy, consistent with the experimental observation of Korobeinichev et al. (10) The last step is the dissociation of the [H(3)N]-[HON(O)NNO(2)] complex to give NH(3) and HON(O)NNO(2) with the dissociation energy of 13.9 kcal/mol. Direct formation of NO(2) (g) from solid ADN costs a much higher energy, 58.3 kcal/mol. Our calculated total sublimation enthalpy for ADN(s) → NH(3)(g) + HON(O)NNO(2)) (g), 44.9 kcal/mol via three steps, is in good agreement with the value, 42.1 kcal/mol predicted for the one-step sublimation process in this work and the value 44.0 kcal/mol computed by Politzer et al. (11) using experimental thermochemical data. The sublimation rate constant for the rate-controlling step 2 can be represented as k(sub) = 2.18 × 10(12) exp (-30.5 kcal/mol/RT) s(-1), which agrees well with available experimental data within the temperature range studied. The high pressure limit decomposition rate constant for the molecular complex H(3)N···HON(O)NNO(2) can be expressed by k(dec) = 3.18 × 10(13) exp (-15.09 kcal/mol/RT) s(-1). In addition, water molecules were found to increase the sublimation enthalpy of ADN, contrary to that found in the ammonium

  14. Mechanism and kinetics for ammonium dinitramide (ADN) sublimation: a first-principles study.

    Science.gov (United States)

    Zhu, R S; Chen, Hui-Lung; Lin, M C

    2012-11-01

    The mechanism for sublimation of NH(4)N(NO(2))(2) (ADN) has been investigated quantum-mechanically with generalized gradient approximation plane-wave density functional theory calculations; the solid surface is represented by a slab model and the periodic boundary conditions are applied. The calculated lattice constants for the bulk ADN, which were found to consist of NH(4)(+)[ON(O)NNO(2)](-) units, instead of NH(4)(+)[N(NO(2))(2)](-), agree quite well with experimental values. Results show that three steps are involved in the sublimation/decomposition of ADN. The first step is the relaxation of the surface layer with 1.6 kcal/mol energy per NH(4)ON(O)NNO(2) unit; the second step is the sublimation of the surface layer to form a molecular [NH(3)]-[HON(O)NNO(2)] complex with a 29.4 kcal/mol sublimation energy, consistent with the experimental observation of Korobeinichev et al. (10) The last step is the dissociation of the [H(3)N]-[HON(O)NNO(2)] complex to give NH(3) and HON(O)NNO(2) with the dissociation energy of 13.9 kcal/mol. Direct formation of NO(2) (g) from solid ADN costs a much higher energy, 58.3 kcal/mol. Our calculated total sublimation enthalpy for ADN(s) → NH(3)(g) + HON(O)NNO(2)) (g), 44.9 kcal/mol via three steps, is in good agreement with the value, 42.1 kcal/mol predicted for the one-step sublimation process in this work and the value 44.0 kcal/mol computed by Politzer et al. (11) using experimental thermochemical data. The sublimation rate constant for the rate-controlling step 2 can be represented as k(sub) = 2.18 × 10(12) exp (-30.5 kcal/mol/RT) s(-1), which agrees well with available experimental data within the temperature range studied. The high pressure limit decomposition rate constant for the molecular complex H(3)N···HON(O)NNO(2) can be expressed by k(dec) = 3.18 × 10(13) exp (-15.09 kcal/mol/RT) s(-1). In addition, water molecules were found to increase the sublimation enthalpy of ADN, contrary to that found in the ammonium

  15. Methods to Stabilize and Destabilize Ammonium Borohydride

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Thomas K.; Karkamkar, Abhijeet J.; Bowden, Mark E.; Besenbacher, Fleming; Jensen, Torben R.; Autrey, Thomas

    2013-01-21

    Ammonium borohydride, NH4BH4, has a high hydrogen content of ρm = 24.5 wt% H2 and releases 18 wt% H2 below T = 160 °C. However, the half-life of bulk NH4BH4 at ambient temperatures, ~6 h, is insufficient for practical applications. The decomposition of NH4BH4 (ABH2) was studied at variable hydrogen and argon back pressures to investigate possible pressure mediated stabilization effects. The hydrogen release rate from solid ABH2 at ambient temperatures is reduced by ~16 % upon increasing the hydrogen back pressure from 5 to 54 bar. Similar results were obtained using argon pressure and the observed stabilization may be explained by a positive volume of activation in the transition state leading to hydrogen release. Nanoconfinement in mesoporous silica, MCM-41, was investigated as alternative means to stabilize NH4BH4. However, other factors appear to significantly destabilize NH4BH4 and it rapidly decomposes at ambient temperatures into [(NH3)2BH2][BH4] (DADB) in accordance with the bulk reaction scheme. The hydrogen desorption kinetics from nanoconfined [(NH3)2BH2][BH4] is moderately enhanced as evidenced by a reduction in the DSC decomposition peak temperature of ΔT = -13 °C as compared to the bulk material. Finally, we note a surprising result, storage of DADB at temperature < -30 °C transformed, reversibly, the [(NH3)2BH2][BH4] into a new low temperature polymorph as revealed by both XRD and solid state MAS 11B MAS NMR. TA & AK are thankful for support from the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. A portion of the research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated by Battelle.

  16. 76 FR 49449 - Continuation of Antidumping Duty Order on Solid Fertilizer Grade Ammonium Nitrate From the...

    Science.gov (United States)

    2011-08-10

    ... International Trade Administration Continuation of Antidumping Duty Order on Solid Fertilizer Grade Ammonium... duty investigation on solid fertilizer grade ammonium nitrate (``ammonium nitrate'') from the Russian... Initiation of Five-Year (``Sunset'') Review, 76 FR 11202 (March 1, 2011) and Ammonium Nitrate from...

  17. Thermal Diffusivity and Specific Heat Measurements of Titanium Potassium Perchlorate Titanium Subhydride Potassium Perchlorate 9013 Glass 7052 Glass SB-14 Glass and C-4000 Muscovite Mica Using the Flash Technique.

    Energy Technology Data Exchange (ETDEWEB)

    Specht, Paul Elliott; Cooper, Marcia A.

    2015-02-01

    The flash technique was used to measure the thermal diffusivity and specific heat of titanium potassium perchlorate (TKP) ignition powder (33wt% Ti - 67wt% KP) with Ventron sup- plied titanium particles, TKP ignition powder (33wt% Ti - 67wt% KP) with ATK supplied titanium particles, TKP output powder (41wt% Ti - 59wt% KP), and titanium subhydride potassium perchlorate (THKP) (33wt% TiH 1.65 - 67wt% KP) at 25 o C. The influence of density and temperature on the thermal diffusivity and specific heat of TKP with Ventron supplied titanium particles was also investigated. Lastly, the thermal diffusivity and specific heats of 9013 glass, 7052 glass, SB-14 glass, and C-4000 Muscovite mica are presented as a function of temperature up to 300 o C.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-12-15

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

  19. Effects of Temperature and Drying and Wetting Alternation on Ammonium Fixation in Manured Loessial Soil

    Institute of Scientific and Technical Information of China (English)

    FANXIAOLIN; LILING; 等

    1996-01-01

    Effects of temperature and drying and wetting alternation (DWA) on ammonium fixation in manured loessial soil were studied by means of Batch Equilibrium with varying concentration solutions of ammonium chloride.ammonium fixation time,and soil clay contents.The purpose of the research was to find out the pattern of ammonium fixation affected by the varying factors.The results showed a remarkable variation in ammonium fixation.Fixed ammonium increased with temperature and treatments of DWA.The ammonium fixation in manured loessial soil was characterized by the effect of temperature and DWA.

  20. Perchlorate and selected metals in water and soil within Mount Rushmore National Memorial, South Dakota, 2011–15

    Science.gov (United States)

    Hoogestraat, Galen K.; Rowe, Barbara L.

    2016-04-14

    Mount Rushmore National Memorial is located in the east-central part of the Black Hills area of South Dakota and is challenged to provide drinking water to about 3 million annual visitors and year-round park personnel. An environmental concern to water resources within Mount Rushmore National Memorial has been the annual aerial fireworks display at the memorial for the Independence Day holiday during 1998–2009. A major concern of park management is the contamination of groundwater and surface water by perchlorate, which is used as an oxidizing agent in firework displays. A study by the U.S. Geological Survey, in cooperation with the National Park Service, was completed to characterize the occurrence of perchlorate and selected metals (constituents commonly associated with fireworks) in groundwater and surface water within and adjacent to Mount Rushmore National Memorial during 2011–15. Concentrations of perchlorate and metals in 106 water samples (collected from 6 groundwater sites and 14 surface-water sites) and 11 soil samples (collected from 11 soil sites) are reported.Within the Mount Rushmore National Memorial boundary, perchlorate concentrations were greatest in the Lafferty Gulch drainage basin, ranging from less than 0.20 to 38 micrograms per liter (μg/L) in groundwater samples and from 2.2 to 54 μg/L in surface-water samples. Sites within the Starling Gulch drainage basin also had some evidence of perchlorate contamination, with concentrations ranging from 0.61 to 19 μg/L. All groundwater and surface-water samples within the unnamed tributary to Grizzly Bear Creek drainage basin and reference sites outside the park boundary had concentrations less than 0.20 μg/L. Perchlorate concentrations in samples collected at the 200-foot-deep production well (Well 1) ranged from 17 to 38 μg/L with a median of 23 μg/L, whereas perchlorate concentrations in samples from the 500-foot-deep production well (Well 2) ranged from 2.1 to 17 μg/L, with a median of 6

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

    Directory of Open Access Journals (Sweden)

    Hai-Bin Zhu

    2010-12-01

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

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

    Directory of Open Access Journals (Sweden)

    James D. Buchner

    2010-09-01

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

  3. Vibrational Spectroscopic Study on Ion Solvation and Association of Lithium Perchlorate in 4-Methoxymethyl-ethylene Carbonate

    Institute of Scientific and Technical Information of China (English)

    QIAO,Hong-Wei; LUAN,He-Lin; ZHOU,Zhi-Ming; YAO,Wen

    2007-01-01

    Solvation interaction and ion association in solutions of lithium perchlorate/4-methoxymethyl-ethylene carbonate(MEC)have been studied by using Infrared and Raman spectra as a function of concentration of lithium perchlorate.The splitting of ring deformation band and ring ether asymmetric stretching band,and the change of Carbonyl stretching band suggest that there should be a strong interaction between Li+ and the solvent molecules,and the site of solvation should be the oxygen atom of carbonyl group.The apparent solvation number of Li+ was calculated by using band fitting technique.The solvation number was decreased from 3.3 to 1.1 with increasing the concentration of LiClO4/MEC solutions.On the other hand,the band fitting for the ClO ̄4 band revealed the presence of contact ion pair,and free ClO ̄4 anion in the concentrated solutions.

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

    Energy Technology Data Exchange (ETDEWEB)

    Blount, Benjamin C. [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341 (United States)]. E-mail: bblount@cdc.gov; Valentin-Blasini, Liza [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341 (United States)

    2006-05-10

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

  5. Concentration of zinc ions in perchlorate medium by a menbrane-gel using an acid extractant (DEHPA)

    OpenAIRE

    Belhadji L.; Belkacemi F.; Hadj-Boussaad D.E.

    2013-01-01

    Recent decades, it is an awareness of the importance of ecological balance in the environment, balances threatened by industrial pollution. A new spirit presides we seek to minimize pollution of receiving waters. The present work is to study the liquid-gel-extraction of zinc ions in perchlorate medium by an acid extractant: the di (ethyl-2 hexyl) phosphorique acid, or DEHPA. Two types of polymers were used as supports of solvent extraction: a polybutadiene rubber cross-linked respectively wit...

  6. Reactions between cerium(IV) and methyl-6-x-derivatives of aniline in perchloric acid solutions

    International Nuclear Information System (INIS)

    The oxidation of 2,6-dimethyl-, 2-isopropyl-6-methyl, 2-chloro-6-methyl-and 2-methyl-6-nitro aniline with cerium(IV) in perchloric acid solutions has been examined. It has been found that the concentration of hydrogen ions and the basicity of nitrogen atom in the amine group decide about the resultant intermediate products. Some of these products can be practically prepared using cerium(IV) as an oxidizing agent. (author). 16 refs, 1 tab

  7. Quaternary ammonium salt derivatives of allylphenols with peripheral analgesic effect

    Directory of Open Access Journals (Sweden)

    A. B de Oliveira

    1991-01-01

    Full Text Available Ammonium salt derivatives of natural allylphenols were synthesized with the purpose of obtaining potential peripheral analgesics. These drugs, by virtue of their physicochemical properties, would not be able to cross the blood brain barrier. Their inability to enter into the central nervous system (CNS should prevent several adverse effects observed with classical opiate analgesics (Ferreira et al., 1984. Eugenol (1 O-methyleugenol (5 and safrole (9 were submitted to nitration, reduction and permethylation, leading to the ammonium salts 4, 8 and 12. Another strategy applied to eugenol (1, consisting in its conversion to a glycidic ether (13, opening the epoxide ring with secondary amines and methylation, led to the ammonium salts 16 and 17. All these ammonium salts showed significant peripheral analgesic action, in modified version of the Randall-Sellito test (Ferreira et al. 1978, at non-lethal doses. The ammonium salt 8 showed an activity comparable to that of methylnalorphinium, the prototype of an ideal peripheral analgesic (Ferreira et al., 1984.

  8. Difficultly Extractable Fixed Ammonium in Some Soils of China

    Institute of Scientific and Technical Information of China (English)

    CHENBIYUN; CHENGLILI; 等

    1999-01-01

    Ninety-three soil samples and 19 sedimentary rock samples collected from 21 provinces of China were analyzed for their contents of fixed ammonium and total N by Kjeldahl-HF method.Results showed that amount of difficultly extractable fixed ammonium(the fixed ammonium that is not determinable by Kjeldahl procedures commonly used for soils) in soils ranged from 0 to 202 mg kg-1,It was generally more than 50 mg kg-1 in soils in Changji and Turpan districts,Xinjiang,accounting for 3.2%-36.8% with an average of 13.9% of the total N.For some Orthents derived from purple shale and purple sandstone in Sichuan and Hunan provinces and Chao soils derived from secondary loess in Henan Province and Ningxia Autonomous Region it was generally around 30 mg kg-1,accounting for 4%-7% of the total soil N,and for most of the rest of soils studied,with the exception of some subsoils,no or trace difficultly extractable fixed ammonium could be detected.It was sugested that the difficultly extractable fixed ammonium was originated from parent rock,and for slightly weathered soils derived from parent materials rich in this form of N the Kjeldahl method might give underestimation of total soil N.

  9. Detection of trace organics in Mars analog samples containing perchlorate by laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Li, Xiang; Danell, Ryan M; Brinckerhoff, William B; Pinnick, Veronica T; van Amerom, Friso; Arevalo, Ricardo D; Getty, Stephanie A; Mahaffy, Paul R; Steininger, Harald; Goesmann, Fred

    2015-02-01

    Evidence from recent Mars missions indicates the presence of perchlorate salts up to 1 wt % level in the near-surface materials. Mixed perchlorates and other oxychlorine species may complicate the detection of organic molecules in bulk martian samples when using pyrolysis techniques. To address this analytical challenge, we report here results of laboratory measurements with laser desorption mass spectrometry, including analyses performed on both commercial and Mars Organic Molecule Analyzer (MOMA) breadboard instruments. We demonstrate that the detection of nonvolatile organics in selected spiked mineral-matrix materials by laser desorption/ionization (LDI) mass spectrometry is not inhibited by the presence of up to 1 wt % perchlorate salt. The organics in the sample are not significantly degraded or combusted in the LDI process, and the parent molecular ion is retained in the mass spectrum. The LDI technique provides distinct potential benefits for the detection of organics in situ on the martian surface and has the potential to aid in the search for signs of life on Mars.

  10. Performance of sulfate-dependent anaerobic ammonium oxidation

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The performance of sulfate-dependent anaerobic ammonium oxidation was studied.The results showed that both SO42-and NH4+ were chemically stable under anaerobic conditions.They did not react with each other in the absence of biological catalyst(sludge).The anaerobic digested sludge cultivated in an anaerobic reactor for three years took on the ability of oxidizing ammonium with sulfate anaero-bically.The average reduction of sulfate and ammonium was 71.67 mg.L-1 and 56.82 mg.L-1 at high concentrations.The reaction between SO42-and NH4+ was difficult,though feasible,due to its low standard Gibbs free energy change.The experiment demonstrated that high substrate concentrations and low oxidation-reduction potential(ORP) may be favourable for the biological reaction.

  11. Performance of sulfate-dependent anaerobic ammo-nium oxidation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lei; ZHENG Ping; HE YuHui; JIN RenCun

    2009-01-01

    The performance of sulfate-dependent anaerobic ammonium oxidation was studied. The results showed that both SO42- and NH4+ were chemically stable under anaerobic conditions. They did not react with each other in the absence of biological catalyst (sludge). The anaerobic digested sludge cultivated in an anaerobic reactor for three years took on the ability of oxidizing ammonium with sulfate anaero-bically. The average reduction of sulfate and ammonium was 71.67 mg.L-1 and 56.82 mg.L-1 at high concentrations.The reaction between SO42- and NH4+ was difficult, though feasible, due to its low standard Gibbs free energy change. The experiment demonstrated that high substrate concentrations and low oxidation-reduction potential (ORP) may be favourable for the biological reaction.

  12. Ammonium transformation in a nitrogen-rich tidal freshwater marsh

    DEFF Research Database (Denmark)

    Gribsholt, B.; Andersson, M.; Boschker, H.T.S.;

    2006-01-01

    The fate and transport of watershed-derived ammonium in a tidal freshwater marsh fringing the nutrient rich Scheldt River, Belgium, was quantified in a whole ecosystem 15N labeling experiment. In late summer (September) we added 15N-NH4+ to the flood water entering a 3477 m2 tidal freshwater marsh...... area, and traced the ammonium processing and retention in four subsequent tide cycles. In this paper we present the results for the water-phase components of the marsh system and compare them to a similar experiment conducted in spring/early summer (May). Changes in concentration and isotopic......, but the absolute ammonium transformation rate was 3 times higher in May. While the marsh surface area was crucial for nitrification in May this was less pronounced in September. Denitrification, on the other hand, appeared more important in September compared to May....

  13. The biological activity of quaternary ammonium salts (QASs

    Directory of Open Access Journals (Sweden)

    Ewa Obłąk

    2010-04-01

    Full Text Available Quaternary ammonium salts (QASs, especially those of cationic surfactant character, are applied as antibacterial and antifungal disinfectants. QASs affect lipid-enveloped viruses, including human immunodeficiency virus (HIV and hepatitis B virus (HBV, but not non-enveloped viruses. These compounds are extensively used in domestic (as ingredients of shampoos, hair conditioners, agricultural (as fungicides, pesticides, insecticides, healthcare (as medications, and industrial applications (as biocides, fabric softeners, corrosion inhibitors. The extensive use of quaternary ammonium disinfectants in recent years has led to the development of resistance in microorganisms to these drugs. Thus [i]Staphylococcus[/i] [i]aureus[/i] strains contain the plasmid-carrying genes [i]qacA[/i] and [i]qacB [/i]encoding resistance to quaternary ammonium compounds and acriflavine. The membrane proteins QacA and QacB confer multidrug resistance by exporting the compound by the proton motive force which is generated by the transmembrane electrochemical proton gradient.

  14. Handling of Ammonium Nitrate Mother-Liquid Radiochemical Production - 13089

    International Nuclear Information System (INIS)

    The aim of the work is to develop a basic technology of decomposition of ammonium nitrate stock solutions produced in radiochemical enterprises engaged in the reprocessing of irradiated nuclear fuel and fabrication of fresh fuel. It was necessary to work out how to conduct a one-step thermal decomposition of ammonium nitrate, select and test the catalysts for this process and to prepare proposals for recycling condensation. Necessary accessories were added to a laboratory equipment installation decomposition of ammonium nitrate. It is tested several types of reducing agents and two types of catalyst to neutralize the nitrogen oxides. It is conducted testing of modes of the process to produce condensation, suitable for use in the conversion of a new technological scheme of production. It is studied the structure of the catalysts before and after their use in a laboratory setting. It is tested the selected catalyst in the optimal range for 48 hours of continuous operation. (authors)

  15. Enrichment culture of marine anaerobic ammonium oxidation (anammox) bacteria

    Institute of Scientific and Technical Information of China (English)

    GUAN Yong-jie

    2016-01-01

    The present study investigates the enrichment of anaerobic ammonium oxidation (anammox) bacteria in the marine environment using sediment samples obtained from the East China Sea and discusses the nitrogen removal efficiency of marine anammox bioreactor. Enrichment of anammox bacteria with simultaneous removal of nitrite and ammonium ions was observed in the Anaerobic Sequencing Batch Reactor under a total nitrogen loading rate of 0.37kg-N m-3day-1. In this study, The nitrogen removal efficiency was up to 80% and the molar-reaction ratio of ammonium, nitrite and nitrate was 1.0:1.22:0.22 which was a little different from a previously reported ratio of 1.0:1.32:0.26 in a freshwater system.

  16. Thermodynamics of the complexation of ciprofloxacin with calcium and magnesium perchlorate

    International Nuclear Information System (INIS)

    Highlights: → The thermodynamics of the reactions of ciprofloxacin (CIP) with Ca(ClO4)2 and Mg(ClO4)2 were investigated by conductometric titration. → The reactions of CIP with each ion produce two ionic complexes with the formulas M(CIP)2+ and M(CIP)22+. → The change in enthalpy and entropy were negative which indicate that the complexation is driven by the enthalpy change. - Abstract: The thermodynamics of the reactions of ciprofloxacin (CIP) with calcium perchlorate (Ca(ClO4)2) and magnesium perchlorate (Mg(ClO4)2) have been investigated in water-methanol solvent using conductometric titration. The reactions of CIP with each ion produce two ionic complexes with the general formulas M(CIP)2+ and M(CIP)22+. The stability constants K1 and K2 at 25 oC for the complexes formed from the reaction with Ca(ClO4)2 were 8.84 x 104 and 3.62 x 104, respectively. For the reaction with Mg(ClO4)2K1 and K2 were 1.72 x 105 and 2.50 x 103, respectively. The enthalpy (ΔH1, ΔH2, ΔH12) and entropy (ΔS1, ΔS2, ΔS12) of complexation reactions were determined from the temperature dependence of the complexation constants. The reactions of CIP with both ions are accompanied by a decrease in entropy (ΔS12 = -468.12 and -478.89 J/K mol for complexation with Ca(ClO4)2 and Mg(ClO4)2, respectively) and enthalpy (ΔH12 = -193.09 and -192.01 kJ/mol for complexation with Ca(ClO4)2 and Mg(ClO4)2, respectively), which indicate that the reactions are driven by the enthalpy change.

  17. Thermodynamics of the complexation of ciprofloxacin with calcium and magnesium perchlorate

    Energy Technology Data Exchange (ETDEWEB)

    Al-Mustafa, Jamil, E-mail: malkawi@just.edu.jo [Department of Applied Chemistry, Faculty of Arts and Sciences, Jordan University of Science and Technology, P.O. Box 3030, Irbid (Jordan); Taha, Ziyad A. [Department of Applied Chemistry, Faculty of Arts and Sciences, Jordan University of Science and Technology, P.O. Box 3030, Irbid (Jordan)

    2011-07-10

    Highlights: {yields} The thermodynamics of the reactions of ciprofloxacin (CIP) with Ca(ClO{sub 4}){sub 2} and Mg(ClO{sub 4}){sub 2} were investigated by conductometric titration. {yields} The reactions of CIP with each ion produce two ionic complexes with the formulas M(CIP){sup 2+} and M(CIP){sub 2}{sup 2+}. {yields} The change in enthalpy and entropy were negative which indicate that the complexation is driven by the enthalpy change. - Abstract: The thermodynamics of the reactions of ciprofloxacin (CIP) with calcium perchlorate (Ca(ClO{sub 4}){sub 2}) and magnesium perchlorate (Mg(ClO{sub 4}){sub 2}) have been investigated in water-methanol solvent using conductometric titration. The reactions of CIP with each ion produce two ionic complexes with the general formulas M(CIP){sup 2+} and M(CIP){sub 2}{sup 2+}. The stability constants K{sub 1} and K{sub 2} at 25 {sup o}C for the complexes formed from the reaction with Ca(ClO{sub 4}){sub 2} were 8.84 x 10{sup 4} and 3.62 x 10{sup 4}, respectively. For the reaction with Mg(ClO{sub 4}){sub 2}K{sub 1} and K{sub 2} were 1.72 x 10{sup 5} and 2.50 x 10{sup 3}, respectively. The enthalpy ({Delta}H{sub 1}, {Delta}H{sub 2}, {Delta}H{sub 12}) and entropy ({Delta}S{sub 1}, {Delta}S{sub 2}, {Delta}S{sub 12}) of complexation reactions were determined from the temperature dependence of the complexation constants. The reactions of CIP with both ions are accompanied by a decrease in entropy ({Delta}S{sub 12} = -468.12 and -478.89 J/K mol for complexation with Ca(ClO{sub 4}){sub 2} and Mg(ClO{sub 4}){sub 2}, respectively) and enthalpy ({Delta}H{sub 12} = -193.09 and -192.01 kJ/mol for complexation with Ca(ClO{sub 4}){sub 2} and Mg(ClO{sub 4}){sub 2}, respectively), which indicate that the reactions are driven by the enthalpy change.

  18. Spectroscopic study of perchlorates and other oxygen chlorides in a Martian environmental chamber

    Science.gov (United States)

    Wu, Zhongchen; Wang, Alian; Ling, Zongcheng

    2016-10-01

    We report a study where the molecular spectral features of nine anhydrous and hydrous oxygen chlorides were analyzed both under Mars atmospheric pressure and temperature conditions in a Planetary Environment and Analysis Chamber (PEACh) and, for comparison, under ambient laboratory conditions. The goal is to understand the effect of Mars environmental conditions (mainly temperature T and CO2 pressure P) on their spectral features as determined by both Raman and NIR spectroscopy. These results will be used for in situ simultaneous identification of the Cl O4- and other intermediate oxygen chloride products generated during a dynamic electrostatic discharge (ESD) experiment. We have three major findings from the first phase of this study: (1) the ν1 Raman peak position is the most sensitive parameter for identifying the cation speciation in perchlorates (e.g., Na, Mg, Ca), the hydration state of magnesium perchlorate (e.g., Mg(ClO4)2 ṡ xH2O, x = 0 , 2 , 4 , 6), and the degree of oxidation of sodium oxygen chlorides (e.g., NaClOy, y = 1 , 2 , 3 , 4); (2) ν1 Raman peak positions of most tested hydrous and anhydrous oxygen chlorides show no detectable changes within the tested T and P ranges relevant to the environmental conditions at Mars surface and shallow subsurface, but water Raman peaks of the hydrated salts change following T decreases; (3) under the P &T conditions relevant to current surface and shallow subsurface at Mars mid-latitude regions, both Mg(ClO4)2 ṡ 6H2O and Ca(ClO4)2 ṡ 2H2O are stable against dehydration, while NaClO4 ṡ H2O dehydrates, with a dehydration rate that is a function of T which was quantified by in situ NIR spectroscopy. These results are useful for the interpretations of the data from current orbital remote sensing (Vis-NIR spectra) and from future landed missions (Raman spectra). Furthermore, we have designed a set of systematic ESD experiments to be conducted in PEACh for studying the pathways and the rates of oxygen chloride

  19. Anomalous aryl strengthening of complexes at americium and europium extraction with alkylenediphospine dioxide from perchloric media

    International Nuclear Information System (INIS)

    Studied was the extraction of americium(3) and europium(3) from perchlorate solutions(0.001 M) with dioxides of alkylenediphosphines of three types: aryl Ph2P(O)CH2(O)PPh2(briefly 4P), and Ph2P(O)(CH2)2(O)PPh2, mixed Ph2P(O)CH2(O)P(C8H17)2 (or 2Ph2Oct) and alkyl (C8H17)2P(O)CH2(O)P(C8H17)2 (or 4 Oct). Trisolvates of MeS3x(ClO4)3 are predominantly formed but americium disolvates are also present upon dilution with dichloroethane. For 4Ph,2Ph2Oct and 4 Oct the concentration is, respectively, 1015, 2x1014, and 1013; for disolvates by 4 orders of magnitude lower which is, nevertheless, by 2 orders of magnitude higher than for nitric acid solutions. The separation coefficient of β Am/Eu for 4Ph attains 6-8. As in the case of nitrate solutions, an anomalous aryl strengthening of the complexes is observed: an increase in the distribution coefficients and extraction constants in the series of 4 Oct - 2Ph 2 Oct - 4Ph, in spite of the introduction of electronegative aryl substituents into the dioxide molecule, which reduce electron density on oxygen atoms and basicity of dioxides. In contrast to nitric acid solutions, observed is a nonlinear effect of a change in basicity on extraction properties upon dilution with dichloroethane (dioxide of 2Ph2 Oct does not occupy an intermediate position but is close to 4Ph). Upon dilution with chloroform the dependence is linear and anomalous effect rises due to a different nature of interactions of dioxides with chloroform. When the bridge increases up to ethylene, an anomalous strengthening of the complexes disappears. However, the distribution coefficients upon extraction with alkyl dioxide are considerably lower, which can be explained by a stronger extraction of perchloric acid

  20. Removal of toxic ions (chromate, arsenate, and perchlorate) using reverse osmosis, nanofiltration, and ultrafiltration membranes

    KAUST Repository

    Yoon, Jaekyung

    2009-09-01

    Rejection characteristics of chromate, arsenate, and perchlorate were examined for one reverse osmosis (RO, LFC-1), two nanofiltration (NF, ESNA, and MX07), and one ultrafiltration (UF and GM) membranes that are commercially available. A bench-scale cross-flow flat-sheet filtration system was employed to determine the toxic ion rejection and the membrane flux. Both model and natural waters were used to prepare chromate, arsenate, and perchlorate solutions (approximately 100 μg L-1 for each anion) in mixtures in the presence of other salts (KCl, K2SO4, and CaCl2); and at varying pH conditions (4, 6, 8, and 10) and solution conductivities (30, 60, and 115 mS m-1). The rejection of target ions by the membranes increases with increasing solution pH due to the increasingly negative membrane charge with synthetic model waters. Cr(VI), As(V), and ClO4 - rejection follows the order LFC-1 (>90%) > MX07 (25-95%) ≅ ESNA (30-90%) > GM (3-47%) at all pH conditions. In contrast, the rejection of target ions by the membranes decreases with increasing solution conductivity due to the decreasingly negative membrane charge. Cr(VI), As(V), and ClO4 - rejection follows the order CaCl2 < KCl ≅ K2SO4 at constant pH and conductivity conditions for the NF and UF membranes tested. For natural waters the LFC-1 RO membrane with a small pore size (0.34 nm) had a significantly greater rejection for those target anions (>90%) excluding NO3 - (71-74%) than the ESNA NF membrane (11-56%) with a relatively large pore size (0.44 nm), indicating that size exclusion is at least partially responsible for the rejection. The ratio of solute radius (ri,s) to effective membrane pore radius (rp) was employed to compare ion rejection. For all of the ions, the rejection is higher than 70% when the ri,s/rp ratio is greater than 0.4 for the LFC-1 membrane, while for di-valent ions (CrO4 2 -, SO4 2 -, and HAsSO4 2 -) the rejection (38-56%) is fairly proportional to the ri,s/rp ratio (0.32-0.62) for the ESNA

  1. Steady state growth of E. Coli in low ammonium environment

    Science.gov (United States)

    Kim, Minsu; Deris, Barret; Zhang, Zhongge; Hwa, Terry

    2011-03-01

    Ammonium is the preferred nitrogen source for many microorganisms. In medium with low ammonium concentrations, enteric bacteria turn on the nitrogen responsive (ntr) genes to assimilate ammonium. Two proteins in E. coli, Glutamine synthetase (GS) and the Ammonium/methylammonium transporter AmtB play crucial roles in this regard. GS is the major ammonium assimilation enzyme below 1mM of NH4 + . AmtB is an inner membrane protein that transports NH4 + across the cell membrane against a concentration gradient. In order to study ammonium uptake at low NH4 + concentration at neutral pH, we developed a microfluidic flow chamber that maintains a homogenous nutrient environment during the course of exponential cell growth, even at very low concentration of nutrients. Cell growth can be accurately monitored using time-lapse microscopy. We followed steady state growth down to micro-molar range of NH4 + for the wild type and Δ amtB strains. The wild type strain is able to maintain the growth rate from 10mM down to a few uM of NH4 + , while the mutant exhibited reduced growth below ~ 20 ~uM of NH4 + . Simultaneous characterization of the expression levels of GS and AmtB using fluorescence reporters reveals that AmtB is turned on already at 1mM, but contributes to function only below ~ 30 ~uM in the wild-type. Down to ~ 20 ~uM of NH4 + , E.~coli can compensate the loss of AmtB by GS alone.

  2. Laboratory studies of ice formation pathways from ammonium sulfate particles

    Directory of Open Access Journals (Sweden)

    M. E. Wise

    2008-08-01

    Full Text Available Cirrus clouds are composed of ice particles and their formation pathways have been studied extensively in the laboratory. The ability of ammonium sulfate particles to act as nuclei for cirrus clouds has been of particular importance because of their ubiquitous presence in the upper troposphere. The results of past laboratory experiments of homogeneous ice nucleation from ammonium sulfate particles show a wide range of freezing conditions. In the present study, a flow tube apparatus equipped with Fourier transform infrared spectroscopy was used to resolve these discrepancies. It was found that when ammonium sulfate particles were preconditioned at 100% relative humidity (RH prior to experimentation, the particles froze at conditions predicted by the homogeneous ice nucleation model developed by Koop et al. (2000. If the particles were not preconditioned at 100% RH, they froze at warmer temperatures and lower ice saturation ratios than predicted by Koop et al. (2000. In order to determine if a population of effloresced particles affected freezing conditions for particles that were not preconditioned at 100% RH, a series of depositional ice nucleation experiments were carried out on dry ammonium sulfate particles. For freezing temperatures between 215 and 231 K, ice nucleated on the particles at ice saturation ratios (Sice between 1 and 1.05. These conditions are much lower than predicted by Koop et al. (2000 and explain the differences in freezing conditions among preconditioning methods. In similar experiments, Abbatt et al. (2006 hypothesized that a small fraction of effloresced ammonium sulfate particles induced ice nucleation at Sice values lower than expected. The current study confirms the Abbatt et al. (2006 hypothesis and, to our knowledge, is the first study to directly observe ice nucleating onto freely flowing dry ammonium sulfate particles at Sice values approaching unity.

  3. Immunological detection of small organic molecules in the presence of perchlorates: relevance to the life marker chip and life detection on Mars.

    Science.gov (United States)

    Rix, Catherine S; Sims, Mark R; Cullen, David C

    2011-11-01

    The proposed ExoMars mission, due to launch in 2018, aims to look for evidence of extant and extinct life in martian rocks and regolith. Previous attempts to detect organic molecules of biological or abiotic origin on Mars have been unsuccessful, which may be attributable to destruction of these molecules by perchlorate salts during pyrolysis sample extraction techniques. Organic molecules can also be extracted and measured with solvent-based systems. The ExoMars payload includes the Life Marker Chip (LMC) instrument, capable of detecting biomarker molecules of extant and extinct Earth-like life in liquid extracts of martian samples with an antibody microarray assay. The aim of the work reported here was to investigate whether the presence of perchlorate salts, at levels similar to those at the NASA Phoenix landing site, would compromise the LMC extraction and detection method. To test this, we implemented an LMC-representative sample extraction process with an LMC-representative antibody assay and used these to extract and analyze a model sample that consisted of a Mars analog sample matrix (JSC Mars-1) spiked with a representative organic molecular target (pyrene, an example of abiotic meteoritic infall targets) in the presence of perchlorate salts. We found no significant change in immunoassay function when using pyrene standards with added perchlorate salts. When model samples spiked with perchlorate salts were subjected to an LMC-representative liquid extraction, immunoassays functioned in a liquid extract and detected extracted pyrene. For the same model sample matrix without perchlorate salts, we observed anomalous assay signals that coincided with yellow coloration of the extracts. This unexpected observation is being studied further. This initial study indicates that the presence of perchlorate salts, at levels similar to those detected at the NASA Phoenix landing site, is unlikely to prevent the LMC from extracting and detecting organic molecules from

  4. Mutagenic activity of quaternary ammonium salt derivatives of carbohydrates

    Science.gov (United States)

    Sikora, Karol; Woziwodzka, Anna; Piosik, Jacek; Podgórska, Beata

    2016-01-01

    Summary This paper presents a study on a series of quaternary ammonium salt (QAS) derivatives of glucopyranosides with an elongated hydrophobic hydrocarbon chain. The new N-[6-(β-D-glucopyranosyloxy)hexyl]ammonium bromides and their O-acetyl derivatives were analyzed via 1H and 13C NMR spectroscopy. The mutagenic activity of the newly synthesized QAS was investigated using two different techniques: The Vibrio harveyi luminescence assay and the Ames test. The obtained results support previous findings contesting QAS safety and indicate that QAS, specifically pyridinium derivatives, might be mutagenic. PMID:27559394

  5. Effect of peroxodisulfate on uranium leaching with ammonium bicarbonate

    Directory of Open Access Journals (Sweden)

    Nurbek Nurpeisov

    2013-05-01

    Full Text Available In this study, uranium leaching from ore material using acid solution and bicarbonate in a presence peroxodisulfate ion was examined. For experiments two different tips of leaching methods were used: leaching in static and dynamic conditions. The determination of uranium concentrations in product solutions were analyzed by titrimetric (by ammonia vanadate solution method. The maximum yield of uranium leached with ammonium bicarbonate in a presence of ammonium peroxodisulfate (5 g/L was only 33%, which is half the corresponding value obtained by sulfuric acid (65%.

  6. Tripropyl­ammonium trithio­cyanurate

    OpenAIRE

    Yang, Yunxia

    2010-01-01

    In the title compound (systematic name: tripropyl­azanium 2,4,6-tris­ulfanyl­idene­cyclo­hexan-1-ide), (C3H7)3HN+·C3H2N3S3 −, one H atom of trithio­cyanuric acid is accepted by tripropyl­amine to form the ammonium ion. Coplanar trithio­cyanurate and tripropyl­ammonium ions [dihedral angle = 82.33 (8)°] form the salt, which is stabilised by various N—H⋯S and N—H⋯N contacts.

  7. Tripropyl­ammonium trithio­cyanurate

    Science.gov (United States)

    Yang, Yunxia

    2010-01-01

    In the title compound (systematic name: tripropyl­azanium 2,4,6-tris­ulfanyl­idene­cyclo­hexan-1-ide), (C3H7)3HN+·C3H2N3S3 −, one H atom of trithio­cyanuric acid is accepted by tripropyl­amine to form the ammonium ion. Coplanar trithio­cyanurate and tripropyl­ammonium ions [dihedral angle = 82.33 (8)°] form the salt, which is stabilised by various N—H⋯S and N—H⋯N contacts. PMID:21588990

  8. Aerosol isotopic ammonium signatures over the remote Atlantic Ocean

    Science.gov (United States)

    Lin, C. T.; Jickells, T. D.; Baker, A. R.; Marca, A.; Johnson, M. T.

    2016-05-01

    We report aerosol ammonium 15N signatures for samples collected from research cruises on the South Atlantic and Caribbean using a new high sensitivity method. We confirm a pattern of isotopic signals from generally light (δ15N -5 to -10‰), for aerosols with very low (ocean, to generally heavier values (δ15N +5 to +10‰), for aerosols collected in temperate and tropical latitudes and with higher ammonium concentrations (>2  nmol m-3). We discuss whether this reflects a mixing of aerosols from two end-members (polluted continental and remote marine emissions), or isotopic fractionation during aerosol transport.

  9. Determination of Ammonium Ion in Lake Water by Voltammetry

    Institute of Scientific and Technical Information of China (English)

    Wu Yun-hua; Fei Jun-jie; Dang Xue-ping; Hu Sheng-shui

    2004-01-01

    An electroanalytical method for the determination of armonium ion using a platinized platinum electrode is described. Under optimized analytical conditions, the linear range of the calibration graphs for ammonium ion is 3. 0×10(-5)-5.0×10-3 mol·L-1.The Method has been applide to the determination of ammonium ion in lake water samples and recoveries of 100%-103%0 are obtained. The results obtained are found to be in good agreement with spectrophotometric results.

  10. Ferroelectric Polarization Switching Dynamics and Domain Growth of Triglycine Sulfate and Imidazolium Perchlorate

    KAUST Repository

    Ma, He

    2016-04-10

    The weak bond energy and large anisotropic domain wall energy induce many special characteristics of the domain nucleation, growth, and polarization switch in triglycine sulfate (TGS) and imidazolium perchlorate (IM), two typical molecular ferroelectrics. Their domain nucleation and polarization switch are rather slower than those of conventional oxide ferroelectrics, which may be due to the weaker bond energy of hydrogen bond or van der Waals bond than that of ionic bond. These chemical bonds dominate the elastic energy, with the latter being an important component of domain wall energy and playing an important role in domain nucleation and domain growth. The ratio of anisotropic domain wall energy to Gibbs free energy is large in TGS and IM, which allows a favorable domain shape and a special domain evolution under a certain electric field. Therefore, this study not only sheds light on the physical nature but also indicates the application direction for molecular ferroelectrics. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  11. (2,2′-Bipyridine(2-formyl-6-methoxyphenolatonickel(II perchlorate

    Directory of Open Access Journals (Sweden)

    Cui-Juan Wang

    2009-01-01

    Full Text Available In the title compound, [Ni(C8H7O3(C10H8N2]ClO4, the NiII atom is in a slightly distorted square-planar coordination by two N atoms from the 2,2′-bipyridine (bipy ligand and two O atoms from the deprotonated 2-formyl-6-methoxyphenolate (mbd ligand. The bipy ligand is nearly coplanar with the NiII square plane, the Ni atom being only 0.042 (2 Å from the mean plane, whereas the benzaldehyde plane is folded with respect to the square plane, making a dihedral angle of 19.17 (8°. One of the O atoms of the perchlorate anion is involved in a weak interaction with the Ni atom, with an Ni—O distance of 2.5732 (18 Å. The packing is stabilized by weak C—H...O interactions.

  12. Determination of ammonium sulphate in ammonia alum by formaldehyde reaction

    Directory of Open Access Journals (Sweden)

    Amir Chand

    1962-01-01

    Full Text Available Existing methods for the estimation of ammonium salts in presence of hydrolysable salts have been reviewed. A new titrimetric method utilizing formaldehyde and potassium fluoride is described for its estimation in presence of aluminium sulphate. The method is accurate and rapid for routine analysis.

  13. Aqueous Media Oxidation of Alcohols with Ammonium Persulfate

    Institute of Scientific and Technical Information of China (English)

    IMANZADEH, Gholam Hassan; ZAMANLOO, Mohammad R.; MANSOORI, Yaghoob; KHODAYARI, Ali

    2007-01-01

    Oxidation of series of various primary and secondary alcohols to corresponding carbonyl compounds with ammonium persulfate in aqueous media was described. No over oxidation of primary alcohols to carboxylic acids and secondary alcohols to esters was observed. Under such conditions benzoin was converted to benzoic acid.

  14. Treating leachate mixture with anaerobic ammonium oxidation technology

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-guo; ZHOU Shao-qi

    2006-01-01

    Large amounts of ammonium and a low content of biodegradable chemical oxygen demand(COD) are contained in leachate from aged landfills, together with the effluent containing high concentration of nitric nitrogen after biochemical treatment.Treatment effect of anaerobic ammonium oxidation (anammox) process on the mixture of the leachate and its biochemical effluent was investigated. The results show that the average removal efficiencies of ammonium, nitric nitrogen and total nitrogen are 87.51%,74.95% and 79.59%, respectively, corresponding to the average ratio of removed nitric nitrogen to ammonium, i.e. 1.14 during the steady phase of anammox activity. The mean removal efficiency of COD is only 24.01% during the experimental period. The demand of total phosphorous for the anammox process is unobvious. Especially, the alkalinity and pH value of the effluent are close to those of the influent during the steady phase of anammox activity. In addition, it is demonstrated that the status of the anammox bioreactor can be indicated by the alkalinity and pH value during the course of the experiment. The anammox bioreactor has shown potential for nitrogen removal in the leachate mixture. However, COD and total phosphorous in the leachate mixture need further treatment for removal efficiencies of COD and total phosphorous are not good in the anammox bioreactor.

  15. Characterization of ammonium polyuranate powders from a continuous precipitator

    Energy Technology Data Exchange (ETDEWEB)

    Oolman, T.

    1979-01-01

    Ammonium polyuranate powders produced in a continuous, well-mixed precipitator were characterized by means of electron microscopy. The powders were qualitatively analyzed with the scanning electron microscope and the elementary crystallites were quantivatively analyzed with the transmission electron microscope. The results were fit to a kinetic theory of continuous precipitation. A phase analysis was also preformed by x-ray powder diffraction.

  16. Carboxylates and the uptake of ammonium by excised maize roots

    NARCIS (Netherlands)

    Breteler, H.

    1975-01-01

    The effect of carboxylates (organic acid anions) on NH 4 uptake was studied by changing the carboxylate level of roots prior to uptake experi ments. Succinate was the most effective stimulator of ammonium uptake. The oxocarboxylates (α-oxoglutarate, oxaloacetate and

  17. Fate of N from Green Manures and Ammonium Sulfate

    Institute of Scientific and Technical Information of China (English)

    SHISHU-LIAN; WENQI-XIAO; 等

    1991-01-01

    By means of 15N tracer technique the fate of N in ammonium sulfate,milk vetch,sesbania and azolla,and the availability of their residual N were studied in a microplot experiment.Results showed that a) at the end of the first crop of early rice,both plant recovery and loss of N from ammonium sulfate were the highest whereas those from azolla were the lowest with those from milk vetch and sesbania in between;the sequence was reversed in terms of recovery of N in soil;the net residual N from ammonium sulfate was very low,about 1/7-1/4 of that from green manures,indicating that chemical N fertilizer contributes little to the soil N reserve;b) plant recovery of the residual N was low and it did not always decrease with time;the total plant recovery (from the second to the fifth crops) of the residual N from various test fertilizers was only 8-11% of the total N originally applied;c) the plant recovery of the residual N from ammonium sulfate was the highest,followed by those from milk vetch and sesbania,and that from azolla was the lowest,no matter in which cropping season (from the second to the fifth);N availability ratio showed the same trend,indicating that chemical N fertilizer helps renovate soil organic N,maintain and increase availability of soil N.

  18. Synthetic receptors for ammonium ions using dynamic combinatorial chemistry

    NARCIS (Netherlands)

    Hamieh, Saleh

    2015-01-01

    The general topic of this dissertation is the development of synthetic receptors for organic ammonium ions in near physiological conditions using disulfide dynamic combinatorial chemistry (DCC). Chapter 1 explains the importance of this development and the associated difficulties when using the conv

  19. Characterization of ammonium polyuranate powders from a continuous precipitator

    International Nuclear Information System (INIS)

    Ammonium polyuranate powders produced in a continuous, well-mixed precipitator were characterized by means of electron microscopy. The powders were qualitatively analyzed with the scanning electron microscope and the elementary crystallites were quantivatively analyzed with the transmission electron microscope. The results were fit to a kinetic theory of continuous precipitation. A phase analysis was also preformed by x-ray powder diffraction

  20. Growth features of ammonium hydrogen -tartrate single crystals

    Indian Academy of Sciences (India)

    G Sajeevkumar; R Raveendran; B S Remadevi; Alexander Varghese Vaidyan

    2004-08-01

    Ammonium hydrogen -tartrate (-AHT) single crystals were grown in silica gel. The growth features of these crystals with variation of parameters like specific gravity of the gel, gel pH, acid concentrations, concentration of the feed solution and gel age were studied in detail.

  1. New synthetic method and properties of ammonium dinitramide (ADN)

    Energy Technology Data Exchange (ETDEWEB)

    Hatano, H.; Onda, T.; Shi Ino, K.; Kiname, S.I. [Technical Center, Hosoya Kako, Osawa (Japan); Miyazaki, S.; Suzuki, S. [Research et Development Center, Nissan Motor Co, Saitama (Japan)

    1996-12-31

    Ammonium dinitramide (ADN) is one of the energetic materials, its hazard, however, has never been presented yet. In this paper, new synthetic method of ADN and its properties are contained. It has been found out that ADN has little hazard and is a safe energetic compound. (authors) 4 refs.

  2. Ammonium dinitramide (ADN)-Prilling, coating, and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Heintz, Thomas; Pontius, Heike; Aniol, Jasmin; Birke, Christoph; Leisinger, Karlfred; Reinhard, Werner [Fraunhofer-Institut Chemische Technologie ICT, Pfinztal (Germany)

    2009-06-15

    Ammonium dinitramide (ADN) is the promising oxidizer, which is expected to be applied, e.g., in solid rocket propellants. The manufacturing of spherical ADN particles (the so-called ADN-Prills) with useful morphology and reproducible quality is realized by means of the emulsion crystallization process. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  3. Increase of water resistance of ammonium nitrate explosives

    Directory of Open Access Journals (Sweden)

    Zulkhair Mansurov

    2012-03-01

    Full Text Available Developed a method of kapsulating of ammonium nitrate with liquid paraffin increase finding explosives in water for 60 minutes. Placing explosives in the plastic shell, the explosive was, as in standing or running water during the day. When conducting field tests failures were absent.

  4. Profiling the origin of ammonium nitrate: proof-of-principle

    NARCIS (Netherlands)

    Carol-Visser, J.; Farmache, M.A.; Heijden, A.E.D.M. van der

    2011-01-01

    In many Improvised Explosive Devices (IEDs) the main charge consists of ammonium nitrate (AN). For forensic reasons, screening for the origin of AN is of importance. By assessing specifi c characteristics, diff erent AN batches can be profi led, in this way providing extra information which could le

  5. Simultaneous Nitrite-Dependent Anaerobic Methane and Ammonium Oxidation Processes

    NARCIS (Netherlands)

    Luesken, F.A.; Sánchez. J.; Van Alen, T.A.; Sanabria, J.; Op den Camp, H.J.; Jetten, M.S.; Kartal, B.

    2011-01-01

    itrite-dependent anaerobic oxidation of methane (n-damo) and ammonium (anammox) are two recently discovered processes in the nitrogen cycle that are catalyzed by n-damo bacteria, including "Candidatus Methylomirabilis oxyfera," and anammox bacteria, respectively. The feasibility of coculturing anamm

  6. Antibacterial activity of reactive quaternary ammonium compounds in solution and in nonleachable coatings

    NARCIS (Netherlands)

    Gozzelino, G.; Romero Tobar, D.E.; Chaitiemwong, N.; Hazeleger, W.C.; Beumer, R.R.

    2011-01-01

    Antibacterial polymers suitable for coating applications without leaching of the biocidal component have been obtained by UV copolymerization of acrylic resins with acrylic monomers containing quaternary ammonium moieties. Suitable reactive biocides, based on quaternary ammonium monomers (QAMs), end

  7. Perchlorate and volatiles of the brine of Lake Vida (Antarctica): Implication for the in situ analysis of Mars sediments

    Science.gov (United States)

    Kenig, Fabien; Chou, Luoth; McKay, Christopher P.; Jackson, W. Andrew; Doran, Peter T.; Murray, Alison E.; Fritsen, Christian H.

    2016-07-01

    The cold (-13.4°C), cryoencapsulated, anoxic, interstitial brine of the >27 m thick ice of Lake Vida (Victoria Valley, Antarctica) contains 49 µg · L-1 of perchlorate and 11 µg · L-1 of chlorate. Lake Vida brine (LVBr) may provide an analog for potential oxychlorine-rich subsurface brine on Mars. LVBr volatiles were analyzed by solid-phase microextraction (SPME) gas chromatography-mass spectrometry (GC-MS) with two different SPME fibers. With the exception of volatile organic sulfur compounds, most other volatiles observed were artifacts produced in the GC injector when the thermal decomposition products of oxychlorines reacted with reduced carbon derived from LVBr and the SPME fiber phases. Analysis of MilliQ water with perchlorate (40 µg · L-1) showed low level of organic artifacts, reflecting carbon limitation. In order to observe sample-derived organic compounds, both in analog samples and on Mars, the molar abundance of reduced carbon in a sample must exceed those of O2 and Cl2 produced during decomposition of oxychlorines. This suggests that the abundance of compounds observed by the Sample Analysis at Mars (SAM) instruments in Sheepbed samples (CB-3, CB5, and CB6) may be controlled by an increase in the reduced-carbon/oxychlorine ratio of these samples. To increase chances of in situ detection of Martian organics during pyrolysis-GC-MS, we propose that the derivatization agents stored on SAM may be used as an external source of reduced carbon, increasing artificially the reduced-carbon to perchlorate ratio during pyrolysis, allowing the expression of more abundant and perhaps more diverse Martian organic matter.

  8. Perchlorate and Volatiles of the Brine of Lake Vida (Antarctica): Implication for the in Situ Analysis of Mars Sediments

    Science.gov (United States)

    Kenig, Fabien; Chou, Luoth; McKay, Christopher P.; Jackson, W. Andrew; Doran, Peter T.; Murray, Alison E.; Fritsen, Christian H.

    2016-01-01

    The cold (-13.4 C), cryoencapsulated, anoxic, interstitial brine of the 27 m-thick ice of Lake Vida (Victoria Valley, Antarctica) contains 49 microgram L-1 of perchlorate and 11 microgram L-1 of chlorate. Lake Vida brine (LVBr) may provide an analog for potential oxychlorine-rich subsurface brine on Mars. LVBr volatiles were analyzed by solid-phase microextraction (SPME) gas chromatography-mass spectrometry (GC-MS) with two different SPME fibers. With the exception of volatile organic sulfur compounds, most other volatiles observed were artifacts produced in the GC injector when the thermal decomposition products of oxychlorines reacted with reduced carbon derived from LVBr and the SPME fiber phases. Analysis of MilliQ water with perchlorate (40 microgram L-1) showed low level of organic artifacts, reflecting carbon limitation. In order to observe sample-derived organic compounds, both in analog samples and on Mars, the molar abundance of reduced carbon in a sample must exceed those of O2 and Cl2 produced during decomposition of oxychlorines. This suggests that the abundance of compounds observed by the Sample Analysis at Mars (SAM) instruments in Sheepbed samples (CB-3, CB5, and CB6) may be controlled by an increase in the reduced-carbon/oxychlorine ratio of these samples. To increase chances of in situ detection of Martian organics during pyrolysis-GC-MS, we propose that the derivatization agents stored on SAM may be used as an external source of reduced carbon, increasing artificially the reduced-carbon to perchlorate ratio during pyrolysis, allowing the expression of more abundant and perhaps more diverse Martian organic matter.

  9. Effects of the anti-thyroidal compound potassium-perchlorate on the thyroid system of the zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Florian, E-mail: florian.schmidt@zoo.uni-heidelberg.de [Aquatic Ecology and Toxicology Group, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg (Germany); Schnurr, Sarah; Wolf, Raoul; Braunbeck, Thomas [Aquatic Ecology and Toxicology Group, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg (Germany)

    2012-03-15

    The increasing pollution of aquatic habitats with anthropogenic compounds has led to various test strategies to detect hazardous chemicals. However, information on effects of pollutants in the thyroid system in fish, which is essential for growth, development and parts of reproduction, is still scarce. Other vertebrate groups such as amphibians or mammals are well-studied; so the need for further knowledge especially in fish as a favored vertebrate model test organism is evident. Modified early life-stage tests were carried out with zebrafish exposed to the known thyroid inhibitor potassium perchlorate (0, 62.5, 125, 250, 500 and 5000 {mu}g/L) to identify adverse effects on the hypothalamic-pituitary-thyroid axis. Especially higher perchlorate concentrations led to conspicuous alterations in thyroidal tissue architecture and to effects in the pituitary. In the thyroid, severe hyperplasia at concentrations {>=}500 {mu}g/L together with an increase in follicle number could be detected. The most sensitive endpoint was the colloid, which showed alterations at {>=}250 {mu}g/L. The tinctorial properties and the texture of the colloid changed dramatically. Interestingly, effects on epithelial cell height were minor. The pituitary revealed significant proliferations of TSH-producing cells resulting in alterations in the ratio of adeno- to neurohypophysis. The liver as the main site of T4 deiodination showed severe glycogen depletion at concentrations {>=}250 {mu}g/L. In summary, the thyroid system in zebrafish showed effects by perchlorate from concentrations {>=}250 {mu}g/L, thus documenting a high sensitivity of the zebrafish thyroid gland for goitrogens. In the future, such distinct alterations could lead to a better understanding and identification of potential thyroid-disrupting chemicals.

  10. Systematic evaluation of nitrate and perchlorate bioreduction kinetics in groundwater using a hydrogen-based membrane biofilm reactor.

    Science.gov (United States)

    Ziv-El, Michal C; Rittmann, Bruce E

    2009-01-01

    To evaluate the simultaneous reduction kinetics of the oxidized compounds, we treated nitrate-contaminated groundwater (approximately 9.4 mg-N/L) containing low concentrations of perchlorate (approximately 12.5 microg/L) and saturated with dissolved oxygen (approximately 8 mg/L) in a hydrogen-based membrane biofilm reactor (MBfR). We systematically increased the hydrogen availability and simultaneously varied the surface loading of the oxidized compounds on the biofilm in order to provide a comprehensive, quantitative data set with which to evaluate the relationship between electron donor (H(2)) availability, surface loading of the electron acceptors (oxidized compounds), and simultaneous bioreduction of the electron acceptors. Increasing the H(2) pressure delivered more H(2) gas, and the total H(2) flux increased linearly from approximately 0.04 mg/cm(2)-d for 0.5 psig (0.034 atm) to 0.13 mg/cm(2)-d for 9.5 psig (0.65 atm). This increased rate of H(2) delivery allowed for continued reduction of the acceptors as their surface loading increased. The electron acceptors had a clear hydrogen-utilization order when the availability of hydrogen was limited: oxygen, nitrate, nitrite, and then perchlorate. Spiking the influent with perchlorate or nitrate allowed us to identify the maximum surface loadings that still achieved more than 99.5% reduction of both oxidized contaminants: 0.21 mg NO(3)-N/cm(2)-d and 3.4 microg ClO(4)/cm(2)-d. Both maximum values appear to be controlled by factors other than hydrogen availability.

  11. Solution-reaction Calorimetric Study of Coordination Compounds of Rare Earth Perchlorates with Alanine and Imidazole

    Institute of Scientific and Technical Information of China (English)

    ZHAO, Yan-Ru(赵艳茹); HOU, An-Xin(侯安新); DONG, Jia-Xin(董家新); ZHAO, Shun-Sheng(赵顺省); LIU, Yi(刘义); QU, Song-Sheng(屈松生)

    2004-01-01

    Two coordination compounds of rare earth perchlorates with alanine and imidazole, [RE(Ala)n(Im)(H2O)](ClO4)3(s) (RE=La, n=3; RE=Nd, n=2), have been prepared and characterized. The standard molar enthalpies of reaction for the following two reactions, LaCL·7H2O(s)+3Ala(s)+Im(s)+3NaClO4(s)=[La(Ala).(Im)(H2O)]-(ClO4)3(s)+3NaCl(s)+6H2O(I)(1)and NdCl3·6H2O(s)+2Ala(s)+2Ala(s)+Im(s)+3NaClO4(s)=[Nd(Ala)2(Im)(H2O)]-(ClO4)3(s)+3NaCl(s)+5H2O(l) (2), were determined by solution-reaction calorimetry, at T=298.15 K, as 36.168 ±0.642kJ·mol-1 and 48.590±0.934kJ·mol-1 respectively. From the results and other auxiliary quantities, the standard molar enthalpies of formation of [La(Ala)3(Im)(H2O)](ClO4)3(s) and [Nd(Ala)2(Im)(H2O)] (ClO4)3(s) were derived,△fH(-)m{[La(Ala).(Im)(H2O)](ClO4)3,s}=(-2984.8±1.0)kJ·mol-1 and △fH(-)m{[Nd(Ala).(Im)(H2O)]-(ClO4)3,s}=(-2387.8±0.8)kJ·mol-1, respectively.

  12. 76 FR 39847 - Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation; Final Results of the...

    Science.gov (United States)

    2011-07-07

    ...: Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation, 64 FR 45236 (August 19, 1999). On... Fertilizer Grade Ammonium Nitrate From the Russian Federation, 65 FR 42669 (July 11, 2000) (``Final... International Trade Administration Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation;...

  13. 77 FR 65532 - Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation: Notice of Rescission of...

    Science.gov (United States)

    2012-10-29

    ... International Trade Administration Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation: Notice... the antidumping duty order on solid fertilizer grade ammonium nitrate (ammonium nitrate) from the... Nitrate from Russia: Correction to Notice of Opportunity to Request Administrative Review, 77 FR...

  14. 40 CFR 721.10100 - Dialkyl dimethyl ammonium carbonate (2:1) (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Dialkyl dimethyl ammonium carbonate (2... Specific Chemical Substances § 721.10100 Dialkyl dimethyl ammonium carbonate (2:1) (generic). (a) Chemical... as dialkyl dimethyl ammonium carbonate (2:1) (PMN P-03-716) is subject to reporting under...

  15. cis-Aquabis(2,2′-bipyridine-κ2N,N′fluoridochromium(III bis(perchlorate dihydrate

    Directory of Open Access Journals (Sweden)

    Torben Birk

    2010-02-01

    Full Text Available The title mixed aqua–fluoride complex, [CrF(C10H8N22(H2O](ClO42·2H2O, has been synthesized by aquation of the corresponding difluoride complex using lanthanide(III ions as F− acceptors. The complex crystallizes with a CrIII ion at the center of a distorted octahedral coordination polyhedron with a cis arrangement of ligands. The crystal packing shows a hydrogen-bonding pattern involving water molecules, the coordinated F atom and the perchlorate anions

  16. Kinetics and mechanism of oxidation of glycine by iron(III)-1,10-phenanthroline complex in perchloric acid medium

    Indian Academy of Sciences (India)

    T V N Partha Sarathi; A Kalyan Kumar; K Krishna Kishore; P Vani

    2005-07-01

    Kinetics and mechanism of oxidation of glycine by iron(III)-1,10-phenanthroline complex has been studied in perchloric acid medium. The reaction is first order with respect to iron(III) and glycine. An increase in (phenanthroline) increases the rate, while increase in [H+] decreases the rate. Hence it can be inferred that the reactive species of the substrate is the zwitterionic form and that of the oxidant is [Fe(phen)2(H2O)2]3+. The proposed mechanism leads to the rate law as elucidated.

  17. Anaerobic ammonium oxidation, denitrification and dissimilatory nitrate reduction to ammonium in the East China Sea sediment

    Directory of Open Access Journals (Sweden)

    G. D. Song

    2013-03-01

    Full Text Available Benthic nitrogen transformation pathways were investigated in the sediment of the East China Sea in June of 2010 using the 15N isotope pairing technique. Slurry incubations indicated that denitrification, anammox and dissimilatory nitrate reduction to ammonium (DNRA as well as nitrate release by nitrate storing organisms occurred in the East China Sea sediments. These four processes did not exist independently, the nitrate release therefore diluted the 15N labeling fraction of NO3−, a part of the 15NH4+ derived from DNRA also formed 30N2 via anammox. Therefore current methods of rate calculations led to over and underestimations of anammox and denitrification respectively. Following the procedure outlined in Thampdrup and Dalsgaard (2002, denitrification rates were slightly underestimated by on average 6% without regard to the effect of nitrate release, while this underestimation could be counteracted by the presence of DNRA. On the contrary, anammox rates calculated from 15NO3− experiment were significantly overestimated by 42% without considering nitrate release. In our study this overestimation could only be compensated 14% by taking DNRA into consideration. In a parallel experiment amended with 15NH4+ + 14NO3−, anammox rates were not significantly influenced by DNRA due to the high background of 15NH4+ addition. Excluding measurements in which bioirrigation was present, integrated denitrification rates decreased from 10 to 4 mmol N m−2 d−1 with water depth, while integrated anammox rates increased from 1.5 to 4.0 mmol N m−2 d−1. Consequently, the relative contribution of anammox to the total N-loss increased from 13% at the shallowest site near the Changjiang estuary to 50% at the deepest site on the outer shelf. This study represents the first time in which anammox has been demonstrated to play a significant role in benthic nitrogen cycling in the East China Sea sediment, especially on the outer shelf. N

  18. A Hydrogen Ion-Selective Poly(Vinyl Chloride) Membrane Electrode Based on Calix[4]arene as a Perchlorate Ion-Selective Electrode

    OpenAIRE

    CANEL, Esin; ERDEN, Sevcan; ÖZEL, Ayça DEMİREL; MEMON, Sahahabuddin

    2008-01-01

    A hydrogen ion-selective electrode was prepared using 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetracyanometoxy-calix[4]arene and the possibility of its use as a perchlorate ion-selective electrode was investigated using its characteristic of becoming perchlorate sensitive in acidic regions. The electrode of the optimum characteristic had a composition of 1% ionophore, 66% o-NPOE, and 33% PVC. This electrode exhibited a linear response over the range 1.0 \\times 10-1-1.0 \\times 10-5 M o...

  19. Sources et marché du sulfate d'ammonium Sources of and Market for Ammonium Sulfate

    Directory of Open Access Journals (Sweden)

    Loussouarn C.

    2006-11-01

    Full Text Available Engrais azoté le plus utilisé dans le monde jusqu'en 1970, le sulfate d'ammonium ne représente plus aujourd'hui que 4 % de la fertilisation azotée. Avec une teneur en azote de 21 % seulement, il a été peu à peu remplacé comme engrais universel par des produits plus concentrés, notamment l'urée et le nitrate d'ammonium. Obtenu pour plus de 40 % comme sous-produit dans la synthèse de monomères comme le caprolactame, l'acrylonitrile ou le méthacrylate de méthyle, et pour près de 10 % dans le traitement des gaz de cokerie, sa production dépend largement des développements du marché des fibres synthétiques, et, dans une moindre mesure, de la sidérurgie et de la métallurgie. Dans les pays développés, où la production est essentiellement fatale, le volume du marché est et sera plus fonction de la disponibilité du sulfate d'ammonium que de la demande ou de facteurs de marché; sa consommation ne résidera plus que dans des applications spécifiques pour lesquelles il sera bien adapté. Par contre, l'intérêt croissant pour compenser le déficit en soufre de certains sols, et les qualités agronomiques propres du sulfate d'ammonium laissent entrevoir la possibilité d'un essor de son utilisation dans certaines régions en voie de développernent. Ammonium sulfate was the most worldwide nitrogenous fertilizer used up to 1970. Today, it makes up only 4% of nitrogenous fertilization. With a nitrogen content of only 21%, it has gradually been replaced as a universal fertilizer by more concentrated products, particularly urea and ammonium nitrate. More than 40% of the ammonium sulfate is obtained as a by-product from the synthesis of monomers such as caprolactam, acrylonitrile or methyl methacrylate, and nearly 10% from coking gas processing. Its production depends extensively on the development of the market for synthetic fibers and, to a lesser extent, on the steel and metallurgical industries. In the industrialized countries

  20. Preparation of nanodispersed titania using stabilized ammonium nitrate melts

    KAUST Repository

    Raciulete, Monica

    2010-10-01

    An expedite one-step approach using simple precursors has been proposed to obtain metallic oxide compounds and exemplified by preparation of highly dispersed TiO2. The technique consists in heating to 400500 °C of molten ammonium nitrate stabilized with an organic nitrogen-containing compound (urea, melamine, ammonium oxalate) and containing dissolved metal salt precursor (TiOCl2). The crystallites of the resulting TiO2 demonstrated variable size and shape as a function of stabilizer used. Their activity in photocatalytic oxidation of formic acid also depends on the nature of the stabilizer. The catalysts as-prepared showed high photocatalytic performance, superior to that of the Degussa P25 reference. Nitrogen containing stabilizers play a double role of increasing the process safety and modifying the properties of the solid products. © 2010 Elsevier Inc. All rights reserved.

  1. Synthesis, antimicrobial activity of lamotrigine and its ammonium derivatives

    Indian Academy of Sciences (India)

    Yong Qian; Peng-Cheng Lv; Lei Shi; Rui-Qin Fang; Zhong-Cheng Song; Hai-Liang Zhu

    2009-07-01

    Antiepileptic drug lamotrigine and its thirteen ammonium salt complexes (4a-4m) were synthesized and characterized by IR, elemental analysis, 1H-NMR, and MS spectral methods. Many of the ammonium salts (4a-4m) were first reported. Furthermore, the crystal structure of compound 3 was determined by single crystal X-ray diffraction analysis. All these complexes were tested in vitro for their antibacterial activity (Bacillus subtilis, Staphylococcus aureus, Enterococus faecalis, Escherichia coli, Pseudomonas aeruginosa and Enterobacter cloacae). The results indicated that most of the complexes showed good antibacterial activity against Gram-positive (B. subtilis, S. aureus and S. faecalis), but showed mild, even inactive against Gram-negative bacterial strains.

  2. Recent Advances in the Synthesis of Ammonium-Based Rotaxanes

    Directory of Open Access Journals (Sweden)

    Dominic Thibeault

    2010-05-01

    Full Text Available The number of synthetic methods enabling the preparation of ammonium-based rotaxanes has increased very rapidly in the past ten years. The challenge in the synthesis of rotaxanes results from the rather weak interactions between the ammonium-containing rod and the crown ether macrocycle in the pseudorotaxane structure that rely mostly on O•H hydrogen bonds. Indeed, no strong base or polar solvent that could break up H-bonding can be used during the formation of rotaxanes because the two components will separate as two distinct entities. Moreover, most of the reactions have to be performed at room temperature to favor the formation of pseudorotaxane in solution. These non-trivial prerequisites have been taken into account to develop efficient reaction conditions for the preparation of rotaxanes and those are described in detail along this review.

  3. Thermal stability assessment of anti-explosive ammonium nitrate

    Institute of Scientific and Technical Information of China (English)

    Lijin Shen; Xuguang Wang

    2005-01-01

    The explosivity experiment of anti-explosive ammonium nitrate (AEAN) shows that the explosive characteristic of AEAN is eliminated. The adiabatic decompositions of ammonium nitrate and AEAN were investigated with an accelerating rate calorimeter (ARC). The curves of thermal decomposition temperature and pressure versus time, self-heating rate and pressure versus temperature for two systems were obtained. The kinetic parameters such as apparent activation energy and pre-exponential factor were calculated.The safety of AEAN was analyzed. It was indicated that AEAN has a higher thermal stability than AN. At the same time, it can be shown that the elimination of its explosive characteristic is due to the improvement on the thermal stability of AEAN.

  4. EXCHANGE ADSORPTION EQUILIBRIA OF AMMONIUM ON CATION-VERMICULITE MINERALS

    Institute of Scientific and Technical Information of China (English)

    GUO Yaping; XIE Lianwu; WU Xiaofu

    2006-01-01

    Experiment was designed under different pH and temperature conditions to analysis the NH4+ exchange capacity of Na+-vermiculite, Ca2+-vermiculite and Mg2+-vermiculite clay minerals pre-treated using NaCl, CaCl2 and MgCl2 solutions respectively. The results indicated that the exchange reactions occurred most rapidly at the proceeding 80 minutes and approached to equilibrium by about 120 minutes. The exchange quantity of ammonium on the vermiculite (at initial ammonium concentration of 673mg/L ) varied with pH with a peak value of 28.36mg/g on Na+-vermiculite, 23.01mg/g on Ca2+-vermiculite, 20.14mg/g on Mg2+-vermiculite, 18.04mg/g on natural vermiculite at pH 7. The exchange and adsorption isotherm of NH4+ on cation-vermiculite can be described by Langmuir equation.

  5. Kinetic study of uranium residue dissolution in ammonium carbonate media

    International Nuclear Information System (INIS)

    The purpose of this study was to determine the kinetics of the dissolution of a uranium residue in ammonium carbonate media. The residue is generated in the production of medical isotopes. The effects of parameters, such as varying peroxide and carbonate concentrations, dissolution time as well as temperature on the extraction rate have been separately studied. Results indicate complete dissolution of the residue at 60 deg C, after 30 min, in ammonium carbonate solution enriched with hydrogen peroxide. The yield and rate of uranium extraction were found to increase as a function of both temperature, in the range of 25-60 deg C, and hydrogen peroxide concentration. The extraction process was governed by chemical reaction as the activation energy was found to be 45.5 kJ/mol. The order of reaction with respect to uranium concentration was found to be approximately first order. (author)

  6. Anaerobic ammonium oxidation in a bioreactor treating slaughterhouse wastewater

    Directory of Open Access Journals (Sweden)

    V. Reginatto

    2005-12-01

    Full Text Available Ammonium oxidation was thought to be an exclusively aerobic process; however, as recently described in the literature, it is also possible under anaerobic conditions and this process was named ANAMMOX. This work describes the operation of a system consisting of a denitrifying reactor coupled to a nitrifying reactor used for removal of nitrogen from slaughterhouse wastewater. During operation of the denitrifying reactor an average nitrogen ammonium removal rate of 50 mg/Ld was observed. This biomass was used to seed a second reactor, operated in repeated fed batch mode, fed with synthetic medium specific to the growth of bacteria responsible for the ANAMMOX process. The nitrogen loading rate varied between 33 and 67 mgN/Ld and average nitrogen removal was 95% and 40%, respectively. Results of fluorescence in situ hybridization (FISH confirmed the presence of anammox-like microorganisms in the enriched biomass.

  7. Proton- and ammonium- sensing by histaminergic neurons controlling wakefulness.

    Directory of Open Access Journals (Sweden)

    Yvgenij eYanovsky

    2012-04-01

    Full Text Available Orexinergic and histaminergic neurons in the posterior hypothalamus are involved in the control of arousal. Extracellular levels of acid /CO2 are fundamental physicochemical signals controlling wakefulness and breathing. Acidification excites orexinergic neurons like the chemosensory neurons in the brain stem. Hypercapnia induces c-Fos expression, a marker for increased neuronal activity, in the rat histaminergic tuberomamillary nucleus (TMN, but the mechanisms of this excitation are unknown. Acid-sensing ion channels (ASICs are gated by protons and also by ammonium. Recordings in rat brain slices revealed now that acidification within the physiological range (pH from 7.3 to 7.0 as well as ammonium chloride (5mM excite histaminergic neurons. We detected variable combinations of 4 known types of ASICs in single TMN neurons, along with the pharmacological properties of pH-induced current. At pH 7.0 however, activation of ASICs in TMN neurons was negligible. Block of type I metabotropic glutamate receptors abolished proton- but not ammonium- induced excitation. Mouse TMN neurons were identified within a novel HDC-Cre transgenic reporter mouse line. In contrast to the rat these lacked pH 7.0-induced excitation and showed only a minimal response to the mGluR I agonist DHPG (0.5µM. Ammonium-induced excitation was similar in mouse and rat. Thus glutamate, which is released by glial cells and orexinergic axons amplifies CO2/acid-induced arousal through the recruitment of the histaminergic system in rat but not in mouse. These results are relevant for the understanding of neuronal mechanisms controlling H+/CO2-induced arousal in hepatic encephalopathy and obstructive sleep apnoea. The new HDC-Cre mouse model will be a useful tool for studying the physiological and pathophysiological roles of the histaminergic system.

  8. Synthesis and characterization of ammonium phosphate fertilizers with boron

    OpenAIRE

    ANGELA MAGDA; RODICA PODE; CORNELIA MUNTEAN; MIHAI MEDELEANU; ALEXANDRU POPA

    2010-01-01

    The concentration of boron, an essential micronutrient for plants, presents a narrow range between deficiency and toxicity. In order to provide the boron requirement for plants, and to avoid toxicity problems, boron compounds are mixed with basic fertilizers. Sodium borate pentahydrate was used as a boron source. Ammonium orthophosphates fertilizers with boron were prepared by neutralizing phosphoric acid with ammonia and addition of variable amounts of sodium tetraborate pentahydrate to the ...

  9. Nanomodified vermiculite NMV - a new material for recycling ammonium nitrogen

    Science.gov (United States)

    Rama, Miradije; Laiho, Taina; Eklund, Olav; Lehto, Kirsi; Shebanov, Alex; Smått, Jan-Henrik

    2016-04-01

    Vermiculites ((Mg,Fe,Al)3(Al,Si)4O10(OH)24H2O) are naturally occurring minerals from hydromica group with a high cation exchange capacity and large surface area. Since vermiculite is a hydrated mineral, its structure can be changed with heat. In this study vermiculite samples were heated in an oven until the interlayer distance of them diminished from 14 Å to 11.7 Å. This method for improving vermiculites intake of ammonium ions by heating, is an invention made at the University of Turku. Nanomodified vermiculite (NMV) is able to absorb up to 4.7 wt% of ammonium. NMV can be used as an efficient filter and immobilizer of ammonium in different environments. NMV has been efficiently tested on waste water from a biogas plant, human urine, combustion experiments, industrial chimneys, excrements from farms etc. Ammonium doped vermiculite (ADV) is further developed for fertilizer use. Performed experiments have testified the usability of ADV as a fertilizer. At first step the NMV was processed with the reject water from a biogas plant, were it absorbed NH4+ into the lattice. At second, the ADV was used as nutrient source for garden plants. Geraniums and begonias were used as test plants of the work. Plant growth rate was evaluated based on plant weight. Results showed that significant increase of the growth of geraniums and of begonias were observed when comparing to those cultivations where plants have got normal fertilization. Moreover, ADV has been tested as a fertilizer in greenhouse experiments with spruces and pines. After five months, the weight of the plants that had grown in a substrate containing ADV was 10 times the weight of plants growing in the reference substrate.

  10. Nitrogen loss by anaerobic oxidation of ammonium in rice rhizosphere

    OpenAIRE

    Nie, San'an; Li, Hu; Yang, Xiaoru; Zhang, Zhaoji; Weng, Bosen; Huang, Fuyi; Zhu, Gui-Bing; Zhu, Yong-Guan

    2015-01-01

    Anaerobic oxidation of ammonium (anammox) is recognized as an important process for nitrogen (N) cycling, yet its role in agricultural ecosystems, which are intensively fertilized, remains unclear. In this study, we investigated the presence, activity, functional gene abundance and role of anammox bacteria in rhizosphere and non-rhizosphere paddy soils using catalyzed reporter deposition–fluorescence in situ hybridization, isotope-tracing technique, quantitative PCR assay and 16S rRNA gene cl...

  11. Recovering germanium from coal ash by chlorination with ammonium chloride

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new process of enriching germanium from coal ash was developed. The process involves in mixing the coal ash and ammonium chloride and then roasting the mixture to produce germanium chloride that is then absorbed by dilute hydrochloric acid and hydrolyzed to germanium oxide. The germanium recovery reached to 80.2% at the optimum condition: mass ratio of NH4Cl/coal ash is 0.15, roasting temperature 400℃ and roasting time 90 min.

  12. Ammonium Uptake by Phytoplankton Regulates Nitrification in the Sunlit Ocean

    OpenAIRE

    Smith, Jason M.; Chavez, Francisco P.; Francis, Christopher A.

    2014-01-01

    Nitrification, the microbial oxidation of ammonium to nitrate, is a central part of the nitrogen cycle. In the ocean's surface layer, the process alters the distribution of inorganic nitrogen species available to phytoplankton and produces nitrous oxide. A widely held idea among oceanographers is that nitrification is inhibited by light in the ocean. However, recent evidence that the primary organisms involved in nitrification, the ammonia-oxidizing archaea (AOA), are present and active throu...

  13. Ammonium photo-production by heterocytous cyanobacteria: potentials and constraints.

    Science.gov (United States)

    Grizeau, Dominique; Bui, Lan Anh; Dupré, Catherine; Legrand, Jack

    2016-08-01

    Over the last decades, production of microalgae and cyanobacteria has been developed for several applications, including novel foods, cosmetic ingredients and more recently biofuel. The sustainability of these promising developments can be hindered by some constraints, such as water and nutrient footprints. This review surveys data on N2-fixing cyanobacteria for biomass production and ways to induce and improve the excretion of ammonium within cultures under aerobic conditions. The nitrogenase complex is oxygen sensitive. Nevertheless, nitrogen fixation occurs under oxic conditions due to cyanobacteria-specific characteristics. For instance, in some cyanobacteria, the vegetative cell differentiation in heterocyts provides a well-adapted anaerobic microenvironment for nitrogenase protection. Therefore, cell cultures of oxygenic cyanobacteria have been grown in laboratory and pilot photobioreactors (Dasgupta et al., 2010; Fontes et al., 1987; Moreno et al., 2003; Nayak & Das, 2013). Biomass production under diazotrophic conditions has been shown to be controlled by environmental factors such as light intensity, temperature, aeration rate, and inorganic carbon concentration, also, more specifically, by the concentration of dissolved oxygen in the culture medium. Currently, there is little information regarding the production of extracellular ammonium by heterocytous cyanobacteria. This review compares the available data on maximum ammonium concentrations and analyses the specific rate production in cultures grown as free or immobilized filamentous cyanobacteria. Extracellular production of ammonium could be coupled, as suggested by recent research on non-diazotrophic cyanobacteria, to that of other high value metabolites. There is little information available regarding the possibility for using diazotrophic cyanobacteria as cellular factories may be in regard of the constraints due to nitrogen fixation. PMID:25613641

  14. Hibiscus sabdariffa Affects Ammonium Chloride-Induced Hyperammonemic Rats

    OpenAIRE

    Subramanian, P.; M. Mohamed Essa

    2007-01-01

    Hibiscus sabdariffa (HS) is an edible medicinal plant, indigenous to India, China and Thailand and is used in Ayurveda and traditional medicine. Alcoholic extract of HS leaves (HSEt) was studied for its anti-hyperammonemic and antioxidant effects in brain tissues of ammonium chloride-induced hyperammonemic rats. Oral administration of HSEt (250 mg kg−1 body weight) significantly normalizes the levels of ammonia, urea, uric acid, creatinine and non-protein nitrogen in the blood. HSEt significa...

  15. Subsurface ammonium maxima in northern Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Satyanarayana, D.; Sahu, S.D.; Panigrahy, P.K.; Sarma, V.V.; Suguna, C.

    . Inorganic phosphate was determined by the method of Murphy & Riley (1962), nitrite by the method of Bendschneider & Robinson (1952) and nitrate by the method of Morris & Riley (1963) as modified by Grasshoff (1964). Ammonium was determined by indophenol.... Further, its distribution in the water column showed no definite vertical trend as reported earlier in the other open oceans (Menzel & Spaeth, 1962; Sagi, 1966). However, in the northern Bay of Bengal two prominent maxima, one in the euphotic zone near...

  16. Alicyclic ammonium ionic liquids as lithium battery electrolytes A review

    OpenAIRE

    Puga, A.V.

    2013-01-01

    Ionic liquids are reasonable alternatives to electrolytes used in energy storage devices, such as lithium batteries, both lithium-ion and lithium-metal, given the safety advantages they provide. This is due to the favourable properties they often possess, mainly non­flammability and non­volatility. Candidates with alicyclic ammonium cations exhibit high electrochemical stabilities, especially towards lithium, a unique feature which enables the fabrication of reversible lithium-metal batteries...

  17. Nitrogen addition regulates soil nematode community composition through ammonium suppression.

    Directory of Open Access Journals (Sweden)

    Cunzheng Wei

    Full Text Available Nitrogen (N enrichment resulting from anthropogenic activities has greatly changed the composition and functioning of soil communities. Nematodes are one of the most abundant and diverse groups of soil organisms, and they occupy key trophic positions in the soil detritus food web. Nematodes have therefore been proposed as useful indicators for shifts in soil ecosystem functioning under N enrichment. Here, we monitored temporal dynamics of the soil nematode community using a multi-level N addition experiment in an Inner Mongolia grassland. Measurements were made three years after the start of the experiment. We used structural equation modeling (SEM to explore the mechanisms regulating nematode responses to N enrichment. Across the N enrichment gradient, significant reductions in total nematode abundance, diversity (H' and taxonomic richness, maturity index (MI, and the abundance of root herbivores, fungivores and omnivores-predators were found in August. Root herbivores recovered in September, contributing to the temporal variation of total nematode abundance across the N gradient. Bacterivores showed a hump-shaped relationship with N addition rate, both in August and September. Ammonium concentration was negatively correlated with the abundance of total and herbivorous nematodes in August, but not in September. Ammonium suppression explained 61% of the variation in nematode richness and 43% of the variation in nematode trophic group composition. Ammonium toxicity may occur when herbivorous nematodes feed on root fluid, providing a possible explanation for the negative relationship between herbivorous nematodes and ammonium concentration in August. We found a significantly positive relationship between fungivores and fungal phospholipid fatty acids (PLFA, suggesting bottom-up control of fungivores. No such relationship was found between bacterivorous nematodes and bacterial PLFA. Our findings contribute to the understanding of effects of N

  18. Study of stripping cristallization processus of AUC with ammonium carbonate

    International Nuclear Information System (INIS)

    This study is concerned with direct crystallization of ammonium uranyl carbonate (AUC) from a uranium loaded organic phase (30% TBP in kerosene), with ammonium carbonate (NH4)2CO3. The effects of operating conditions ((NH4)2CO3 concentration, flow-ratio, residence time, temperature) on the physical properties of AUC crystals (particle size distribution, specific surface, density...) are reported. All products were identified (both by chemical analysis, X-Ray diffraction) as being ammonium uranyl carbonate crystals (AUC). The results show that a high phase ratio and (NH4)2CO3 concentration favor the formation of fine AUC grains and aggregates. This is due mainly to the high concentration of NH+4 in the system which leads to a high solution supersaturation and consequently to a rapid formation rate of crystal (germination). The reverse phenomenon is observed at low phase ratio and (NH4)2CO3 concentration, where germination and crystal growth are slow and the product is mainly monocrystal. In the intermediate range, a mixture of polycrystal and aggregates is obtained. Residence and temperature are also shown to have an effect on the processes (the effect of time being more important than temperature). In the course of this study a bench-scale stripper-crystallizer was developped and operated successfully. (author). tables, graphs

  19. Extraction Factor Of Pure Ammonium Paratungstate From Tungsten Scraps

    Directory of Open Access Journals (Sweden)

    Pee J.-H.

    2015-06-01

    Full Text Available Typical oxidation process of tungsten scraps was modified by the rotary kiln with oxygen burner to increase the oxidation rate of tungsten scraps. Also to accelerate the solubility of solid oxidized products, the hydrothermal reflux method was adapted. By heating tungsten scraps in rotary kiln with oxygen burner at around 900° for 2hrs, the scraps was oxidized completely. Then oxidized products (WO3 and CoWO4 was fully dissolved in the solution of NaOH by hydrothermal reflux method at 150° for 2hrs. The dissolution rate of oxidized products was increased with increasing the reaction temperature and concentration of NaOH. And then CaWO4 and H2WO4 could be generated from the aqueous sodium tungstate solution. Ammonium paratungstate (APT also could be produced from tungstic acid using by aqueous ammonium solution. The morphologies (cubic and plate types of APT was controlled by the stirring process of purified solution of ammonium paratungstate.

  20. Structural basis for Mep2 ammonium transceptor activation by phosphorylation.

    Science.gov (United States)

    van den Berg, Bert; Chembath, Anupama; Jefferies, Damien; Basle, Arnaud; Khalid, Syma; Rutherford, Julian C

    2016-04-18

    Mep2 proteins are fungal transceptors that play an important role as ammonium sensors in fungal development. Mep2 activity is tightly regulated by phosphorylation, but how this is achieved at the molecular level is not clear. Here we report X-ray crystal structures of the Mep2 orthologues from Saccharomyces cerevisiae and Candida albicans and show that under nitrogen-sufficient conditions the transporters are not phosphorylated and present in closed, inactive conformations. Relative to the open bacterial ammonium transporters, non-phosphorylated Mep2 exhibits shifts in cytoplasmic loops and the C-terminal region (CTR) to occlude the cytoplasmic exit of the channel and to interact with His2 of the twin-His motif. The phosphorylation site in the CTR is solvent accessible and located in a negatively charged pocket ∼30 Å away from the channel exit. The crystal structure of phosphorylation-mimicking Mep2 variants from C. albicans show large conformational changes in a conserved and functionally important region of the CTR. The results allow us to propose a model for regulation of eukaryotic ammonium transport by phosphorylation.

  1. Increasing wheat production while decreasing nitrogen losses from ammonium bicarbonate

    International Nuclear Information System (INIS)

    The objectives of a 4-year field experiment were i) to investigate the effects of rate and timing of application of ammonium bicarbonate on N-uptake efficiency by irrigated winter wheat, ii) to determine the fate of fertilizer N in wheat followed by maize, and iii) to study nitrate dynamics in the soil after N-fertilizer application to evaluate groundwater pollution by leaching. Nitrogen-application rates significantly affected wheat grain yields and straw dry matter. Grain yields were higher with 150 than with 225 kg N ha-1, whereas the highest fractional recoveries of N from ammonium bicarbonate occurred with 75 kg N ha-1 (38.5% in 1994-95 and 33.5% in 1996-97). On the basis of grain yield, N recovery and soil-N balance, ammonium bicarbonate at 150 kg N ha-1, was the optimum rate, when applied basally and as a top dressing to wheat. Subsequent yields of maize stover and grain were affected by N applied to the wheat, suggesting that fertilizer recommendations, in terms of rate and timing, should be made on the basis of effects on the cropping rotation as a whole. Water-holding capacity of the soil was poor, therefore large applications of N are likely to cause nitrate pollution of ground water. (author)

  2. Study of the ion-channel behavior on glassy carbon electrode supported bilayer lipid membranes stimulated by perchlorate anion

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhiquan; Shi, Jun; Huang, Weimin, E-mail: huangwm@jlu.edu.cn

    2015-10-01

    In this paper, a kind of didodecyldimethylammonium bromide (DDAB) layer membranes was supported on a glassy carbon electrode (GCE). We studied the ion channel behavior of the supported bilayer lipid membrane by scanning electrochemical microscopy (SCEM) in tris(2,2′-bipyridine) ruthenium(II) solution. Perchlorate anion was used as a presence of stimulus and ruthenium(II) complex cations as the probing ions for the measurement of SECM, the lipid membrane channel was opened and exhibited the behavior of distinct SECM positive feedback curve. The channel was in a closed state in the absence of perchlorate anions while reflected the behavior of SECM negative feedback curve. The rates of electron transfer reaction in the lipid membranes surface were detected and it was dependant on the potential of SECM. - Highlights: • The rates of electron transfer reaction in the lipid membranes surface were detected. • Dynamic investigations of ion-channel behavior of supported bilayer lipid membranes by scanning electrochemical microscopy • A novel way to explore the interaction between molecules and supported bilayer lipid membranes.

  3. Crystal structure of barium perchlorate anhydrate, Ba(ClO42, from laboratory X-ray powder data

    Directory of Open Access Journals (Sweden)

    Jeonghoo H. Lee

    2015-06-01

    Full Text Available The previously unknown crystal structure of barium perchlorate anhydrate, determined and refined from laboratory X-ray powder diffraction data, represents a new structure type. The title compound was obtained by heating hydrated barium perchlorate [Ba(ClO42·xH2O] at 423 K in vacuo for 6 h. It crystallizes in the orthorhombic space group Fddd. The asymmetric unit contains one Ba (site symmetry 222 on special position 8a, one Cl (site symmetry 2 on special position 16f and two O sites (on general positions 32h. The structure can be described as a three-dimensional polyhedral network resulting from the corner- and edge-sharing of BaO12 polyhedra and ClO4 tetrahedra. Each BaO12 polyhedron shares corners with eight ClO4 tetrahedra, and edges with two ClO4 tetrahedra. Each ClO4 tetrahedron shares corners with four BaO12 polyhedra, and an edge with the other BaO12 polyhedron.

  4. Concurrence of Anaerobic Ammonium Oxidation and Organotrophic Denitrification in Presence of p-Cresol.

    Science.gov (United States)

    González-Blanco, G; Cervantes, F J; Beristain-Cardoso, R; Gómez, J

    2015-08-01

    This study was carried out to evaluate the capacity of anaerobic granular sludge for oxidizing ammonium and p-cresol with nitrate as terminal electron acceptor. Kinetics for the anaerobic oxidation of ammonium and p-cresol is described in this paper. The phenolic compound was very efficiently consumed, achieving 65 % of mineralization. Ammonium and nitrate were also consumed at 83 and 92 %, respectively, being the main product N2. Anaerobic ammonium oxidation was promoted owing to accumulation of nitrite, and it allowed the synergy of anaerobic ammonium oxidation and organotrophic denitrification for the simultaneous removal of ammonium, nitrate, and p-cresol. A carbonaceous intermediate partially identified was transiently accumulated, and it transitorily truncated the respiratory process of denitrification. These experimental results might be considered for defining strategies in order to remove nitrate, ammonium, and phenolic compounds from wastewaters. PMID:26062920

  5. Soil, plant, and terrain effects on natural perchlorate distribution in a desert landscape

    Science.gov (United States)

    Andraski, Brian J.; Jackson, W.A.; Welborn, Toby L.; Böhlke, John Karl; Sevanthi, Ritesh; Stonestrom, David A.

    2014-01-01

    Perchlorate (ClO4−) is a contaminant that occurs naturally throughout the world, but little is known about its distribution and interactions in terrestrial ecosystems. The objectives of this Amargosa Desert, Nevada study were to determine (i) the local-scale distribution of shallow-soil (0–30 cm) ClO4− with respect to shrub proximity (far and near) in three geomorphic settings (shoulder slope, footslope, and valley floor); (ii) the importance of soil, plant, and terrain variables on the hillslope-distribution of shallow-soil and creosote bush [Larrea tridentata (Sessé & Moc. ex DC.) Coville] ClO4−; and (iii) atmospheric (wet plus dry, including dust) deposition of ClO4− in relation to soil and plant reservoirs and cycling. Soil ClO4− ranged from 0.3 to 5.0 μg kg−1. Within settings, valley floor ClO4− was 17× less near shrubs due in part to enhanced leaching, whereas shoulder and footslope values were ∼2× greater near shrubs. Hillslope regression models (soil, R2 = 0.42; leaf, R2 = 0.74) identified topographic and soil effects on ClO4− deposition, transport, and cycling. Selective plant uptake, bioaccumulation, and soil enrichment were evidenced by leaf ClO4− concentrations and Cl−/ClO4− molar ratios that were ∼8000× greater and 40× less, respectively, than soil values. Atmospheric deposition ClO4− flux was 343 mg ha−1 yr−1, ∼10× that for published southwestern wet-deposition fluxes. Creosote bush canopy ClO4− (1310 mg ha−1) was identified as a previously unrecognized but important and active reservoir. Nitrate δ18O analyses of atmospheric deposition and soil supported the leaf-cycled–ClO4− input hypothesis. This study provides basic data on ClO4− distribution and cycling that are pertinent to the assessment of environmental impacts in desert ecosystems and broadly transferable to anthropogenically contaminated systems.

  6. Use of starch and potato peel waste for perchlorate bioreduction in water.

    Science.gov (United States)

    Okeke, Benedict C; Frankenberger, William T

    2005-07-15

    The cost of carbon substrates for microbial reduction of perchlorate (ClO(4)(-)) is central to the success and competitiveness of a sustainable bioremediation strategy for ClO(4)(-). This study explored the potential application of starch in combination with an amylolytic bacterial consortia and potato peel waste for ClO(4)(-) bioreduction. We obtained a potent amylolytic bacterial consortium that consisted of a Citrobacter sp. S4, Streptomyces sp. S2, Flavobacterium sp. S6, Pseudoxanthomonas sp. S5, Streptomyces sp. S7, and an Aeromonas sp. S8 identified by 16S rDNA sequencing. ClO(4)(-) concentration substantially decreased in purified starch medium inoculated with the amylolytic bacterial consortium and Dechlorosoma sp. perclace. Potato peel waste supported ClO(4)(-) reduction by perclace with the rate of ClO(4)(-) reduction being dependent on the amount of potato peels. Over 90% ClO(4)(-) removal was achieved in 4 days in a single time point experiment with 2% (w/v) potato peels waste. ClO(4)(-) reduction in a non-sterile 0.5% potato peel media inoculated with perclace occurred with an initial concentration of 10.14+/-0.04 mg L(-1) to 2.87+/-0.4 mg L(-1) (71.7% reduction) within 5 days. ClO(4)(-) was not detected in the cultures in 6 days. In a non-sterile 0.5% potato media without perclace, ClO(4)(-) depletion occurred slowly from an initial value of 9.99+/-0.15 mg L(-1) to 6.33+/-0.43 mg L(-1) (36.63% reduction) in 5 days. Thereafter, ClO(4)(-) was rapidly degraded achieving 77.1% reduction in 7 days and not detected in 9 days. No susbstantial reduction of ClO(4)(-) was observed in the sterile potato peel media without perclace in 7 days. Redox potential of the potato peel cultures was favorable for ClO(4)(-) reduction, decreasing to as low as -294 mV in 24 h. Sugar levels remained very low in cultures effectively reducing ClO(4)(-) and was substantially higher in sterilized controls. Our results indicate that potato peel waste in combination with amylolytic

  7. Experimental evidence for supercooled brines, viscous liquids, and low temperature perchlorate glasses on Mars

    Science.gov (United States)

    Toner, J.; Catling, D. C.; Light, B.

    2013-12-01

    The presence of liquid water on the cold and dry surface of Mars is possible where concentrated salt solutions lower the freezing point of water. The eutectic temperature is the maximum equilibrium freezing point depression possible for a given salt solution, which ranges from near 0°C for carbonates and sulfates, to as low as -75°C for perchlorates. Although eutectic temperatures suggest a lower temperature limit for liquid water on Mars, salt solutions will typically supercool below their eutectic before crystallization occurs. We report on results investigating the magnitude of supercooling and its variation with salt composition and concentration for pure salt solutions and saturated soil solutions of MgSO4, MgCl2, NaCl, NaClO4, Mg(ClO4)2, and Ca(ClO4)2. We measured supercooling by monitoring solution temperatures during slow cooling and warming experiments. Our results indicate that supercooling is pervasive. Slowly cooled MgSO4, MgCl2, NaCl, and NaClO4 solutions typically supercool 5-15°C below their eutectic temperature before crystallizing. The addition of soil to these salt solutions has a variable effect on supercooling. Relative to the pure salt solutions, supercooling decreases in MgSO4 soil solutions, increases in MgCl2 soil solutions, and is similar in NaCl and NaClO4 soil solutions. Supercooling in MgSO4, MgCl2, NaCl, and NaClO4 solutions could marginally extend the duration of liquid water during relatively warm daytime temperatures in the Martian summer. Remarkably, we found that Mg(ClO4)2 and Ca(ClO4)2 solutions never crystallize during slow cooling, but remain in a supercooled, liquid state until forming an amorphous glass near -120°C. Even if soil is added to the solutions, which will induce crystallization in most salt solutions, a glass still forms during cooling. The large supercooling effect in Mg(ClO4)2 and Ca(ClO4)2 solutions has the potential to prevent water from freezing over diurnal and possibly annual cycles on Mars. Glasses are

  8. Use of starch and potato peel waste for perchlorate bioreduction in water.

    Science.gov (United States)

    Okeke, Benedict C; Frankenberger, William T

    2005-07-15

    The cost of carbon substrates for microbial reduction of perchlorate (ClO(4)(-)) is central to the success and competitiveness of a sustainable bioremediation strategy for ClO(4)(-). This study explored the potential application of starch in combination with an amylolytic bacterial consortia and potato peel waste for ClO(4)(-) bioreduction. We obtained a potent amylolytic bacterial consortium that consisted of a Citrobacter sp. S4, Streptomyces sp. S2, Flavobacterium sp. S6, Pseudoxanthomonas sp. S5, Streptomyces sp. S7, and an Aeromonas sp. S8 identified by 16S rDNA sequencing. ClO(4)(-) concentration substantially decreased in purified starch medium inoculated with the amylolytic bacterial consortium and Dechlorosoma sp. perclace. Potato peel waste supported ClO(4)(-) reduction by perclace with the rate of ClO(4)(-) reduction being dependent on the amount of potato peels. Over 90% ClO(4)(-) removal was achieved in 4 days in a single time point experiment with 2% (w/v) potato peels waste. ClO(4)(-) reduction in a non-sterile 0.5% potato peel media inoculated with perclace occurred with an initial concentration of 10.14+/-0.04 mg L(-1) to 2.87+/-0.4 mg L(-1) (71.7% reduction) within 5 days. ClO(4)(-) was not detected in the cultures in 6 days. In a non-sterile 0.5% potato media without perclace, ClO(4)(-) depletion occurred slowly from an initial value of 9.99+/-0.15 mg L(-1) to 6.33+/-0.43 mg L(-1) (36.63% reduction) in 5 days. Thereafter, ClO(4)(-) was rapidly degraded achieving 77.1% reduction in 7 days and not detected in 9 days. No susbstantial reduction of ClO(4)(-) was observed in the sterile potato peel media without perclace in 7 days. Redox potential of the potato peel cultures was favorable for ClO(4)(-) reduction, decreasing to as low as -294 mV in 24 h. Sugar levels remained very low in cultures effectively reducing ClO(4)(-) and was substantially higher in sterilized controls. Our results indicate that potato peel waste in combination with amylolytic

  9. ANALYSIS OF THE KINETICS OF SOLVOLYSIS OF P-NITROPHENYLSULFONYLMETHYL PERCHLORATE IN BINARY ALCOHOLIC MIXTURES IN TERMS OF THE THERMODYNAMIC PROPERTIES OF THE SOLVENT MIXTURES

    NARCIS (Netherlands)

    WIJNEN, JW; ENGBERTS, JBFN; BLANDAMER, MJ

    1993-01-01

    Rate constants are reported for the solvolysis of p-nitrophenylsulfonylmethyl perchlorate in binary ethanolic and methanolic mixtures at 298.2 K. Co-solvents include hydrocarbons, chlorinated hydrocarbons and 1,4-dioxane. The kinetic data are examined in terms of the effect of decreasing mole fracti

  10. Ferric Perchlorate Catalyzed One-pot Synthesis of 1,2,3,4-Tetrahydro-2-pyrimidinones and -thiones:an Expedient Protocol for the Biginelli Reaction

    Institute of Scientific and Technical Information of China (English)

    HERAVI,Majid Momahed; BEHBAHANI,Farahnaz Kargar OSKOOIE; Hossien Abdi

    2008-01-01

    An efficient synthesis of 1,2,3,4-tetrahydro-2-pyrimidinones and -thiones using ferric perchlorate as the catalyst from an aldehyde, ethyl acetoacetate, and urea or thiourea in acetonitrile was described. Compared to the classical Biginelli reaction conditions, this new method consistently has the advantage of full catalysis, good yields and short reaction time.

  11. EFFECTS OF LOW DOSE MIXTURES OF PCB126 AND PERCHLORATE ON THE HYPTHALAMIC-PITUITARY-THYROID (HPT) AXIS IN THE MALE RAT.

    Science.gov (United States)

    Perchlorate (ClO4) and 3,3',4,4',5-pentachlorobiphenyl (PCB126) are environmental contaminants known to disturb thyroid hormone homeostasis by well defined modes of action that lead to hypothyroidism in the rat. PCB126 increases phase II conjugation of T4 (T4-glucuronide) by indu...

  12. Influence of heterogeneous ammonium availability on bacterial community structure and the expression of nitrogen fixation and ammonium transporter genes during in situ bioremediation of uranium-contaminated groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Mouser, P.J.; N' Guessan, A.L.; Elifantz, H.; Holmes, D.E.; Williams, K.H.; Wilkins, M.J.; Long, P.E.; Lovley, D.R.

    2009-04-01

    The impact of ammonium availability on microbial community structure and the physiological status and activity of Geobacter species during in situ bioremediation of uranium-contaminated groundwater was evaluated. Ammonium concentrations varied by as much as two orders of magnitude (<4 to 400 {micro}M) across the study site. Analysis of 16S rRNA gene sequences suggested that ammonium influenced the composition of the microbial community prior to acetate addition with Rhodoferax species predominating over Geobacter species at the site with the highest ammonium, and Dechloromonas species dominating at sites with lowest ammonium. However, once acetate was added, and dissimilatory metal reduction was stimulated, Geobacter species became the predominant organisms at all locations. Rates of U(VI) reduction appeared to be more related to the concentration of acetate that was delivered to each location rather than the amount of ammonium available in the groundwater. In situ mRNA transcript abundance of the nitrogen fixation gene, nifD, and the ammonium importer gene, amtB, in Geobacter species indicated that ammonium was the primary source of nitrogen during in situ uranium reduction, and that the abundance of amtB transcripts was inversely correlated to ammonium levels across all sites examined. These results suggest that nifD and amtB expression by subsurface Geobacter species are closely regulated in response to ammonium availability to ensure an adequate supply of nitrogen while conserving cell resources. Thus, quantifying nifD and amtB expression appears to be a useful approach for monitoring the nitrogen-related physiological status of Geobacter species in subsurface environments during bioremediation. This study also emphasizes the need for more detailed analysis of geochemical/physiological interactions at the field scale, in order to adequately model subsurface microbial processes.

  13. Changes in gastric sodium-iodide symporter (NIS) activity are associated with differences in thyroid gland sensitivity to perchlorate during metamorphosis.

    Science.gov (United States)

    Carr, James A; Murali, Sharanya; Hu, Fang; Goleman, Wanda L; Carr, Deborah L; Smith, Ernest E; Wages, Mike

    2015-08-01

    We investigated stage-dependent changes in sensitivity of the thyroid gland to perchlorate during development of African clawed frog tadpoles (Xenopus laevis) in relation to non-thyroidal iodide transporting tissues. Perchlorate-induced increases in thyroid follicle cell size and colloid depletion were blunted when exposures began at Nieuwkoop-Faber (NF) stage 55 compared to when exposures began at NF stages 49 or 1-10. To determine if the development of other iodide transporting tissues may contribute to this difference we first examined which tissues expressed transcripts for the sodium dependent iodide symporter (NIS). RT-PCR analysis revealed that NIS was expressed in stomach and small intestine in addition to the thyroid gland of X. laevis tadpoles. NIS mRNA was not detected in lung, kidney, skin, gill, muscle, heart or liver. Perchlorate sensitive (125)I uptake was found in stomach, lung, kidney, gill, and small intestine but not muscle, liver, or heart. Perchlorate-sensitive (125)I uptake by stomach was 6-10 times greater than in any other non-thyroidal tissue in tadpoles. While NF stage 49 tadpoles exhibited perchlorate-sensitive uptake in stomach it was roughly 4-fold less than that observed in NF stage 55 tadpoles. Although abundance of NIS gene transcripts was greater in stomachs from NF stage 55 compared to NF stage 49 tadpoles this difference was not statistically significant. We conclude that gastric iodide uptake increases between NF stages 49 and 55, possibly due to post-translational changes in NIS glycosylation or trafficking within gastric mucosal cells. These developmental changes in gastric NIS gene expression may affect iodide availability to the thyroid gland.

  14. Regeneration of clinoptilolite zeolite used for the ammonium removal

    International Nuclear Information System (INIS)

    The use of zeolites has been increased in the last years with different applications and with a great boom in the environmental area, but a little had been make about the regeneration of such zeolites. The presence of nitrogen-ammonia in water may cause serious pollution problems since it results to be toxic for fishes and other aquatic life forms, also it provokes the algae growing. The natural clinoptilolite contains interchangeable ions such as the sodium (Na+), potassium (K+), magnesium (Mg2+) and calcium (Ca2+) in different proportions depending on the mineral origin When the zeolite is upgraded to its sodium form, the cation exchange capacity and the preference by the nitrogen-ammonia are increased, allowing the reversible process of sorption. In this work it was proposed the regeneration to its sodium form about the ammonia clinoptilolite zeolite. The natural mineral was characterized using the methods such as: X-ray diffraction, Infrared spectroscopy, Thermal gravimetric analysis and surface area. The results show that the ammonium sorption was between 95% and 98.7% such an ambient temperature as a flow back. the zeolite was regenerated approximately from 60% in the first cycle up to 97% in the last cycle at flow back temperature and of 59.2% up to 96.9% at ambient temperature, it was not presented any significant effect which could be attributed to the temperature. During the exchange process, the cations present in the natural zeolite were exchanged with the ammonium ions, this process was not completed due to that retained ammonium quantity was major that of the desorpted ions, what shows that in addition of ion exchange, another type of sorption process exists. (Author)

  15. Theoretical Study of Energetic Complexes (Ⅲ): Bis-(5-nitro-2Htetrazolato-N2)tetraammine Cobalt(Ⅲ) Perchlorate (BNCP) and Its Transition Metal (Ni/Fe/Cu/Zn) Perchlorate Analogues

    Institute of Scientific and Technical Information of China (English)

    尚静; 张建国; 张同来; 黄辉胜; 张绍文; 舒远杰

    2012-01-01

    The geometric conformation and electronic structure of bis-(5-nitro-2H-tetrazolato-N2)tetraammine cobalt(Ⅲ) perchlorate and its Ni/Fe/Cu/Zn analogues are studied under the TPSS (Tao-Perdew-Staroverov-Scuseria) levels of density functional theory in order to throw light on the relationship between their energy gaps and impact sensitivity While the perchlorate ions are coordinated with the copper cation, which is different from the other four compounds NBO (Natural bond orbital) analyses indicated that the metal-ligand interaction in the Co complex is covalent, while the others are ionic. The analysis of the electrostatic potential demonstrated that the O atoms from the nitro-tetrazole ring and perchlorate were primarily negative, while the other atoms were positive. The study was also conducted to gain a better understanding of the correlation of the energy gap and impact sensitivity.

  16. The Properties of Ammonium Dinitramine (ADN): Part 2: Melt Casting

    Science.gov (United States)

    Hahma, A.; Edvinsson, H.; Östmark, H.

    2010-04-01

    A melt casting technique for ammonium dinitramine (ADN) and ADN/aluminum was developed. ADN proved relatively easy to cast, when 1% of magnesium oxide was used as a stabilizer and crystallization kernels. Densities of ADN/MgO 99/1 were 92 to 97% of theoretical mean density (TMD) and those of ADN/Al/MgO 64/35/1 were between 95 and 99% of TMD. Sedimentation of Al in the melt was prevented and the particle wetting was ensured by selecting a suitable particle size for Al. No gelling agents or other additives were used. The casting process and factors influencing it are discussed.

  17. Ammonium diamminesilver(I bis(5-chloro-2-hydroxybenzenesulfonate trihydrate

    Directory of Open Access Journals (Sweden)

    Zhao-Peng Deng

    2012-02-01

    Full Text Available The reaction of silver nitrate with 5-chloro-2-hydroxybenzenesulfonic acid in the presence of ammonia yielded the title salt, (NH4[Ag(NH32](C6H4ClO4S2·3H2O. The AgI ion shows linear coordination [N—Ag—N = 175.2 (1 °]. The ammonium and diamminesilver cations, the benzenesulfonate anion and the lattice water molecules interact through an intricate network of N—H...O and O—H...O hydrogen bonds to form a three-dimensional network.

  18. Experimental study of the detonation of technical grade ammonium nitrate

    Science.gov (United States)

    Presles, Henri-Noël; Vidal, Pierre; Khasainov, Boris

    2009-11-01

    The detonation of technical grade ammonium nitrate at the density ρ=0.666 g/cm confined in PVC and steel tubes was experimentally studied. The results show that the detonation is self-sustained and steady in steel tubes with diameter as small as 12 mm. Critical detonation diameter lies between 8 and 12 mm in 2 mm thick steel tubes and between 55 and 81 mm in PVC tubes. These values testify a strong detonation sensitivity of this product. To cite this article: H.-N. Presles et al., C. R. Mecanique 337 (2009).

  19. Aluminum-silicates flotation with quaternary ammonium salts

    Institute of Scientific and Technical Information of China (English)

    王毓华; 胡岳华; 陈湘清

    2003-01-01

    The zeta potential measurements show that the flotation separation of diaspore from kaolinite, illite and pyrophyllite could be achieved in the range of pH 46.5 with cationic collectors. A special quaternary ammonium salts(DTAL) shows better selectivity than that the dodecyl amine(DDA) does for the flotation of three silicates. The closed-circuit flotation results show that the reverse flotation de-silicate can be achieved with DTAL as collector, a new inorganic reagent(SFL) as depressant and MIBC as frother to obtain a bauxite concentrate m(Al2O3)/m(SiO2)>10, Al2O3 recovery>86%).

  20. Ammonium sulphate on maize crops under no tillage

    OpenAIRE

    Maria Anita Gonçalves da Silva; Anny Rosi Mannigel; Antonio Saraiva Muniz; Simone Maria Altoé Porto; Marlene Estevão Marchetti; Antonio Nolla; Rosemary Marques de Almeida Bertani

    2012-01-01

    The objectives of this work were to evaluate the management of N and S (as ammonium sulphate) fertilization under no-tillage system on the components of maize productivity and on N and S accumulation in the crop, as well as to evaluate the minimum value of the Nitrogen Sufficiency Index (NSI 0.95) as an indicator for side dressing requirements. The experiment had a completely randomized block design with six treatments and four replications carried out in Red Latosol dystrophic soil (Hapludox...

  1. Further laboratory and theoretical investigations of ammonium dinitramide

    Energy Technology Data Exchange (ETDEWEB)

    Tulis, A.J.; Snelson, A. [IIT Research Institut, Chicago (United States); Heberlein, C.; Patel, D.L. [U.S. Army Cecom RD et E Center, NVESD (United States)

    1996-12-31

    Hydrogen and deuterated ammonium dinitramide have been vaporized under high vacuum and the IR matrix isolation spectra of the decomposition products obtained. Tentative vibration assignments have been made for HN(NO{sub 2}){sub 2} and DN(NO{sub 2}){sub 2} assuming a symmetrical non-planar structure in which the H or D is bonded to the central nitrogen atom. Other structures are also possible. Ab initio calculations have been made for the various structural isomers of hydrogen dinitramide. Vibration frequencies calculated for the hydrogenated and deuterated species are compared with the experimental values with the object of identifying the molecules` structure. (authors) 3 refs.

  2. Surface energy and crystallization phenomena of ammonium dinitramide

    Energy Technology Data Exchange (ETDEWEB)

    Teipel, Ulrich; Heintz, Thomas [Fraunhofer-Institut fuer Chemische Technologie (ICT), PO Box 1240, D-76318 Pfinztal (Germany)

    2005-12-01

    Ammonium dinitramide (ADN) was characterized during recrystallization from the melt. The surface tension of molten ADN at 97 C was measured to be 89 mN/m. The wetting angles between molten ADN and different solid surfaces (polytetrafluoroethylene, glass, steel, and aluminum) were determined. The wettability depends on the surface tension of molten ADN, the free surface energy of the solid surfaces and the interfacial tension between the solid and liquid. Observations of the recrystallization behavior of molten ADN showed that nucleation does not occur, even at super cooling rates of 70 K. Crystallization can be initiated by the application of seed crystals. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  3. Molecular recognition of organic ammonium ions in solution using synthetic receptors

    Directory of Open Access Journals (Sweden)

    Andreas Späth

    2010-04-01

    Full Text Available Ammonium ions are ubiquitous in chemistry and molecular biology. Considerable efforts have been undertaken to develop synthetic receptors for their selective molecular recognition. The type of host compounds for organic ammonium ion binding span a wide range from crown ethers to calixarenes to metal complexes. Typical intermolecular interactions are hydrogen bonds, electrostatic and cation–π interactions, hydrophobic interactions or reversible covalent bond formation. In this review we discuss the different classes of synthetic receptors for organic ammonium ion recognition and illustrate the scope and limitations of each class with selected examples from the recent literature. The molecular recognition of ammonium ions in amino acids is included and the enantioselective binding of chiral ammonium ions by synthetic receptors is also covered. In our conclusion we compare the strengths and weaknesses of the different types of ammonium ion receptors which may help to select the best approach for specific applications.

  4. The effect of the ammonium ion on activated-sludge settling properties

    DEFF Research Database (Denmark)

    Novak, John Thomas

    2001-01-01

    High levels of sodium in wastewater have been found to be detrimental to activated-sludge. settling and dewatering. Another potentially troublesome monovalent cation in activated-sludge systems is the ammonium ion. This study was conducted to determine if the ammonium ion could alter activated...... that the ammonium concentration would increase or by adding sodium. These studies showed that an increase in either sodium or ammonium would cause activated-sludge settling properties to deteriorate. When the monovalent-to-divalent cation ratio on a charge-equivalent basis was increased from 2.4 to 4.7 either...... by addition of sodium or ammonium, the interfacial settling velocity decreased, although the greatest drop was in the reactor containing ammonium. When addition of the nitrification inhibitor was stopped, rapid recovery of nitrification occurred but the settling properties improved more slowly. It seemed...

  5. Amines and ammonium compounds. CXCVIII. Reaction of ammonium salts containing a 2-alkynyl group with bromine and iodine

    Energy Technology Data Exchange (ETDEWEB)

    Gyul' nazaryan, A.K.; Khachatryan, N.G.; Saakyan, T.A.; Kinoyan, F.S.; Panosyan, G.A.; Babayan, A.T.

    1988-08-10

    The reactions of monoammonium, 1,4-and 1,5-bistertiaryammonium, and bisquaternary ammonium salts containing a 2-alkynyl group with bromine and iodine were studied. It was shown that these salts form molecular complexes with iodine and that addition of iodine at the triple bond does not occur. In reaction with bromine in all cases except 1,4-bistrimethylammonio-2-butyne dihalides one molecule of the halogen adds at the triple bond with the formation of salts containing the 2,3-dibromo-2-alkenyl group, which then form a 1:1 complex with bromine.

  6. Ober Phaseniibergange von Ammonium-Alkali-Jodiden und verwandten Halogeniden / Phase Transitions of Ammonium-alkali Iodides and Related Halides

    Science.gov (United States)

    Brauer, Peter

    1981-03-01

    The investigation of the order-disorder transitions of the ammonium-chlorides and -bromides, in which some of the NH4+ are replaced by Cs+, Rb+ or K+, is extended to the corresponding iodides using birefringence and differential thermal analysis. As the temperature range of the martensitic transition (Pm 3 m↔Fm 3 m) is now overlapping the temperature range of the orderdisorder transitions, the former must be included in the measurements. The results allowing an overlook are discussed using the work of Garland, Lushington, and Leung [5

  7. Shock Initiation and Equation of State of Ammonium Nitrate

    Science.gov (United States)

    Robbins, David; Sheffield, Steve; Dattelbaum, Dana; Chellappa, Raja; Velisavljevic, Nenad

    2013-06-01

    Ammonium nitrate (AN) is a widely used fertilizer and mining explosive commonly found in ammonium nitrate-fuel oil. Neat AN is a non-ideal explosive with measured detonation velocities approaching 4 km/s. Previously, we reported a thermodynamically-complete equation of state for AN based on its maximum density, and showed that near-full density AN did not initiate when subjected to shock input conditions up to 22 GPa. In this work, we extend these initial results, by presenting new Hugoniot data for intermediate density neat AN obtained from gas gun-driven plate impact experiments. AN at densities from 1.8 to 1.5 g/cm3 were impacted into LiF windows using a two-stage light gas gun. Dual VISARs were used to measure the interfacial particle velocity wave profile as a function of time following impact. The new Hugoniot data, in addition to updates to thermodynamic parameters derived from structural analysis and vibrational spectroscopy measurements in high pressure diamond anvil cell experiments, are used to refine the unreacted EOS for AN. Furthermore, shock initiation of neat AN was observed as the initial porosity increased (density decreased). Insights into the relationship(s) between initial density and shock initiation sensitivity are also presented, from evidence of shock initiation in the particle velocity profiles obtained for the lower density AN samples.

  8. Ammonium nitrate as an oxidizer in solid composite propellants

    Science.gov (United States)

    Manelis, G. B.; Lempert, D. B.

    2009-09-01

    Despite the fact that ammonium nitrate (AN) has the highest hydrogen content and fairly high oxygen balance (compared to other oxidizers), its extremely low formation enthalpy and relatively low density makes it one of the worst power oxidizers in solid composite propellants (SCP). Nevertheless, AN has certain advantages - the combustion of the compositions containing AN is virtually safe, its combustion products are ecologically clean, it is very accessible and cheap, and also very thermostable (far more stable than ammonium dinitramide (ADN)). Besides, its low density stops being a disadvantage if the propellant has to be used in deep space and therefore, must be carried there with other rocket carriers. The low cost of AN may also become a serious advantage in the AN application even in lower stages of multistage space launchers as well as in one-stage space launchers with low mass fraction of the propellant. The main specific features relevant to the creation of AN-based SCPs with the optimal energetic characteristics are discussed. The use of metals and their hydrides and proper fuel-binders as well as the recent successes in phase stabilization of AN are described.

  9. Optimized geometry, vibration (IR and Raman spectra and nonlinear optical activity of p-nitroanilinium perchlorate molecule: A theoretical study

    Directory of Open Access Journals (Sweden)

    Tamer Ömer

    2016-03-01

    Full Text Available The molecular modeling of p-nitroanilinium perchlorate molecule was carried out by using B3LYP and HSEH1PBE levels of density functional theory (DFT. The IR and Raman spectra were simulated and the assignments of vibrational modes were performed on the basis of relative contribution of various internal co-ordinates. NBO analysis was performed to demonstrate charge transfer, conjugative interactions and the formation of intramolecular hydrogen bonding interactions within PNAPC. Obtained large dipole moment values showed that PNAPC is a highly polarizable complex, and the charge transfer occurs within PNAPC. Hydrogen bonding and charge transfer interactions were also displayed by small HOMO-LUMO gap and molecular electrostatic potential (MEP surface. The strong evidences that the material can be used as an efficient nonlinear optical (NLO material of PNAPC were demonstrated by considerable polarizability and hyperpolarizability values obtained at DFT levels.

  10. Thermal, optical, mechanical and electrical properties of a novel NLO active L-phenylalanine L-phenylalaninium perchlorate single crystals

    International Nuclear Information System (INIS)

    Single crystals of L-phenylalanine L-phenylalaninium perchlorate (LPAPCl), a semiorganic nonlinear (NLO) material have been successfully grown up to a size of 14 mmx5 mmx3 mm. The lattice parameters of the grown crystals are determined by single crystal XRD. The UV-Vis-NIR spectrum of LPAPCl show less optical absorption in the entire visible region. Nonlinear optical study reveals that the SHG efficiency of LPAPCl is nearly 1.4 times that of KDP. The laser damage density is found to be 7.4 GW/cm2. The crystals are subjected to microhardness studies and the variation of the microhardness with the applied load is studied. The response of dielectric constant in the frequency region of 50 Hz to 5 MHz has been investigated. AC and DC conductivity and photoconductivity experiments are also carried out and the results are discussed.

  11. Synthesis of N-(3-(Dimethylamino)-2-(4-Ethoxyphenyl) Alllidene)-N-Methylmethanaminium Perchlorate by Willgerodt-Kindler Reaction

    Institute of Scientific and Technical Information of China (English)

    REN Wei-min; WANG Xing-yong; YANG Hai-tao; SHI Gui-zhen; LI Feng

    2006-01-01

    Liquid crystals containing phenylpyrimidine units are the fascination condensed state of soft matter with unique electrical, optical and mechanical properties. In this paper, a novel and efficient route was reported for the synthesis of N-(3-(dimethylamino)-2-(4-ethoxyphenyl)allylidene)-N-methylmethanaminium perchlorate by the WillgerodtKindler reaction, which can be further applied to prepare liquid crystals containing phenylpyrimidine units. The product was confirmed by 1HNMR, MS, FT-IR and elemental analysis. The experimental conditions of the Willgerodt-Kindler reaction were also studied and the results show that the yield ofp-ethoxyphenyl-acetic acid increased remarkably with a reaction time up to 60 min, then decreased due to carbonization. On the other hand, the yield was also influenced by microwave power. It increased from 20.6 % to 78.8 % with a rise in the microwave power from 250 W to 450 W, but the product was carbonized at 640 W.

  12. Optimized pyroelectric properties of 0-3 composites of PZT particles in polyurethane doped with lithium perchlorate.

    Science.gov (United States)

    Ploss, Bernd; Krause, Markus

    2007-12-01

    A substantial improvement in the performance of pyroelectric 0-3 composites of ceramic particles in a polymer matrix has been achieved by doping the polymer matrix material. Readily prepared and polarized films with various volume fractions of lead zirconate-titanate (PZT) particles in polyurethane have been doped in a solution of lithium perchlorate in acetone to increase the conductivity. With an appropriate conductivity, the dielectric permittivities of the ceramic particles and the polymer matrix become matched, resulting in an improvement of the pyroelectric coefficient from about 6 microC/(m(2)K) to about 50 microC/(m(2)K). The experimental results are explained by theoretical predictions. PMID:18276541

  13. Concentration of zinc ions in perchlorate medium by a menbrane-gel using an acid extractant (DEHPA

    Directory of Open Access Journals (Sweden)

    Belhadji L.

    2013-07-01

    Full Text Available Recent decades, it is an awareness of the importance of ecological balance in the environment, balances threatened by industrial pollution. A new spirit presides we seek to minimize pollution of receiving waters. The present work is to study the liquid-gel-extraction of zinc ions in perchlorate medium by an acid extractant: the di (ethyl-2 hexyl phosphorique acid, or DEHPA. Two types of polymers were used as supports of solvent extraction: a polybutadiene rubber cross-linked respectively with 0.1% dicumyl peroxide and 0.4% dicumyl peroxide, vulcanized at 160°C, one is most cross-linked than the other. The liquid-gel extraction is based on the principles of the liquid-liquid extraction.

  14. Effects of Calcium Lignosulfonate and Silicic Acid on Ammonium Nitrate Degradation

    Directory of Open Access Journals (Sweden)

    Ahmet Ozan Gezerman

    2014-01-01

    Full Text Available Ammonium nitrate salts are the most commonly used nitrogenous fertilizers in industry. However, storage of ammonium nitrate is problematic, since its initial properties can decline because of environmental factors, leading to large economic losses. In this study, in order to prevent the caking and degradation of ammonium nitrate, an alternative composition with additional calcium lignosulfonate and silicic acid was studied. The resulting fertilizer was analyzed by screening analysis, ion chromatography, and electron microscopy methods.

  15. Influence of different ammonium, lactate and glutamine concentrations on CCO cell growth

    OpenAIRE

    Slivac, Igor; Blajić, Višnja; Radošević, Kristina; Kniewald, Zlatko; Gaurina Srček, Višnja

    2010-01-01

    In this study the effects of ammonium and lactate on a culture of channel catfish ovary (CCO) cells were examined. We also made investigation on the influence of glutamine, since our previous research revealed that this amino acid stimulated CCO cell growth more than glucose in a concentration-dependent manner. The effect of ammonium in cell culture included the considerable decrease in cell growth rate with eventual growth arrest as well as the retardation of glucose consumption. At ammonium...

  16. Ammonium removal from municipal wastewater with application of ion exchange and partial nitritation/Anammox process

    OpenAIRE

    Malovanyy, Andriy

    2014-01-01

    Nitrogen removal from municipal wastewater with application of Anammox process offers cost reduction, especially if it is combined with maximal use of organic content of wastewater for biogas production. In this study a new technology is proposed, which is based on ammonium concentration from municipal wastewater by ion exchange followed by biological removal of ammonium from the concentrated stream by partial nitritation/Anammox process. In experiments on ammonium concentration four the most...

  17. Influence of Ammonium Salts and Cane Molasses on Growth of Alcaligenes eutrophus and Production of Polyhydroxybutyrate

    OpenAIRE

    Beaulieu, M.; Beaulieu, Y.; Melinard, J.; Pandian, S.; GOULET, J.

    1995-01-01

    The production of polyhydroxybutyrate (PHB) by Alcaligenes eutrophus DSM 545 was studied in a synthetic medium with 3% glucose at pH 7.0 supplemented with several ammonium substrates and cane molasses. Growth was measured by dry cell weight, and the PHB content was measured by gas chromatography. The effects of ammonium sources such as sulfate, nitrate, phosphate, and chloride salts and those of different ammonium sulfate concentrations were evaluated. The best growth and PHB production were ...

  18. Studies on Biquaternary Ammonium Salt Algaecide for Removing Red Tide Algae

    Institute of Scientific and Technical Information of China (English)

    刘洁生; 张珩; 杨维东; 高洁; 柯琼

    2004-01-01

    The paper deals with the removal and control of red tide algae, Phaeoecystis globosa and Alexandrium tamarense by biquaternary ammonium salt algaecide. The results show that the efficient concentration of biquaternary ammonium salt to control the two algaes in 96 h is 0.8 mg · L-1 and 0.4 mg · L-1, respectively. It is found that biquaternary ammonium salt has high efficiency and longer duration of action in the removal and control of algae.Biquaternary ammonium salt might be an excellent algaecide to control HAB.

  19. Highly efficient hydrogen storage system based on ammonium bicarbonate/formate redox equilibrium over palladium nanocatalysts.

    Science.gov (United States)

    Su, Ji; Yang, Lisha; Lu, Mi; Lin, Hongfei

    2015-03-01

    A highly efficient, reversible hydrogen storage-evolution process has been developed based on the ammonium bicarbonate/formate redox equilibrium over the same carbon-supported palladium nanocatalyst. This heterogeneously catalyzed hydrogen storage system is comparable to the counterpart homogeneous systems and has shown fast reaction kinetics of both the hydrogenation of ammonium bicarbonate and the dehydrogenation of ammonium formate under mild operating conditions. By adjusting temperature and pressure, the extent of hydrogen storage and evolution can be well controlled in the same catalytic system. Moreover, the hydrogen storage system based on aqueous-phase ammonium formate is advantageous owing to its high volumetric energy density.

  20. Diastereoisomeric β-ethyl aspartate-cobalt(III) complexes: Λ(+)578- and Δ(-)578-bis(ethane-1,2-diamine)[β-ethyl (S)-aspartato]cobalt(III) bis(perchlorate) monohydrate.

    Science.gov (United States)

    Hammershøi, Anders; Schau-Magnussen, Magnus; Bendix, Jesper; Mølgaard, Anne

    2010-11-01

    The structures of the diastereoisomers Λ(+)(578)-, (I), and Δ(-)(578)-bis(ethane-1,2-diamine)[β-ethyl (S)-aspartato-κ(2)N,O(1)]cobalt(III) bis(perchlorate) monohydrate, (II), both [Co(C(6)H(10)N(2)O(4))(C(2)H(8)N(2))(2)](ClO(4))(2)·H(2)O, are compared. In both structures, the ester group of the amino acid side chain is engaged only in intramolecular hydrogen bonding to coordinated amine groups. This interaction is stronger in (I) and correlates with previously observed diastereoisomeric equilibrium ratios for related metal complex systems in aqueous media. The two perchlorate anions of (II) are located on twofold axes. Both perchlorates in (I) and one of the perchlorates in (II) are affected by disorder. Both structures exhibit extensive three-dimensional hydrogen-bonding networks.

  1. The perchlorate discharge test with {sup 123}I for the diagnosis of the Pendred syndrome in children; Der Depletionstest mit {sup 123}Iod zur Diagnose des Pendred-Syndroms bei Kindern

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, K.; Fischer, S. [Klinik und Poliklinik fuer Nuklearmedizin, Klinikum der Ludwig-Maximilians-Univ. Muenchen (Germany)

    2009-03-15

    The method for the diagnosis of the Pendred Syndrome in children by the Perchlorate discharge test using {sup 123}I is described. The older child, who has the Pendred Syndrome and the obligatory hearing deficit, frequently has neither a goitre nor hypothyroidism, but other investigations (bone growth, scars and function tests) can also show changes. However a more certain diagnosis of this disorder in children is possible by the perchlorate discharge test using {sup 123}I. (orig.)

  2. 生物修复高氯酸盐污染的研究进展%Research advance in bioremediation technology of perchlorate contamination

    Institute of Scientific and Technical Information of China (English)

    高海硕; 陈桂葵; 黎华寿

    2012-01-01

    生物修复技术是目前高氯酸盐污染环境整治的最具潜力的修复技术之一,具有成本低、无二次污染的特点,是国内外一个新的研究热点,亦是仅见的污染控制及修复的环境友好技术.介绍了环境中高氯酸盐污染的来源与分布,阐述了生物修复(主要包括植物修复和微生物修复)的特点及作用机制,认识到2种类型修复技术各有其优劣势;重点综述了生物修复高氯酸盐污染的国内外研究现状,得出植物根际降解对植物修复高氯酸盐起着十分重要作用,而微生物修复是目前最有希望获得大规模应用的高氯酸盐污染修复技术;最后提出了植物微生物联合强化修复高氯酸盐污染的技术将更具应用前景.%Bioremediation is the most potential technologies in perchlorate contamination remediation. As the only environmentally friendly remediation technologies so far, bioremediation technology had the advantage of low cost and no secondary pollution,it become a new research hotspot at home and abroad. This paper introduced the source and distribution of perchlorate contamination,described the characteristics and mechanism of bioremediation technology (mainly included phytoremediation and microbial remediation) in perchlorate contamination remediation; the advantages and disadvantages of these two bioremediation techniques was summarized and compared. The research status of perchlorate contamination bioremediation was reviewed. It was found that plant rhizosphere degradation played an important role in phytoremediation;microbial remediation was the most hopeful technology for large-scale application in perchlorate pollution remediation. The phyto-microbial strengthen remediation technology was put forward; it would had more application prospects in perchlorate contamination remeditation.

  3. Ammonium sulphate on maize crops under no tillage

    Directory of Open Access Journals (Sweden)

    Maria Anita Gonçalves da Silva

    2012-01-01

    Full Text Available The objectives of this work were to evaluate the management of N and S (as ammonium sulphate fertilization under no-tillage system on the components of maize productivity and on N and S accumulation in the crop, as well as to evaluate the minimum value of the Nitrogen Sufficiency Index (NSI 0.95 as an indicator for side dressing requirements. The experiment had a completely randomized block design with six treatments and four replications carried out in Red Latosol dystrophic soil (Hapludox, in Campo Mourão, Paraná State, where the following treatments in summer growth maize were applied: T1- 120 kg ha-1 N in seeding; T2- 120 kg ha-1 N in side dressing; T3- 40 kg ha-1 N in seeding and 80 kg ha-1 N in side dressing; T4- 30 kg ha-1 N in seeding and 90 kg ha-1 N in side dressing, monitored by a chlorophyll meter using the Nitrogen Sufficiency Index (NSI; T5- 120 kg ha-1 N anticipated in wheat seeding; T6- without nitrogen fertilization. NSI was determined by the relationship between the leaf chlorophyll index (ICF average of T4 plants and that one in the plot fertilized with 120 kg ha-1 N at the maize seed sowing (T1. During two years, ammonium sulphate was applied to the maize crop after wheat under no tillage system. In the first year, with adequate rainfall, the maize yield was similar to the one in which the complete ammonium sulphate dose application was done in maize seeding and side dressing. The anticipated fertilization to wheat seed sowing resulted in maize yield without difference from the parceled form. In the second year, with irregular rainfall, all treatments with N were similar and they increased maize yield compared to that without N fertilization. NSI of 0.95 was not efficient to evaluate maize N requirements in side dressing, and resulted in lower maize yield. N was accumulated mainly in the grains unlike S that accumulated in the plant shoots; both were highly correlated to maize productivity.

  4. Studies on extraction of beryllium from thiocyanate solutions by quaternary ammonium halides.

    Science.gov (United States)

    El-Yamani, I S; El-Messieh, E N

    A 0.4M tricaprylmethylammonium chloride solution in n-hexane was used for the quantitative extraction of beryllium from hydrochloric acid (pH 3) and 5M potassium thiocyanate. Beryllium was stripped from the organic phase with 1M sodium hydroxide, then determined volumetrically with bismuthyl perchlorate and bromocresol green indicator. Beryllium was extracted in presence of a large number of elements which are usually associated with it in beryl and in fission products of nuclear fuel.

  5. Single stage biological nitrogen removal by nitritation and anaerobic ammonium oxidation in biofilm systems.

    Science.gov (United States)

    Helmer, C; Tromm, C; Hippen, A; Rosenwinkel, K H; Seyfried, C F; Kunst, S

    2001-01-01

    In full scale wastewater treatment plants with at times considerable deficits in the nitrogen balances, it could hitherto not be sufficiently explained which reactions are the cause of the nitrogen losses and which micro-organisms participate in the process. The single stage conversion of ammonium into gaseous end-products--which is henceforth referred to as deammonification--occurs particularly frequently in biofilm systems. In the meantime, one has succeeded to establish the deammonification processes in a continuous flow moving-bed pilot plant. In batch tests with the biofilm covered carriers, it was possible for the first time to examine the nitrogen conversion at the intact biofilm. Depending on the dissolved oxygen (DO) concentration, two autotrophic nitrogen converting reactions in the biofilm could be proven: one nitritation process under aerobic conditions and one anaerobic ammonium oxidation. With the anaerobic ammonium oxidation, ammonium as electron donor was converted with nitrite as electron acceptor. The end-product of this reaction was N2. Ammonium and nitrite did react in a stoichiometrical ratio of 1:1.37, a ratio which has in the very same dimension been described for the ANAMMOX-process (1:1.31 +/- 0.06). Via the oxygen concentration in the surrounding medium, it was possible to control the ratio of nitritation and anaerobic ammonium oxidation in the nitrogen conversion of the biofilm. Both processes were evenly balanced at a DO concentration of 0.7 mg/l, so that it was possible to achieve a direct, almost complete elimination of ammonium without addition of nitrite. One part of the provided ammonium did participate in the nitritation, the other in the anaerobic ammonium oxidation. Through the aerobic ammonium oxidation into nitrite within the outer oxygen supplied layers of the biofilm, the reaction partner was produced for the anaerobic ammonium oxidation within the inner layers of the biofilm. PMID:11379106

  6. Effects of various iron hydroxides on burning rate of ammonium phercholate/hydroxyl-terminated polybutadiene composite propellants. AP/HTPB kei suishin'yaku no nensho sokudo ni oyobosu kakushu suisanka dai 2 tetsu no koka

    Energy Technology Data Exchange (ETDEWEB)

    Koga, M.; Suzuki, M.; Hagihara, Y. (The National Defense Academy, Kanagawa (Japan))

    1992-12-25

    Researches are being moved forward on combustion catalysts for ammonium perchlorate/hydroxyl-terminated polybutadiene (AP/HTPB) composite propellants. The previous paper has reported that various iron oxide catalysts with the larger the specific surface area exhibit larger effect of increasing combustion rates. This paper investigates subsequently ferric hydroxides with still smaller specific surface area than iron oxides for their effects of increasing combustion rates when used as a catalyst. As a result, it was found that ferric hydroxide with the larger the specific surface area shows larger effects of increasing combustion rates as in iron oxides. Compared with iron oxide with the largest specific surface area of 22.8 m[sup 2]/g among the iron oxides used in the previous report, ferric hydroxide used in this experiment with more than four times as much specific surface area of 87 to 104 m[sup 2]/g showed larger effects. It was thought that specific surface areas govern the catalytic effect and accelerate thermal decomposition in solid phase. 6 refs., 4 figs., 5 tabs.

  7. Studies on a Cationically Modified Quaternary Ammonium Salt of Lignin

    Institute of Scientific and Technical Information of China (English)

    YANG Ai-li; JIANG Wen-ju

    2007-01-01

    A new quaternary ammonium salt monomer was synthesized and a quaternary amination of lignin( noted as QL),with the monomer was carried out by grafting copolymerization. The products were characterized by Fourier Transform Infrared spectroscopy(FTIR). The experimental results indicate that the yield of the monomer was 99.06%, and the conversion of the monomer and the grafting yield of QL were 93.69% and 185.78%, respectively. The feasibility of QL as the fiocculant to be applied in color removal of five artificial dyes, eriochrome black T( dye A), gongo red( dye B), direct fast black G (dye C), cuprofix blue green B (dye D), and acid black ATT (dye E) was examined.Results show that QL exhibits the favorable flocculation performance and high stability.

  8. Crystal structure of tris-(hydroxyl-ammonium) orthophosphate.

    Science.gov (United States)

    Leinemann, Malte; Jess, Inke; Boeckmann, Jan; Näther, Christian

    2015-11-01

    The crystal structure of the title salt, ([H3NOH](+))3·[PO4](3-), consists of discrete hydroxyl-ammonium cations and ortho-phos-phate anions. The atoms of the cation occupy general positions, whereas the anion is located on a threefold rotation axis that runs through the phospho-rus atom and one of the phosphate O atoms. In the crystal structure, cations and anions are linked by inter-molecular O-H⋯O and N-H⋯O hydrogen bonds into a three-dimensional network. Altogether, one very strong O-H⋯O, two N-H⋯O hydrogen bonds of medium strength and two weaker bifurcated N-H⋯O inter-actions are observed. PMID:26594525

  9. Antibacterial effect of composite resins containing quaternary ammonium polyethyleneimine nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Yudovin-Farber, Ira [Hebrew University of Jerusalem, Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Faculty of Medicine (Israel); Beyth, Nurit; Weiss, Ervin I. [Hebrew University of Jerusalem, Department of Prosthodontics, Faculty of Dentistry (Israel); Domb, Abraham J., E-mail: avid@ekmd.huji.ac.i [Hebrew University of Jerusalem, Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Faculty of Medicine (Israel)

    2010-02-15

    Quaternary ammonium polyethyleneimine (QA-PEI)-based nanoparticles were synthesized by crosslinking with dibromopentane followed by N-alkylation with various alkyl halides and further N-methylation with methyl iodide. Insoluble pyridinium-type particles were prepared by suspension polymerization of 4-vinyl pyridine followed by N-alkylation with alkyl halides. Polyamine-based nanoparticles embedded in restorative composite resin at 1% w/w were tested for antibacterial activity against Streptococcus mutans using direct contact test. Activity analysis revealed that the alkyl chain length of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl-alkylated QA-PEI embedded in restorative composite resin at 1% w/w that totally inhibited S. mutans growth in 3-month-aged samples. This data indicates that restorative composite resin with antibacterial properties can be produced by the incorporation of QA-PEI nanoparticles.

  10. Polishing of quartz by rapid etching in ammonium bifluoride.

    Science.gov (United States)

    Vallin, Orjan; Danielsson, Rolf; Lindberg, Ulf; Thornell, Greger

    2007-07-01

    The etch rate and surface roughness of polished and lapped AT-cut quartz subjected to hot (90, 110, and 130 degrees C), concentrated (50, 65, 80 wt %) ammonium bi-fluoride have been investigated. Having used principal component analysis to verify experimental solidity and analyze data, we claim with confidence that this parameter space does not, as elsewhere stated, allow for a polishing effect or even a preserving setting. Etch rates were found to correlate well, and possibly logarithmically, with temperature except for the hottest etching applied to lapped material. Roughness as a function of temperature and concentration behaved well for the lapped material, but lacked systematic variation in the case of the polished material. At the lowest temperature, concentration had no effect on etch rate or roughness. Future efforts are targeted at temperatures and concentrations closer to the solubility limit.

  11. Ammonium derivatives of chromenones and quinolinones as lead antimicrobial agents

    Indian Academy of Sciences (India)

    Shilpi Gupta; Seema Singh; Abha Kathuria; Manish Kumar; Sweta Sharma; Ram Kumar; Virinder S Parmar; Bharat Singh; Anjali Gupta; Erik Van Der Eycken; Gainda L Sharma; Sunil K Sharma

    2012-03-01

    A series of novel ammonium derivatives were synthesized and examined for their antimicrobial efficacy. Comparison of antimicrobial spectrum revealed that compounds 9, 11, 16 and 23 had strong potential against pathogens in vitro. Cytotoxicity results showed compound 9 to be least toxic, it is non-toxic to A549 and U87 cells in MTT assay and exhibits marginal toxicity (15-20%) to human erythrocytes at a concentration of 1000 g/ml as compared to 100% lysis of cells by 31.25 g/ml of the standard drug amphotericin B. This compound has MIC values in the range of 1.95-31.25 g/disc in DDA against different pathogens and may considered to be an important lead antimicrobial molecule for further exploration.

  12. A facile synthesis of ω-aminoalkyl ammonium hydrogen phosphates

    Institute of Scientific and Technical Information of China (English)

    Wei Bo Kong; Xiao Yong Zhou; Yang Yang; Xing Yi Xie

    2012-01-01

    A series of ω-aminoalkyl ammonium hydrogen phosphates were synthesized through a simple and efficient three-step method.The starting materials,ω-aminoalkyl alcohols (AC-n,with carbon number n =3,4,5,6),were amino-protected with 9-fluorenylmethyl chloroformate (Fmoc-Cl),followed by phosphorylation with POCl3 and deprotection in piperidine/DMF The structures of each intermediate and final product were confirmed by 1H NMR,FTIR and mass spectrum.The yield of each step was about 77-92%,with a total yield higher than 56%.This new method was superior in low-cost raw materials,mild reaction temperatures (0-25 ℃) and easy purification methods.

  13. Hibiscus sabdariffa Affects Ammonium Chloride-Induced Hyperammonemic Rats

    Directory of Open Access Journals (Sweden)

    M. Mohamed Essa

    2007-01-01

    Full Text Available Hibiscus sabdariffa (HS is an edible medicinal plant, indigenous to India, China and Thailand and is used in Ayurveda and traditional medicine. Alcoholic extract of HS leaves (HSEt was studied for its anti-hyperammonemic and antioxidant effects in brain tissues of ammonium chloride-induced hyperammonemic rats. Oral administration of HSEt (250 mg kg−1 body weight significantly normalizes the levels of ammonia, urea, uric acid, creatinine and non-protein nitrogen in the blood. HSEt significantly reduced brain levels of lipid peroxidation products such as thiobarbituric acid and reactive substances (TBARS and hydroperoxides (HP. However, the administered extract significantly increased the levels of antioxidants such as catalase (CAT, superoxide dismutase (SOD, glutathione peroxidase (GPx and reduced glutathione (GSH in brain tissues of hyperammonemic rats. This investigation demonstrates significant anti-hyperammonemic and antioxidant activity of HS.

  14. Integrated Data Collection Analysis (IDCA) Program — Ammonium Nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Sandstrom, Mary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Geoffrey W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Daniel N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pollard, Colin J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Warner, Kirstin F. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Sorensen, Daniel N. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Remmers, Daniel L. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Phillips, Jason J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Shelley, Timothy J. [Bureau of Alcohol, Tobacco and Firearms, Redstone Arsenal, AL (United States); Reyes, Jose A. [Applied Research Associates, Tyndall AFB, FL (United States); Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-05-17

    The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of ammonium nitrate (AN). AN was tested, in most cases, as both received from manufacturer and dried/sieved. The participants found the AN to be: 1) insensitive in Type 12A impact testing (although with a wide range of values), 2) completely insensitive in BAM friction testing, 3) less sensitive than the RDX standard in ABL friction testing, 4) less sensitive than RDX in ABL ESD testing, and 5) less sensitive than RDX and PETN in DSC thermal analyses.

  15. Review of Options for Ammonia/Ammonium Management

    Energy Technology Data Exchange (ETDEWEB)

    Nash, C. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-05-06

    This report is a review of literature supporting practical ammonia/ammonium destruction processes. Melter research supporting Hanford Low Activity Waste (LAW) glass production has shown that significant amounts of ammonia will be in the melter offgas condensate. Further work with secondary waste forms indicates the potential need to remove the ammonia, perhaps by an oxidative process. This review finds likely practical chemical methods to oxidize ammonia in aqueous solution at moderate temperatures and atmospheric pressure, using easily obtained reagents. Leading candidates include nitrite oxidation to produce nitrogen gas, various peroxide oxidative processes, and air stripping. This work reviews many other processes and provides reasoning to not consider those processes further for this application.

  16. Cold Case: Radar investigation of ammonium sulfate cryovolcanism on Titan

    Science.gov (United States)

    Thomann, C.; Hayes, A. G.; Hofgartner, J.; Lunine, J. I.; Le Gall, A.

    2012-12-01

    The detection of a large tidal k2 value from Cassini [1] constitutes very strong evi-dence for a subcrustal ocean, most plausibly dominated by water. However, the secondary constituents are not known. One interesting possibility that has received scant attention in analysis of surface data sets is that the ocean contain aqueous ammonium sulfates, which erupted on the surface in the past to create vast, smooth plains [2]. We adopt the hypothesis that the undifferentiated plains—the "bland-lands" in the mid-latitudes of Titan—are these deposits, and test it using radiometry with SAR data. Lopez et al (this conference) investigate the global distribution and possible origin of this type of unit. We extracted SAR and radiometry-during-SAR data sets from the PDS, and pro-duced maps of brightness temperatures. The SAR imagery was used to identify locations where crossovers exist -some of which are in the undifferentiated plains--and hence where brightness temperatures at different incidence angles are available. We derived emissivities from the data using a simple radiometric model [3] to ac-count for the brightness temperature differences as a function of surface roughness, volume scattering and emissivity. We test the hypothesis by assessing whether the derived emissivities and volume scattering in the bland-lands are consistent with the model cryoclastic ash of ice and ammonium sulfate proposed in [2], distinct from that in other terrains. [1] L. Iess, R.A. Jacobson, M. Ducci, D.J. Stevenson, J.I. Lunine, J.W. Armstrong, S.W. Asmar, P. Racioppa, N.J. Rappaport, P. Tortora, Science, 337, 457 (2012). [2] A.D. Fortes, P.M. Grinrod, S.K. Trickett, L. Vocadlo. Icarus, 188, 139 (2007). [3] T.L. White and J.R. Cogdell. The Moon, 6, 235 (1973).

  17. Oxidation of alginate and pectate biopolymers by cerium(IV) in perchloric and sulfuric acid solutions: A comparative kinetic and mechanistic study.

    Science.gov (United States)

    Fawzy, Ahmed

    2016-03-15

    The kinetics of oxidation of alginate (Alg) and pectate (Pec) carbohydrate biopolymers was studied by spectrophotometry in aqueous perchloric and sulfuric acid solutions at fixed ionic strengths and temperature. In both acids, the reactions showed a first order dependence on [Ce(IV)], whereas the orders with respect to biopolymer concentrations are less than unity. In perchloric acid, the reactions exhibited less than unit orders with respect to [H(+)] whereas those proceeded in sulfuric acid showed negative fractional-first order dependences on [H(+)]. The effect of ionic strength and dielectric constant was studied. Probable mechanistic schemes for oxidation reactions were proposed. In both acids, the final oxidation products were characterized as mono-keto derivatives of both biopolymers. The activation parameters with respect to the slow step of the mechanisms were computed and discussed. The rate laws were derived and the reaction constants involved in the different steps of the mechanisms were calculated.

  18. Control of Sulfidogenesis Through Bio-oxidation of H2S Coupled to (per)chlorate Reduction

    Energy Technology Data Exchange (ETDEWEB)

    Gregoire, Patrick [Univ. of California, Berkeley, CA (United States); Engelbrektson, Anna [Univ. of California, Berkeley, CA (United States); Hubbard, Christopher G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Metlagel, Zoltan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Csencsits, Roseann [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Auer, Manfred [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Conrad, Mark E. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Thieme, Jurgen [Brookhaven National Lab. (BNL), Upton, NY (United States); Northrup, Paul [Brookhaven National Lab. (BNL), Upton, NY (United States); Coates, John D. [Univ. of California, Berkeley, CA (United States)

    2014-04-04

    Here, we investigate H2S attenuation by dissimilatory perchlorate-reducing bacteria (DPRB). All DPRB tested oxidized H2S coupled to (per)chlorate reduction without sustaining growth. H2S was preferentially utilized over organic electron donors resulting in an enriched (34S)-elemental sulfur product. Electron microscopy revealed elemental sulfur production in the cytoplasm and on the cell surface of the DPRB Azospira suillum. We also propose a novel hybrid enzymatic-abiotic mechanism for H2S oxidation similar to that recently proposed for nitrate-dependent Fe(II) oxidation. The results of this study have implications for the control of biosouring and biocorrosion in a range of industrial environments.

  19. Clinoptilolite-based mixed matrix membranes for the selective recovery of potassium and ammonium

    NARCIS (Netherlands)

    Casadella, A.; Kuntke, P.; Schaetzle, O.; Loos, K.

    2016-01-01

    . A clinoptilolite-based mixed matrix membrane (MMM) was developed and studied for the selective recovery of ammonium and potassium. Adsorption of sodium (Na+), potassium (K+) and ammonium (NH4+) was investigated with single salt and equimolar salt solution under static and dynamic conditions. Furth

  20. 75 FR 56489 - Separation Distances of Ammonium Nitrate and Blasting Agents From Explosives or Blasting Agents...

    Science.gov (United States)

    2010-09-16

    ... definition of ammonium nitrate fertilizer issued by the Fertilizer Institute'' in its ``Definition and Test Procedures for Ammonium Nitrate Fertilizer.'' The Fertilizer Institute (TFI) ] is a voluntary, non-profit trade association of the fertilizer industry that currently has more than 175 members. See...

  1. 76 FR 23569 - Termination of the Suspension Agreement on Solid Fertilizer Grade Ammonium Nitrate From the...

    Science.gov (United States)

    2011-04-27

    ... Antidumping Duty Investigation: Solid Fertilizer Grade Ammonium Nitrate from the Russian Federation, 64 FR... Less Than Fair Value: Solid Fertilizer Grade Ammonium Nitrate from the Russian Federation, 65 FR 1139... International Trade Administration Termination of the Suspension Agreement on Solid Fertilizer Grade...

  2. Photo-Fenton-like degradation of azo dye methyl orange using synthetic ammonium and hydronium jarosite

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhihui [Department of Chemistry, College of Science, Nanjing Agricultural University, Nanjing 210095 (China); Liang, Jianru [Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Zhou, Lixiang, E-mail: lxzhou@njau.edu.cn [Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China)

    2013-01-05

    Highlights: Black-Right-Pointing-Pointer Hydronium and ammonium jarosite could catalyze the oxidation of methyl orange in photo-Fenton-like process. Black-Right-Pointing-Pointer The oxidation process is essentially heterogeneous, not homogeneous. Black-Right-Pointing-Pointer Hydronium jarosite has stronger reactivity than ammonium jarosite. - Abstract: Ammonium and hydronium jarosite were prepared by hydrothermal method with urea as the homogeneous precipitant. X-ray diffraction, field-emission scanning electron microscope, X-ray photoelectron spectrum, UV-vis spectra and fourier transform infrared spectrum were used to characterize the resulting products. The photodegradation efficiency of the prepared ammonium and hydronium jarosite was studied in a photo-Fenton-like process using methyl orange (MO) as target pollutant. The photocatalytic degradation of MO over synthetic ammonium and hydronium jarosite under various conditions, such as catalysts loading, H{sub 2}O{sub 2} concentration and initial pH, has been investigated. Results show that ammonium and hydronium jarosite have satisfactory photocatalysis effect in degradation of MO azo dye, and that the reactivity of hydronium jarosite toward the mineralization of MO was higher than that of ammonium jarosite. The novel ammonium and hydronium jarosite catalysts would be important for industrial applications due to their high photoactivity, little iron leaching and low cost.

  3. Ammonium across a Selective Polymer Inclusion Membrane : Characterization, Transport, and Selectivity

    NARCIS (Netherlands)

    Casadella, Anna; Schaetzle, Olivier; Loos, Katja

    2016-01-01

    The recovery of ammonium from urine requires distinguishing and excluding sodium and potassium. A polymer inclusion membrane selective for ammonium is developed using an ionophore based on pyrazole substituted benzene. The interactions of the components are studied, as well as their effect on transp

  4. Temperature effects in the absorption spectra and exciton luminescence in ammonium halides

    International Nuclear Information System (INIS)

    Warm-up behavior of the first maximum exciton absorption bands in ammonium halides is explored. Under phase transition occurs offset of bands, bound both with changing a parameter of lattice, and efficient mass of exciton. Warm-up dependency of quantum leaving a luminescence of self-trapped excitons in ammonium halides is measured. (author)

  5. On the influence of thiamine and ammonium ions on alcoholic fermentation

    NARCIS (Netherlands)

    Maesen, Th.J.M.

    1953-01-01

    1. 1. In a glucose-sodium acetate medium of pH 5.6 the fermentation rate of bakers' yeast remains constant at a low level during several hours, while in the presence of ammonium sulphate it gradually increases. The rise is steeper in the presence of thiamine. 2. 2. After the ammonium ions have been

  6. Effects of Ammonium and Nitrite on Growth and Competitive Fitness of Cultivated Methanotrophic Bacteria▿

    OpenAIRE

    Nyerges, Györgyi; Han, Suk-Kyun; Stein, Lisa Y.

    2010-01-01

    The effects of nitrite and ammonium on cultivated methanotrophic bacteria were investigated. Methylomicrobium album ATCC 33003 outcompeted Methylocystis sp. strain ATCC 49242 in cultures with high nitrite levels, whereas cultures with high ammonium levels allowed Methylocystis sp. to compete more easily. M. album pure cultures and cocultures consumed nitrite and produced nitrous oxide, suggesting a connection between denitrification and nitrite tolerance.

  7. Ammonium-oxidizing bacteria facilitate aerobic degradation of sulfanilic acid in activated sludge.

    Science.gov (United States)

    Chen, Gang; Ginige, Maneesha P; Kaksonen, Anna H; Cheng, Ka Yu

    2014-01-01

    Sulfanilic acid (SA) is a toxic sulfonated aromatic amine commonly found in anaerobically treated azo dye contaminated effluents. Aerobic acclimatization of SA-degrading mixed microbial culture could lead to co-enrichment of ammonium-oxidizing bacteria (AOB) because of the concomitant release of ammonium from SA oxidation. To what extent the co-enriched AOB would affect SA oxidation at various ammonium concentrations was unclear. Here, a series of batch kinetic experiments were conducted to evaluate the effect of AOB on aerobic SA degradation in an acclimatized activated sludge culture capable of oxidizing SA and ammonium simultaneously. To account for the effect of AOB on SA degradation, allylthiourea was used to inhibit AOB activity in the culture. The results indicated that specific SA degradation rate of the mixed culture was negatively correlated with the initial ammonium concentration (0-93 mM, R²= 0.99). The presence of AOB accelerated SA degradation by reducing the inhibitory effect of ammonium (≥ 10 mM). The Haldane substrate inhibition model was used to correlate substrate concentration (SA and ammonium) and oxygen uptake rate. This study revealed, for the first time, that AOB could facilitate SA degradation at high concentration of ammonium (≥ 10 mM) in an enriched activated sludge culture.

  8. Suppression of interference in the AAS determination of chromium by use of ammonium bifluoride.

    Science.gov (United States)

    Purushottam, A; Naidu, P P; Lal, S S

    1973-07-01

    Addition of 1% of ammonium bifluoride successfully suppresses interference by diverse ions in the atomic-absorption determination of chromium(VI). If the sample solutions also contain chromium(III) addition of 1% of ammonium bifluoride and 0.2% of sodium sulphate is recommended for the suppression.

  9. Irritant contact dermatitis due to ammonium bifluoride in two infant twins.

    Science.gov (United States)

    Toledo, Fernando; Silvestre, Juan Francisco; Cuesta, Laura; Bañuls, José

    2013-01-01

    Ammonium bifluoride is one of the most corrosive acids that may produce severe chemical burns when in contact with skin. This hazardous chemical is widely used in household products. We report two pediatric cases of irritant contact dermatitis after exposure to a rust remover, which contained ammonium bifluoride.

  10. Effect of quaternary ammonium salts on flotation behavior of aluminosilicate minerals

    Institute of Scientific and Technical Information of China (English)

    ZHAO Sheng-gui; ZHONG Hong; LIU Guang-yi

    2007-01-01

    The electrokinetic properties and flotation of diaspore, kaolinite, pyrophyllite and illite with quaternary ammonium salts collectors were studied. The results of flotation tests show that the collecting ability of quaternary ammonium salts for the four minerals is in the order(from strong to weak) of octadecyl dimethyl benzyl ammonium chloride(ODBA), cetyl trimethyl ammonium bromide(CTAB), dodecyl trimethyl ammonium chloride(DTAC). Under the condition of alkalescence, it is possible to separate the diaspore from the silicate minerals such as kaolinite, illite and pyrophyllite using quaternary ammonium salts as collector. Isoelectric points (IEP) of diaspore, kaolinite, pyrophyllite and illite are pH=6.0, 3.4, 2.3 and 3.2, respectively. Quaternary ammonium salts can change ζ-potential of the aluminosilicate minerals obviously. The flotation mechanisms were explained by ζ-potential and Fourier transform infrared spectrum (FT-IR) measurements. The results demonstrate that only electrostatic interaction takes place between aluminosilicate minerals (diaspore, kaolinite, pyrophyllite and illite) and quaternary ammonium salts.

  11. Ammonium addition inhibits 13C-methane incorporation into methanotroph membrane lipids in a freshwater sediment

    NARCIS (Netherlands)

    Nold, S.C.; Boschker, H.T.S.; Pel, R.; Laanbroek, H.J.

    1999-01-01

    To investigate the effect of ammonium addition on the species composition and activity of freshwater methane oxidizing bacteria, intact sediment cores were labeled with 13CH4 and incubated under ambient and elevated ammonium concentrations. After 7 days, methanotroph activity was assessed by quantif

  12. AMMONIUM TOXICITY AND NITRATE RESPONSE OF AXENICALLY GROWN DACTYLORHIZA-INCARNATA SEEDLINGS

    NARCIS (Netherlands)

    DIJK, E; ECK, N

    1995-01-01

    The response to ammonium- and nitrate-nitrogen of seedlings of the calcicole orchid species Dactylorhiza incarnata (L.) Soo was tested in axenic in vitro culture of c. 3-month-old protocorms. A pronounced toxicity of ammonium ions was observed. Seedlings raised from plants of a coastal population (f

  13. Novel carbohydrate-based chiral ammonium ionic liquids derived from isomannide

    DEFF Research Database (Denmark)

    Kumar, Vineet; Pei, Cao; Olsen, Carl E.;

    2008-01-01

    This report describes the synthesis and characterization of novel carbohydrate-based chiral ammonium ionic liquids using isomannide as a biorenewable substrate. The diastereomeric interactions of these chiral ammonium ionic liquids with racemic Mosher's acid salt have been studied using NMR, which...

  14. Nitrogen phosphoric fertilizer production technology on the base of Central Kyzylkum phosphorites and ammonium nitrate melt

    OpenAIRE

    Shavkat Namazov; Akhmed Reymov; Nazarkul Pirmanov; Rashid Kurbaniyazov

    2012-01-01

    The process of obtaining nitrogen phosphoric fertilizer by introduction Central Kyzylkum phosphates and ammonium nitrate melt is studied. On the base of these results production technology diagram for nitrogen phosphoric fertilizer is offered. The given technology was approved and developed at the functioning devices of OJSC “NAVOIAZOT” ammonium nitrate shop.

  15. Nitrogen phosphoric fertilizer production technology on the base of Central Kyzylkum phosphorites and ammonium nitrate melt

    Directory of Open Access Journals (Sweden)

    Shavkat Namazov

    2012-11-01

    Full Text Available The process of obtaining nitrogen phosphoric fertilizer by introduction Central Kyzylkum phosphates and ammonium nitrate melt is studied. On the base of these results production technology diagram for nitrogen phosphoric fertilizer is offered. The given technology was approved and developed at the functioning devices of OJSC “NAVOIAZOT” ammonium nitrate shop.

  16. Nitrogen removal by autotrophic ammonium oxidizing bacteria enrichment under anaerobic conditions

    Directory of Open Access Journals (Sweden)

    Pongsak (Lek Noophan

    2008-07-01

    Full Text Available Sludge from an anoxic tank at the centralized wastewater treatment plant, Nong Khaem, Bangkok, Thailand, was inoculatedin an anaerobic sequencing batch reactor (ASBR. The optimal compositions and operating conditions of the stock of autotrophic ammonium oxidizing bacteria medium were determined. The process of oxidizing ammonium with bacteria under anaerobic conditions is often referred to as the Anammox process (NO2- to N2 gas, using NH4+ as the electron donor and NO2- as the electron acceptor. The startup period for the anammox culture took more than three months. With ammoniumand nitrite concentration ratios of 1:1.38 and 1:1.6, the nitrogen conversion rate zero order. Fluorescent in situ hybridization(FISH was used to identify specific autotrophic ammonium oxidizing bacteria (Nitrosomonas spp., Candidatus Brocadia anammoxidans, and Candidatus Kuenenia stuttgartiensis. Results from this work demonstrated a shift in the species of ammonium oxidizing bacteria from Nitrosomonas spp. to Candidati Brocadia anammoxidans and Kuenenia stuttgartiensis, with increased ammonium concentrations from 3 mM to 15 mM. Under NH4+:NO2- ratios of 1:1.38 and 1:1.6 the ammoniumoxidizing bacteria were able to remove both ammonium and nitrite simultaneously. The specific nitrogen removal rate of theanammox bacteria (Candidati Brocadia anammoxidans and Kuenenia stuttgartiensis was significantly higher than that of anaerobic ammonium oxidizing bacteria (Nitrosomonas spp.. Anaerobic ammonium oxidizing bacteria (Candidati Brocadia anammoxidans and Kuenenia stuttgartiensis are strict anaerobes.

  17. Alkali metal and ammonium chlorides in water and heavy water (binary systems)

    CERN Document Server

    Cohen-Adad, R

    1991-01-01

    This volume surveys the data available in the literature for solid-fluid solubility equilibria plus selected solid-liquid-vapour equilibria, for binary systems containing alkali and ammonium chlorides in water or heavy water. Solubilities covered are lithium chloride, sodium chloride, potassium chloride, rubidium chloride, caesium chloride and ammonium chloride in water and heavy water.

  18. 77 FR 21527 - Ammonium Nitrate From Russia: Correction to Notice of Opportunity To Request Administrative Review

    Science.gov (United States)

    2012-04-10

    ...; Opportunity To Request Administrative Review, 77 FR 63 (April 2, 2012). This notice serves as a correction to... International Trade Administration Ammonium Nitrate From Russia: Correction to Notice of Opportunity To Request... of the antidumping duty orders and inadvertently omitted Ammonium Nitrate from Russia, POR...

  19. Preparation and Application of Perchloric Acid Supported on Alumina (Al2O3-HCIO4) to the Synthesis of α-(α-Amidobenzyl)-β-naphthols

    Institute of Scientific and Technical Information of China (English)

    SHATERIAN,Hamid Reza; KHORAMI,Fahimeh; AMIRZADEH,Azita; GHASHANG,Majid

    2009-01-01

    Preparation of perchloric acid supported on alumina and its primary application as a solid supported heterogeneous catalyst to the synthesis of α-(α-amidobenzyl)-β-naphthols by a one-pot,three-component condensation of benzaldehydes,β-naphthol and acetamide or benzamide under thermal solvent-free conditions were described.The present methodology offers several advantages such as simple procedure,shorter reaction time,and excellent yields.

  20. Removal of ammonium ions from wastewater: A short review in development of efficient methods

    Directory of Open Access Journals (Sweden)

    V.K. Gupta

    2015-04-01

    Full Text Available Ammonium ions wastewater pollution has become one of the most serious environmental problems today. The treatment of ammonium ions is a special concern due to their recalcitrance and persistence in the environment. In recent years, various methods for ammonium ion removal from wastewater have been extensively studied. This paper reviews the current methods that have been used to treat ammonium ion wastewater and evaluates these techniques. These technologies include ion exchange, adsorption, biosorption, wet air oxidation, biofiltration, diffused aeration, nitrification and denitrification methods. About 75 published studies (1979-2015 are reviewed in this paper. It is evident from the literature survey articles that ion exchange, adsorption and biological technology are the most frequently studied for the treatment of ammonium ion wastewater.

  1. Kinetics Analysis on Mixing Calcination Process of Fly Ash and Ammonium Sulfate

    Institute of Scientific and Technical Information of China (English)

    Peng Wang; Laishi Li; Dezhou Wei

    2014-01-01

    abstract The further development of the extraction of alumina that is produced in the calcination process of ammonium sulfate mixed with fly ash was limited because of the lack of systematic theoretical study. In order to aggrandize the research of the calcination process, the kinetics and reaction mechanism of the calcinations were studied. The result suggests that there are two stages in the calcination process, and the alumina extraction rate increases swiftly in the initial stage, but slows down increasing in the later stage. The apparent activation energy of the initial and later stages equals to 13.31 and 35.65 kJ·mol-1, respectively. In the initial stage, ammonium sulfate reacts directly with mullite in the fly ash to form ammonium aluminum sulfate, while in the later stage, alumi-num sulfate is formed by the reaction between ammonium aluminum sulfate and ammonium sulfate.

  2. The Investigation of Magnesium Perchlorate/Iron Phase-mineral Mixtures as a Possible Source of Oxygen and Chlorine Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars

    Science.gov (United States)

    Sutter, B.; Heil, E.; Archer, P. D.; Ming, D. W.; Eigenbrode, J. L.; Franz, H. B.; Glavin, D. P.; McAdam, A. C.; Mahaffy, P. R.; Niles, P. B.; Stern, J. C.; Navarro-Gonzalez, R.; McKay, C. P.

    2014-01-01

    The Sample Analysis at Mars (SAM) instrument onboard the Curiosity rover detect-ed O2 and HCl gas releases from the Rocknest (RN) eolian bedform and the John Klein (JK) and Cumber-land (CB) drill hole materials in Gale Crater (Fig. 1) [1,2]. Chlorinated hydrocarbons have also been detect-ed by the SAM quadrupole mass spectrometer (QMS) and gas chromatography/mass spectrometer (GCMS) [1,2,3,4]. These detections along with the detection of perchlorate (ClO4(-)) by the Mars Phoenix Lander's Wet Chemistry Laboratory (WCL) [5] suggesting perchlo-rate is a possible candidate for evolved O2 and chlorine species. Laboratory thermal analysis of individual per-chlorates has yet to provide an unequivocal tempera-ture match to the SAM O2 and HCl release data [1,2]. Catalytic reactions of Fe phases in the Gale Crater ma-terial with perchlorates can potentially reduce the de-composition temperatures of these otherwise pure per-chlorate/chlorate phases [e.g., 6,7]. Iron mineralogy found in the Rocknest materials when mixed with Ca-perchlorate was found to cause O2 release temperatures to be closer match to the SAM O2 release data and enhance HCl gas releases. Exact matches to the SAM data has unfortnunately not been achieved with Ca-perchlorate-Fe-phase mixtures [8]. The effects of Fe-phases on magnesium perchlorate thermal decomposi-tion release of O2 and HCl have not been evaluated and may provide improved matches to the SAM O2 and HCl release data. This work will evaluate the thermal decomposition of magnesium perchlorate mixed with fayalite/magnetite phase and a Mauna Kea palagonite (HWMK 919). The objectives are to 1) summarize O2 and HCl releases from the Gale Crater materials, and 2) evaluate the O2 and HCl releases from the Mg-perchlorate + Fe phase mixtures to determine if Mg-perchlorate mixed with Fe-phases can explain the Gale Crater O2 and HCl releases.

  3. Interaction between Ammonium Toxicity and Green Tide Development Over Seagrass Meadows: A Laboratory Study

    Science.gov (United States)

    Moreno-Marín, Francisco; Vergara, Juan J.; Pérez-Llorens, J. Lucas; Pedersen, Morten F.; Brun, Fernando G.

    2016-01-01

    Eutrophication affects seagrasses negatively by increasing light attenuation through stimulation of biomass of fast-growing, bloom-forming algae and because high concentrations of ammonium in the water can be toxic to higher plants. We hypothesized nevertheless, that moderate amounts of nitrophilic macroalgae that coexists with seagrasses under eutrophic conditions, can alleviate the harmful effects of eutrophication on seagrasses by reducing ammonium concentrations in the seawater to non-toxic levels because such algae have a very large capacity to take up inorganic nutrients. We studied therefore how combinations of different ammonium concentrations (0, 25 and 50 μM) and different standing stocks of macroalgae (i.e. 0, 1 and 6 layers of Ulva sp.) affected survival, growth and net production of the seagrass Zostera noltei. In the absence of Ulva sp., increasing ammonium concentrations had a negative influence on the performance of Z. noltei. The presence of Ulva sp. without ammonium supply had a similar, but slightly smaller, negative effect on seagrass fitness due to light attenuation. When ammonium enrichment was combined with presence of Ulva sp., Ulva sp. ameliorated some of negative effects caused by high ammonium availability although Ulva sp. lowered the availability of light. Benthic microalgae, which increased in biomass during the experiment, seemed to play a similar role as Ulva sp.–they contributed to remove ammonium from the water, and thus, aided to keep the ammonium concentrations experienced by Z. noltei at relatively non-toxic levels. Our findings show that moderate amounts of drift macroalgae, eventually combined with increasing stocks of benthic microalgae, may aid seagrasses to alleviate toxic effects of ammonium under eutrophic conditions, which highlights the importance of high functional diversity for ecosystem resistance to anthropogenic disturbance. PMID:27035662

  4. Interaction between Ammonium Toxicity and Green Tide Development Over Seagrass Meadows: A Laboratory Study.

    Science.gov (United States)

    Moreno-Marín, Francisco; Vergara, Juan J; Pérez-Llorens, J Lucas; Pedersen, Morten F; Brun, Fernando G

    2016-01-01

    Eutrophication affects seagrasses negatively by increasing light attenuation through stimulation of biomass of fast-growing, bloom-forming algae and because high concentrations of ammonium in the water can be toxic to higher plants. We hypothesized nevertheless, that moderate amounts of nitrophilic macroalgae that coexists with seagrasses under eutrophic conditions, can alleviate the harmful effects of eutrophication on seagrasses by reducing ammonium concentrations in the seawater to non-toxic levels because such algae have a very large capacity to take up inorganic nutrients. We studied therefore how combinations of different ammonium concentrations (0, 25 and 50 μM) and different standing stocks of macroalgae (i.e. 0, 1 and 6 layers of Ulva sp.) affected survival, growth and net production of the seagrass Zostera noltei. In the absence of Ulva sp., increasing ammonium concentrations had a negative influence on the performance of Z. noltei. The presence of Ulva sp. without ammonium supply had a similar, but slightly smaller, negative effect on seagrass fitness due to light attenuation. When ammonium enrichment was combined with presence of Ulva sp., Ulva sp. ameliorated some of negative effects caused by high ammonium availability although Ulva sp. lowered the availability of light. Benthic microalgae, which increased in biomass during the experiment, seemed to play a similar role as Ulva sp.--they contributed to remove ammonium from the water, and thus, aided to keep the ammonium concentrations experienced by Z. noltei at relatively non-toxic levels. Our findings show that moderate amounts of drift macroalgae, eventually combined with increasing stocks of benthic microalgae, may aid seagrasses to alleviate toxic effects of ammonium under eutrophic conditions, which highlights the importance of high functional diversity for ecosystem resistance to anthropogenic disturbance. PMID:27035662

  5. Interaction between Ammonium Toxicity and Green Tide Development Over Seagrass Meadows: A Laboratory Study.

    Directory of Open Access Journals (Sweden)

    Francisco Moreno-Marín

    Full Text Available Eutrophication affects seagrasses negatively by increasing light attenuation through stimulation of biomass of fast-growing, bloom-forming algae and because high concentrations of ammonium in the water can be toxic to higher plants. We hypothesized nevertheless, that moderate amounts of nitrophilic macroalgae that coexists with seagrasses under eutrophic conditions, can alleviate the harmful effects of eutrophication on seagrasses by reducing ammonium concentrations in the seawater to non-toxic levels because such algae have a very large capacity to take up inorganic nutrients. We studied therefore how combinations of different ammonium concentrations (0, 25 and 50 μM and different standing stocks of macroalgae (i.e. 0, 1 and 6 layers of Ulva sp. affected survival, growth and net production of the seagrass Zostera noltei. In the absence of Ulva sp., increasing ammonium concentrations had a negative influence on the performance of Z. noltei. The presence of Ulva sp. without ammonium supply had a similar, but slightly smaller, negative effect on seagrass fitness due to light attenuation. When ammonium enrichment was combined with presence of Ulva sp., Ulva sp. ameliorated some of negative effects caused by high ammonium availability although Ulva sp. lowered the availability of light. Benthic microalgae, which increased in biomass during the experiment, seemed to play a similar role as Ulva sp.--they contributed to remove ammonium from the water, and thus, aided to keep the ammonium concentrations experienced by Z. noltei at relatively non-toxic levels. Our findings show that moderate amounts of drift macroalgae, eventually combined with increasing stocks of benthic microalgae, may aid seagrasses to alleviate toxic effects of ammonium under eutrophic conditions, which highlights the importance of high functional diversity for ecosystem resistance to anthropogenic disturbance.

  6. Competition for Ammonium between Plant-Roots and Nitrifying and Heterotrophic Bacteria and the Effects of Protozoan Grazing

    NARCIS (Netherlands)

    Verhagen, F.J.M.; Laanbroek, H.J.; Woldendorp, J.W.

    1995-01-01

    The competition for limiting amounts of ammonium between the chemolithotrophic ammonium-oxidizing species Nitrosomonas europaea, the heterotrophic species Arthrobacter globiformis and roots of Plantago lanceolata (Ribwort plantain) was studied in a series of model systems of increasing complexity, i

  7. Environmental Factors Affecting Ammonium Oxidation Under Iron Reducing Conditions

    Science.gov (United States)

    Jaffe, P. R.; Huang, S.; Ruiz-Urigüen, M.

    2014-12-01

    Ammonium (NH4+) oxidation coupled to iron (Fe) reduction in the absence of oxygen and nitrate/nitrite (NO3-/NO2-) has been reported by several investigators and referred to as Feammox. Feammox is a biological reaction, where Fe(III) is the electron acceptor, which is reduced to Fe(II), and NH4+ is the electron donor, which is oxidized to NO2-. Through a 180-day anaerobic incubation experiment, and using PCR-DGGE, 454-pyosequecing and qPCR analysis, we have shown that an Acidimicrobiaceae bacterium A6, a previously unreported species in the Acidimicrobiaceae family, might be either responsible or plays a key role in the Feammox process, We have enriched these Feammox bacteria (65.8% in terms of cell numbers) in a membrane reactor, and isolated the pure Acidimicrobiaceae bacterium A6 strain in an autotrophic medium. In samples collected and then incubated from a series of local wetland-, upland-, as well as storm-water detention pond-sediments, Feammox activity was only detected in acidic soil environments that contain Fe oxides. Using primers we developed for this purpose, Acidimicrobiaceae bacterium A6 was detected in all incubations where Feammox was observed. Anaerobic incubations of Feammox enrichment cultures adjusted to different pH, revealed that the optimal pH for Feammox is 4 ~ 5, and the reaction does not proceed when pH > 7. Feammox was still proceeding at pH as low as 2. In Feammox culture amended with different Fe(III) sources, Feammox reaction proceeded only when Fe oxides (ferrihydrite or goethite ) were supplied, whereas samples incubated with ferric chloride or ferric citrate showed no measurable NH4+ oxidation. Furthermore, we have also determined from incubation experiments conducted with a temperature gradient (10 ~ 35℃), that the Feammox process was active when the temperature is above 15℃, and the optimal temperature is 20℃. Incubations of enrichment culture with 79% Feammox bacteria appeared to remove circa 8% more NH4+ at 20ºC than at

  8. Quaternary ammonium derivatives as spasmolytics for irritable bowel syndrome.

    Science.gov (United States)

    Evangelista, S

    2004-01-01

    Quaternary ammonium derivatives such as cimetropium, n-butyl scopolammonium, otilonium and pinaverium bromide have been discovered and developed as potent spasmolytics of the gastrointestinal tract. Their pharmacological activity has been proven in both "in vivo" and "in vitro" studies of hypermotility. "In vitro" experiments showed that they possess antimuscarinic activity at nM level but only pinaverium and otilonium are endowed with calcium channel blocker properties. These latter compounds relaxed the gastrointestinal smooth muscle mainly through a specific inhibition of calcium ion influx through L-type voltage operated calcium channels. Molecular pharmacology trials have indicated that pinaverium and otilonium can bind specific subunits of the calcium channel in the external surface of the plasma membrane and in this way they block the machinery of the contraction. Recent evidence showed that otilonium is able to bind tachykinin NK(2) receptors and not only inhibits one of the major contractile agents but can reduce the activation of afferent nerves devoted to the passage of sensory signals from the periphery to the central nervous system. Thanks to their typical physico-chemical characteristics, they are poorly absorbed by the systemic circulation and generally remain in the gastrointestinal tract where they exert the muscle relaxant activity by a local activity. Some differences exists in the absorption among these compounds: both n-butyl scopolammonium and cimetropium are partially taken up in the bloodstream, pinaverium has a low absorption (8-10 %) but is endowed with an excellent hepato-biliary excretion and otilonium, which has the lowest absorption (3 %), is almost totally excreted by faeces. Quaternary ammonium derivatives are widely used for the treatment of irritable bowel syndrome and recent meta-analyses have supported their efficacy in this disease. Due to its therapeutic index, the use of n-butyl scopolammonium is more indicated to treat acute

  9. Biological Reduction of Perchlorate and Optimization%生物法降解高氯酸盐及其优化研究

    Institute of Scientific and Technical Information of China (English)

    钱慧静; 奚胜兰; 何平; 徐新华

    2009-01-01

    The potential of bioremediation to treat perchlorate-contaminated water by acclimating anaerobic activated sludge was investigated in this study. Factors such as carbon source,initial pH,temperature,domesticated sludge concentration and dissolved oxygen affecting the removal of perchlorate were studied in detail by shaking-bottle point tests using acetate as carbon source. Results showed that 50 mg/L perchlorate was completely reduced by 1.0 g of domesticated sludge added with 1.2 g/L of acetate under the conditions of 35℃ and initial pH 8.0. Dissolved oxygen in the system would restrain the reduction of perchlorate. In addition,column bioreactor was used to treat perchlorate continuously,with the minimum residence time of 6 h.%利用经过驯化处理的厌氧活性污泥来处理高氯酸盐废水,以醋酸根为碳源,通过摇床实验考察了碳源浓度、pH值、生长温度、泥量和溶解氧等因素对高氯酸盐降解率的影响,初步确定最佳反应条件.结果表明,在35℃、初始pH值为 8.0的条件下,添加1.2 g/L的醋酸根,1.0 g厌氧培养的活性污泥能将50 mg/L的高氯酸盐完全降解.体系中的溶解氧会抑制高氯酸盐的降解.此外,还考察了生物膜柱反应器连续处理高氯酸盐模拟废水的效果,结果表明完全降解高氯酸盐的最小停留时间为6 h.

  10. Synthesis and Antimicrobial Properties of the Novel Fluorinated Bis-ammonium Salts with Two Primary Amine Groups

    Institute of Scientific and Technical Information of China (English)

    Jian Bin LUO; Qiang WANG; Hong TAN; Jie Hua LI; Yin Ping ZHONG

    2006-01-01

    In order to resolve the increasing resistance phenomena of the Gram-negative bacteria against single chain quaternary ammonium salts (QAS), lysine with a pedant fluorinated bis-ammonium salts was synthesized and its antimicrobial properties were evaluated in this work.The novel fluorinated bis-ammonium salts shows similar activity with conventional single chain quaternary ammonium salts against Gram-positive bacteria but stronger activity against Gram-negative bacteria and yeast compared with the single chained counterpart.

  11. Relating dynamic conditions to the performance of biological rapid sand filters used to remove ammonium, iron, and manganese from drinking water

    DEFF Research Database (Denmark)

    Lee, Carson; Albrechtsen, Hans-Jørgen; Smets, Barth F.;

    and media samples were collected throughout the depth of the column and over the operational cycle of the columns. Substrate analysis included ammonium, nitrite, nitrate, iron, and manganese. Qpcr analysis were also performed to quantify ammonium oxidizing bacteria (AOBs), ammonium oxidizing archea ( AOAs...... on the roles of both Ammonium oxidizing bacteria (AOBs) and Ammonium oxidizing archea (AOAs) in the biological removal of ammonium in rapid sand filters and how varying substrate loadings and operating conditions can affect the biological performance of these filters....

  12. Paleosols in central Illinois as potential sources of ammonium in groundwater

    Science.gov (United States)

    Glessner, J.J.G.; Roy, W.R.

    2009-01-01

    Glacially buried paleosols of pre-Holocene age were evaluated as potential sources for anomalously large concentrations of ammonium in groundwater in East Central Illinois. Ammonium has been detected at concentrations that are problematic to water treatment facilities (greater than 2.0 mg/L) in this region. Paleosols characterized for this study were of Quaternary age, specifically Robein Silt samples. Paleosol samples displayed significant capacity to both store and release ammonium through experiments measuring processes of sorption, ion exchange, and weathering. Bacteria and fungi within paleosols may significantly facilitate the leaching of ammonium into groundwater by the processes of assimilation and mineralization. Bacterial genetic material (DNA) was successfully extracted from the Robein Silt, purified, and amplified by polymerase chain reaction to produce 16S rRNA terminal restriction fragment length polymorphism (TRFLP) community analyses. The Robein Silt was found to have established diverse and viable bacterial communities. 16S rRNA TRFLP comparisons to well-known bacterial species yielded possible matches with facultative chemolithotrophs, cellulose consumers, nitrate reducers, and actinomycetes. It was concluded that the Robein Silt is both a source and reservoir for groundwater ammonium. Therefore, the occurrence of relatively large concentrations of ammonium in groundwater monitoring data may not necessarily be an indication of only anthropogenic contamination. The results of this study, however, need to be placed in a hydrological context to better understand whether paleosols can be a significant source of ammonium to drinking water supplies. ?? 2009 National Ground Water Association.

  13. Preparation and characteristic research of anhydrous magnesium chloride with dehydrated ammonium carnallite

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ning-bo; CHEN Bai-zhen; HE Xin-kuai; LI Yi-bing

    2006-01-01

    Taking the saline lake bischofite and NH4Cl that was removed with the ammonia method and continuwas synthesized. And then the ammonium carnallite was dehydrated to some extent at 160℃ for 4 h. Ammonium carnallite reacted with ammonia at 240℃ for 150 min and the ammonation ammonium carnallite was produced. Finally, the ammonation ammonium carnallite was calcined at 750℃ into anhydrous magnesium chloride containing only 0.1% (mass fraction) of MgO. On the other hand, dehydrated ammonium carnallite was mixed with the solid ammonium chloride at mass ratio 1:4 at high temperature and with the differential pressure of HN3 above 30.5 kPa. The dehydrated ammonium carnallite of mixture was dehydrated at 410℃, and then calcined at 700℃ into anhydrous magnesium chloride with only 0. 087% (mass fraction) of MgO. X-ray diffraction and electron microscopy analysis results prove that anhydrous magnesium chloride obtained by both methods hasn't mixed phases, the particle is large and even has good dispersion, which is suitable for preparation of metal magnesium in the electrolysis.

  14. Coastal water column ammonium and nitrite oxidation are decoupled in summer

    Science.gov (United States)

    Heiss, Elise M.; Fulweiler, Robinson W.

    2016-09-01

    Water column nitrification is a key process in the nitrogen cycle as it links reduced and oxidized forms of nitrogen and also provides the substrate (nitrate) needed for reactive nitrogen removal by denitrification. We measured potential water column ammonium and nitrite oxidation rates at four sites along an estuary to continental shelf gradient over two summers. In most cases, nitrite oxidation rates outpaced ammonium oxidation rates. Overall, ammonium and nitrite oxidation rates were higher outside of the estuary, and this trend was primarily driven by higher oxidation rates in deeper waters. Additionally, both ammonium and nitrite oxidation rates were impacted by different in situ variables. Ammonium oxidation rates throughout the water column as a whole were most positively correlated to depth and salinity and negatively correlated to dissolved oxygen and light. In contrast, nitrite oxidation rates throughout the water column were negatively correlated with light and pH. Multivariate regression analysis revealed that while both surface (20 m) ammonium oxidation rates were most strongly predicted by depth and light, surface rates were also regulated by salinity and deep rates by temperature. Surface (20 m) nitrite oxidation rates. These results support the growing body of evidence that ammonium oxidation and nitrite oxidation are not always coupled, should be measured separately, and are influenced by different environmental conditions.

  15. Root ABA Accumulation Enhances Rice Seedling Drought Tolerance under Ammonium Supply: Interaction with Aquaporins

    Science.gov (United States)

    Ding, Lei; Li, Yingrui; Wang, Ying; Gao, Limin; Wang, Min; Chaumont, François; Shen, Qirong; Guo, Shiwei

    2016-01-01

    In previous studies, we demonstrated that ammonium nutrition enhances the drought tolerance of rice seedlings compared to nitrate nutrition and contributes to a higher root water uptake ability. It remains unclear why rice seedlings maintain a higher water uptake ability when supplied with ammonium under drought stress. Here, we focused on the effects of nitrogen form and drought stress on root abscisic acid (ABA) concentration and aquaporin expression using hydroponics experiments and stimulating drought stress with 10% PEG6000. Drought stress decreased the leaf photosynthetic rate and stomatal conductivity and increased the leaf temperature of plants supplied with either ammonium or nitrate, but especially under nitrate supply. After 4 h of PEG treatment, the root protoplast water permeability and the expression of root PIP and TIP genes decreased in plants supplied with ammonium or nitrate. After 24 h of PEG treatment, the root hydraulic conductivity, the protoplast water permeability, and the expression of some aquaporin genes increased in plants supplied with ammonium compared to those under non-PEG treatment. Root ABA accumulation was induced by 24 h of PEG treatment, especially in plants supplied with ammonium. The addition of exogenous ABA decreased the expression of PIP and TIP genes under non-PEG treatment but increased the expression of some of them under PEG treatment. We concluded that drought stress induced a down-regulation of aquaporin expression, which appeared earlier than did root ABA accumulation. With continued drought stress, aquaporin expression and activity increased due to root ABA accumulation in plants supplied with ammonium.

  16. The ammonium content in the Malayer igneous and metamorphic rocks (Sanandaj-Sirjan Zone, Western Iran)

    Science.gov (United States)

    Ahadnejad, Vahid; Hirt, Ann Marie; Valizadeh, Mohammad-Vali; Bokani, Saeed Jabbari

    2011-04-01

    The ammonium (NH4+) contents of the Malayer area (Western Iran) have been determined by using the colorimetric method on 26 samples from igneous and metamorphic rocks. This is the first analysis of the ammonium contents of Iranian metamorphic and igneous rocks. The average ammonium content of metamorphic rocks decreases from low-grade to high-grade metamorphic rocks (in ppm): slate 580, phyllite 515, andalusite schist 242. In the case of igneous rocks, it decreases from felsic to mafic igneous types (in ppm): granites 39, monzonite 20, diorite 17, gabbro 10. Altered granitic rocks show enrichment in NH4+ (mean 61 ppm). The high concentration of ammonium in Malayer granites may indicate metasedimentary rocks as protoliths rather than meta-igneous rocks. These granitic rocks (S-types) have high K-bearing rock-forming minerals such as biotite, muscovite and K-feldspar which their potassium could substitute with ammonium. In addition, the high ammonium content of metasediments is probably due to inheritance of nitrogen from organic matter in the original sediments. The hydrothermally altered samples of granitic rocks show highly enrichment of ammonium suggesting external sources which intruded additional content by either interaction with metasedimentary country rocks or meteoritic solutions.

  17. Antibacterial Activity of Dental Cements Containing Quaternary Ammonium Polyethylenimine Nanoparticles

    Directory of Open Access Journals (Sweden)

    Nurit Beyth

    2012-01-01

    Full Text Available Glass ionomer cements (GICs are commonly used for cementing full cast crown restorations. Regrettably, although the dental cements fill the gap between the tooth and the crown, bacterial microleakage may occur, resulting in secondary caries. As microleakage cannot be completely prevented, GICs possessing antibacterial properties are in demand. In the present study the antibacterial activity of insoluble, cross-linked quaternary ammonium polyethylenimine (QPEI nanoparticles incorporated at 1% w/w in two clinically available GICs were studied. The antibacterial activity was tested against Streptococcus mutans and Lactobacillus casei using the direct contact test (DCT and the agar diffusion test (ADT. Using the direct contact test, antibacterial activity (<0.05 was found in both tested GICs with incorporated QPEI nanoparticles, the effect lasting for at least one month. However, the ADT showed no inhibition halo in the test bacteria, indicating that the antimicrobial nanoparticles do not diffuse into the agar. The results show that the incorporation of QPEI nanoparticles in glass ionomer cements has a long-lasting antibacterial effect against Streptococcus mutans and Lactobacillus casei. Changing the antibacterial properties of glass ionomer cements by incorporating QPEI antibacterial nanoparticles may prolong the clinical performance of dental crowns.

  18. Synthesis and characterization of ammonium phosphate fertilizers with boron

    Directory of Open Access Journals (Sweden)

    ANGELA MAGDA

    2010-07-01

    Full Text Available The concentration of boron, an essential micronutrient for plants, presents a narrow range between deficiency and toxicity. In order to provide the boron requirement for plants, and to avoid toxicity problems, boron compounds are mixed with basic fertilizers. Sodium borate pentahydrate was used as a boron source. Ammonium orthophosphates fertilizers with boron were prepared by neutralizing phosphoric acid with ammonia and addition of variable amounts of sodium tetraborate pentahydrate to the reaction mixture at a NH3:H3PO4 molar ratio of 1.5. The fertilizers obtained with boron contents ranging from 0.05 to 1 % (w/w were fully characterized by chemical analysis, thermal analysis, X-ray diffraction and infrared spectrophotometry. The studies showed that up to 500 °C, regardless of the boron content, no significant changes concerning thermal stability and nutritional properties occurred. Above 500 °C, an increase of thermal stability with an increase of the boron content was observed. X-Ray diffraction of a heat-treated sample containing 5 % (w/w boron indicated the appearance of boron orthophosphate, BPO4, as a new crystalline phase, and the disappearance of the previous structures above 500 °C, which explains the increase in thermal stability.

  19. Alanine synthesis from glyceraldehyde and ammonium ion in aqueous solution

    Science.gov (United States)

    Weber, A. L.

    1985-01-01

    The formation of alanine (ala) form C(14)-glyceraldehyde and ammonium phosphate in the presence or absence of a thiol is reported. At ambient temperature, ala synthesis was six times more rapid in the presence of 3-mercaptopropionic acid than in its absence (0.6 and 0.1 percent, respectively, after 60 days). Similarly, the presence of another thiol, N-acetylcysteinate, increased the production of ala, as well as of lactate. The reaction pathway of thiol-catalyzed synthesis of ala, with the lactic acid formed in a bypath, is suggested. In this, dehydration of glyceraldehyde is followed by the formation of hemithioacetal. In the presence of ammonia, an imine is formed, which eventually yields ala. This pathway is consistent with the observation that the rate ratio of ala/lactate remains constant throughout the process. The fact that the reaction takes place under anaerobic conditions in the presence of H2O and with the low concentrations of simple substrates and catalysts makes it an attractive model prebiotic reaction in the process of molecular evolution.

  20. Evaluation of a cesium adsorbent grafted with ammonium 12-molybdophosphate

    Science.gov (United States)

    Shibata, Takuya; Seko, Noriaki; Amada, Haruyo; Kasai, Noboru; Saiki, Seiichi; Hoshina, Hiroyuki; Ueki, Yuji

    2016-02-01

    A fibrous cesium (Cs) adsorbent was developed using radiation-induced graft polymerization with a cross-linked structure containing a highly stable adsorption ligand. The ligand, ammonium 12-molybdophosphate (AMP), was successfully introduced onto the fibrous polyethylene trunk material. The resulting Cs adsorbent contained 36% nonwoven fabric polyethylene (NFPE), 1% AMP, 2% triallyl isocyanurate (TAIC) and 61% glycidyl methacrylate (GMA). The adsorbent's Cs adsorption capacity was evaluated using batch and column tests. It was determined that the adsorbent could be used in a wide pH range. The amount of desorbed molybdenum, which can be used as an estimate for AMP stability on the Cs adsorbent, was minimized at the standard drinking water pH range of 5.8-8.6. Based from the inspection on the adherence of these results to the requirements set forth by the Food Sanitation Act by a third party organization, it can be concluded that the developed Cs adsorbent can be safely utilized for drinking water.

  1. Evaluation of ammonium polyphosphate fertilizer as a carrier of zinc

    International Nuclear Information System (INIS)

    Ammonium polyphosphate (APP) and diammonium orthophosphate (DAP) were evaluated as carriers of zinc in an Ultisol and a Vertisol. Surface applications of 65Zn along with urea or orthophosphate or pyrophosphate or polyphosphate to the two soils indicated very little movement of the radionuclide below 2 cm from surface in both soils on leaching with rain water. Greenhouse experiments with maize and red kidney beans grown in sequence in the two soils fertilized with APP and DAP both blended with 65Zn (as ZnSO4.7H2O) indicated that while the Zn fertilizer use efficiency of Zn-APP blend was significantly higher than that of Zn-DAP blend for maize, their residual value was equal for the succeeding bean crop. Experiments with maize-greengram sequence indicated superiority of Zn-APP blend only in Vertisol, while in Ultisol both the blends were equally effective. A field experiments with flooded rice indicated increased grain yield with application of Zn at 22 kg Zn ha-1. Neither P nor Zn application had any significant effect on straw yield. Grain and straw Zn concentrations increased significantly by the applications of both P and Zn. At zero or low levels of applied Zn, APP was significantly superior to DAP as a P source; while at higher dose of Zn, no significant difference was noted between the two P sources. (author). 18 refs, 5 tabs

  2. Rubidium, cesium and potassium sorption with magnesium-ammonium phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Leont' eva, G.V.; Tomchuk, T.K.

    1986-01-01

    The possibility for using magnesium-ammonium phosphate as a sorbent to separate Cs/sup +/, Rb/sup +/ and K/sup +/ ions is estimated. The sorbent composition is close to NH/sub 4/MgPO/sub 4/x6H/sub 2/O. Sorption isotherms have been removed under static conditions at 293+-2 K separately for Cs/sup +/, Rb/sup +/ and K/sup +/ ions. Determination of the separation coefficients of these Cs/sup +/-Rb/sup +/ and Rb/sup +/-K/sup +/ ion pairs (the ratio of the ions separated in the initial solution varies from 1:1 to 1:10) during their sorption by NH/sub 4/MgPO/sub 4/x6H/sub 2/O phosphate gave the following estimation of the values measured: P/sub Cs-Rb/=(30-156) and P/sub Rb-K/=(7-15). Taking into account high values of the separation coefficients and good reversibility of the ion exchange process NH/sub 4//sup +/reversibleMe/sup +/(Me/sup +/=Cs/sup +/, Rb/sup +/, K/sup +/) by phosphate and with the struvite structure, it is possible to recommend this sorbent for practical application.

  3. Photoluminescence from silicon nanoparticles embedded in ammonium silicon hexafluoride

    Energy Technology Data Exchange (ETDEWEB)

    Kalem, Seref [UEKAE, National Research Institute of Electronics and Cryptology, Gebze 41470 Kocaeli (Turkey); Werner, Peter; Becker, Michael; Zakharov, Nikolai [Department of Experimental Physics, Max-Planck-Institute, Halle(Saale) (Germany); Talalaev, Vadim [ZIK ' SiLi-nano' , Martin-Luther-Universitaet (Halle), Karl-Freiherr-von-Fritsch-Strasse 3 D-06120 Halle (Germany); Arthursson, Oerjan, E-mail: s.kalem@uekae.tubitak.gov.tr [Microtechnology and Nanosciences Department, Chalmers University of Technology, Goeteborg (Sweden)

    2010-10-29

    Silicon (Si) nanoparticles (NPs) were synthesized by transforming a Si wafer surface to ammonium silicon hexafluoride (ASH) or (NH{sub 4}){sub 2}SiF{sub 6} under acid vapor treatment. Si-NPs which were found to be embedded within the polycrystalline (ASH) layer exhibit a strong green-orange photoluminescence (PL). Differential PL measurements revealed a major double component spectrum consisting of a broad band associated with the ASH-Si wafer interfacial porous oxide layer and a high energy band attributable to Si-NPs embedded in the ASH. The origin of the latter emission can be explained in terms of quantum/spatial confinement effects probably mediated by oxygen related defects in or around Si-NPs. Although Si-NPs are derived from the interface they are much smaller in size than those embedded within the interfacial porous oxide layer (SiO{sub x}, x > 1.5). Transmission electron microscopy (TEM) combined with Raman scattering and Fourier transformed infrared (FTIR) analysis confirmed the presence of Si-NP and Si-O bondings pointing to the role of oxygen related defects in a porous/amorphous structure. The presence of oxygen of up to 4.5 at.% in the (NH{sub 4}){sub 2}SiF{sub 6} layer was confirmed by energy dispersive spectroscopy (EDS) analysis.

  4. Synthesis, Characterization and Thermal Decomposition Mechanism of Cetyltrimethyl Ammonium Tetrathiotungstate

    Institute of Scientific and Technical Information of China (English)

    Gaojun An; Yunqi Liu; Yongming Chai; Hongyan Shang; Chenguang Liu

    2006-01-01

    The synthesis, characterization and thermal decomposition mechanism of cetyltrimethyl ammonium tetrathiotungstate (CTriMATT) were studied herein. The as-synthesized CTriMATT was characterized by Elemental analysis, X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Ultraviolet visible (UV-Vis) spectra. The results showed that the as-synthesized CTriMATT had high purity and good crystallinity. The introduction of alkyl groups induced a shift of the stretching vibration band of W-S bond to lower wavenumber, while it had no influence on the position of WS2-4. Thermogravimetric analysis (TG), differential thermal analysis (DTA) and in situ XRD characterizations revealed that CTriMATT began to decompose at 423 K in nitrogen and was converted to WS2 eventually. In addition,the decomposition product of CTriMATT at 673 K in nitrogen was characterized by N2 adsorption (BET)and scanning electron microscopy (SEM). The results demonstrated that WS2 with higher specific surface area, and pore volume could be obtained from the thermal decomposition of CTriMATT in nitrogen.

  5. Betaines and related ammonium compounds in chestnut (Castanea sativa Mill.).

    Science.gov (United States)

    Servillo, Luigi; Giovane, Alfonso; Casale, Rosario; Balestrieri, Maria Luisa; Cautela, Domenico; Paolucci, Marina; Siano, Francesco; Volpe, Maria Grazia; Castaldo, Domenico

    2016-04-01

    Chestnut fruits, being poor of simple sugars and consisting mainly of fibers and starch, are among the constituents of Mediterranean diet. While numerous studies report on content of proteins and amino acids in chestnut, no one has appeared so far on betaines, an important class of nitrogen compounds ubiquitous in plants for their protective action in response to abiotic stress. In this study, we analyzed by HPLC-ESI-tandem mass spectrometry, in fruits and flours of varieties of chestnut cultivated in Italy, the composition of betaines and ammonium compounds intermediates of their biosynthesis. Besides the parent amino acids, the compounds quantified were choline, glycerophosphocholine, phosphocholine, glycine betaine, N-methylproline, proline betaine (stachydrine), β-alanine betaine, 4-guanidinobutyric acid, trigonelline, N,N,N-trimethyllysine. Interestingly, some uncommon derivatives of pipecolic acid, such as N-methylpipecolic acid, 4-hydroxypipecolic acid and 4-hydroxy-N-methylpipecolic acid were identified for the first time in chestnut samples and characterized by MS(n) tandem mass spectrometry.

  6. Organomontmorillonites Modified with 2-Methacryloyloxy Ethyl Alkyl Dimethyl Ammonium Bromide

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-quan; WU Wen-hui

    2007-01-01

    Organomontmorillonites (organo-MMT) were synthesized by means of montmorillonites (MMT) modified with a series of 2-methacryloyloxy ethyl alkyl dimethyl ammonium bromide (MAAB) having different alkyl chain lengths as cationic surfactants through a cationic exchanging reaction, and were characterized by FTIR, TG, elemental analysis, and XRD. The microenvironment of the organic interlayer such as the orientation and arrangement of the alkyl chains of MAAB, as well as the properties of nanocomposite hydrogels, were also investigated. The amount of organic components absorbed on interlayer and the basal spacing of organo-MMT both increase with the increasing of alkyl length of MAAB. When carbon number of alkyl chain is in the region of 8 to 14, the alkyl chains between layers would adopt a disordered gauche conformation; while the carbon number is 16, an ordered all-trans conformation with a vertical orientation would be found together with the disordered gauche conformation according to the results of XRD and FTIR. Due to the difference of microenvironment of organic interlayer, the Young's moduli of the nanocomposite hydrogels increased as the alkyl chains of MAAB became longer.

  7. Interaction of ochratoxin A with quaternary ammonium beta-cyclodextrin.

    Science.gov (United States)

    Poór, Miklós; Kunsági-Máté, Sándor; Szente, Lajos; Matisz, Gergely; Secenji, Györgyi; Czibulya, Zsuzsanna; Kőszegi, Tamás

    2015-04-01

    Ochratoxin A (OTA) is a widely spread nephrotoxic food contaminant mycotoxin. Unfortunately, attenuation or prevention of the toxic effects of OTA is still an unresolved problem. Molecular inclusion of OTA by cyclodextrins (CDs) results in complexes with low stability. In the human organism, OTA exists mostly in the dianionic state (OTA(2-)). Therefore, our major goal was to develop a chemically modified cyclodextrin which gives a more stable complex with OTA than the previously published derivatives and which shows stronger preference towards OTA(2-). In our fluorescence spectroscopic study we demonstrate that quaternary ammonium beta-cyclodextrin (QABCD) fulfils both of these requirements. The calculated stability constant of the QABCD-OTA(2-) complex was 28,840 M(-1) (about 200-fold higher than that of the β-CD-OTA(2-) complex). We hypothesize, that QABCD may be a suitable tool for the decontamination of different OTA-contaminated drinks; furthermore, for alleviation of the toxic effects of OTA, such complex formation may reduce its absorption from the intestine.

  8. Thermochemical Properties and Decomposition Kinetics of Ammonium Magnesium Phosphate Monohydrate

    Institute of Scientific and Technical Information of China (English)

    WU,Jian; YUAN,Ai-Qun; HUANG,Zai-Yin; TONG,Zhang-Fa; CHEN,Jie; LIANG,Rong-Lan

    2007-01-01

    Ammonium magnesium phosphate monohydrate NH4MgPO4·H2O was prepared via solid state reaction at room temperature and characterized by XRD, FT-IR and SEM. Thermochemical study was performed by an isoperibol solution calorimeter, non-isothermal measurement was used in a multivariate non-linear regression analysis to determine the kinetic reaction parameters. The results show that the molar enthalpy of reaction above is (28.795±0.182) kJ/mol (298.15 K), and the standard molar enthalpy of formation of the title complex is (-2185.43±13.80)kJ/mol (298.15 K). Kinetics analysis shows that the second decomposition of NH4MgPO4·H2O acts as a double-step reaction: an nth-order reaction (Fn) with n=4.28, E1=147.35 kJ/mol, A1=3.63×1013 s-1 is followed by a second-order reaction (F2) with E2=212.71 kJ/mol, A2= 1.82×1018 s-1.

  9. Interaction of ochratoxin A with quaternary ammonium beta-cyclodextrin.

    Science.gov (United States)

    Poór, Miklós; Kunsági-Máté, Sándor; Szente, Lajos; Matisz, Gergely; Secenji, Györgyi; Czibulya, Zsuzsanna; Kőszegi, Tamás

    2015-04-01

    Ochratoxin A (OTA) is a widely spread nephrotoxic food contaminant mycotoxin. Unfortunately, attenuation or prevention of the toxic effects of OTA is still an unresolved problem. Molecular inclusion of OTA by cyclodextrins (CDs) results in complexes with low stability. In the human organism, OTA exists mostly in the dianionic state (OTA(2-)). Therefore, our major goal was to develop a chemically modified cyclodextrin which gives a more stable complex with OTA than the previously published derivatives and which shows stronger preference towards OTA(2-). In our fluorescence spectroscopic study we demonstrate that quaternary ammonium beta-cyclodextrin (QABCD) fulfils both of these requirements. The calculated stability constant of the QABCD-OTA(2-) complex was 28,840 M(-1) (about 200-fold higher than that of the β-CD-OTA(2-) complex). We hypothesize, that QABCD may be a suitable tool for the decontamination of different OTA-contaminated drinks; furthermore, for alleviation of the toxic effects of OTA, such complex formation may reduce its absorption from the intestine. PMID:25442535

  10. The Structure of Ammonium D,L-Tartrate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The single crystals of the title compound NH4+C4H5O6- (C4H9NO6, Mr = 167.1) were obtained from a hot aqueous solution containing L-glutamine and D,L-tartaric acid in mole ratio1:1.5. The crystal belongs to monoclinic space group P21/c with a = 7.646(2), b = 7.804(2), c = 11.502(3)?, β = 102.26(2)o, V = 670.7(3)?3, Z = 4, F(000) = 352, Dc = 1.655 g.cm-3, ((MoK() = 0.16 mm-1, R = 0.035, wR = 0.094 for 1028 observed reflections (I>2((I)). The enatiomeric anions of the tartrate with both (2S,3S)- and (2R,3R)-configuration co-exist in the unit cell. The carbon skeleton assumes a coplanar arrangement with a torsion angle of 181.5o. The three- dimensional H-bonding network exists in the crystal. While tartrate groups link each other by H-bonds between carboxyl and hydroxyl groups, the ammonium cations insert between the tartrate groups to form a sandwich-like crystal structure.

  11. Proton transfer in gas-phase ammonium dinitramide clusters

    Science.gov (United States)

    Alavi, Saman; Thompson, Donald L.

    2003-02-01

    Proton transfer in gaseous ammonium dinitramide (ADN) clusters up to (ADN)2 is studied by using density-functional theory. Proton transfer between the hydrogen dinitramide and ammonia units does not occur in the ADN monomer, rather the ammonia-hydrogen dinitramide complex is stabilized by strong hydrogen bonding. However, proton transfer between hydrogen dinitramide and ammonia is observed in the ADN dimer [NH3HN(NO2)2]2, ADN solvated with a single ammonia molecule [NH3NH(NO2)2]NH3, and ADN solvated with a hydrogen dinitramide molecule [NH3HN(NO2)2]HN(NO2)2. Structural changes in the complexes relative to the free molecules and the binding energies of the clusters are given. Using population analysis, the total electrostatic interaction energy in each cluster is calculated. The electrostatic energy is a measure that distinguishes between the ionic or hydrogen-bonded nature of the clusters. Some implications of proton transfer in ADN clusters on the decomposition mechanism of ADN are discussed.

  12. Atmospheric transport and wet deposition of ammonium in North Carolina

    Science.gov (United States)

    Walker, John T.; Aneja, Viney P.; Dickey, David A.

    Wet deposition and transport analysis has been performed for ammonium (NH 4+) in North Carolina, USA. Multiple regression analysis is employed to model the temporal trend and seasonality in monthly volume-weighted mean NH 4+ concentrations in precipitation from 1983 to 1996 at six National Atmospheric Deposition Program/National Trends Network (NADP/NTN) sites. A significant ( ppopulated network of swine and poultry operations. This trend is positively correlated with increasing ammonia (NH 3) emissions related to the vigorous growth of North Carolina's swine population since 1990, particularly in the state's Coastal Plain region. A source-receptor regression model, which utilizes weekly NH 4+ concentrations in precipitation in conjunction with boundary layer air mass back trajectories, is developed to statistically test for the influence of a particular NH 3 source region on NH 4+ concentrations at surrounding NADP/NTN sites for the years 1995-1996. NH 3 emissions from this source region, primarily evolving from swine and poultry operations, are found to increase NH 4+ concentration in precipitation at sites up to ≈80 km away. At the Scotland County (NC36) and Wake County (NC41) sites, mean NH 4+ concentrations show increases of at least 44% for weeks during which 25% or more back trajectories are influenced by this source region.

  13. Effects of High Ammonium Concentration on Growth and Nutrient Uptake of Lettuce Plants with Solution Culture

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A nutrition solution experiment was conducted over two months to investigate the response of vegetable crops to high concentrations of ammonium, using lettuce (Lactuca sativa L. cv. Angustana Irish) as a test crop. Ammonium concentrations were designed in 5 levels, ranging from 12 mmol N L-1 to 22 mmol N L-1 and local tap water was used as water source. At the first culture stage (0-9 days), lettuce plants maintained normal growth while the lettuce roots were increasingly impaired. During the subsequent three stages the root structure was greatly damaged, and roots became brown or black through continuous supply of high concentration of ammonium. However, there was no obvious reduction of the aboveground biomass of the plants in the high ammonium treatments compared to those supplied with nitrate alone. In contrast to results obtained in another experiment from us with distilled water, the detrimental effect of high ammonium concentration on lettuce growth was greatly alleviated. Based on the results, it was postulated that the small amount of nitrate and the higher amount of bicarbonate existed in the tap water might mitigate the adverse effects of high ammonium N. The higher bicarbonate content in water and soil has usually been regarded as a major constraint factor limiting plant growth in calcareous soil areas. However, the reaction of bicarbonate to ammonium might produce positively interactive effect on reduction of both damages. The lettuce plants grown in ammonium solutions took up less P, K, Fe, Mn and Cu and more Ca than those grown in the nitrate nutrient solution. In conclusion, the results indicated that the N form imposed an obvious influence on absorption of cations and anions. Supplying ammonium-N stimulated transport of Ca, Mg and Mn to shoots of lettuce.

  14. Natural attenuation potential of tricholoroethene in wetland plant roots: role of native ammonium-oxidizing microorganisms.

    Science.gov (United States)

    Qin, Ke; Struckhoff, Garrett C; Agrawal, Abinash; Shelley, Michael L; Dong, Hailiang

    2015-01-01

    Bench-scale microcosms with wetland plant roots were investigated to characterize the microbial contributions to contaminant degradation of trichloroethene (TCE) with ammonium. The batch system microcosms consisted of a known mass of wetland plant roots in aerobic growth media where the roots provided both an inoculum of root-associated ammonium-oxidizing microorganisms and a microbial habitat. Aqueous growth media, ammonium, and TCE were replaced weekly in batch microcosms while retaining roots and root-associated biomass. Molecular biology results indicated that ammonium-oxidizing bacteria (AOB) were enriched from wetland plant roots while analysis of contaminant and oxygen concentrations showed that those microorganisms can degrade TCE by aerobic cometabolism. Cometabolism of TCE, at 29 and 46 μg L(-1), was sustainable over the course of 9 weeks, with 20-30 mg L(-1) ammonium-N. However, at 69 μg L(-1) of TCE, ammonium oxidation and TCE cometabolism were completely deactivated in two weeks. This indicated that between 46 and 69 μg L(-1) TCE with 30 mg L(-1) ammonium-N there is a threshold [TCE] below which sustainable cometabolism can be maintained with ammonium as the primary substrate. However, cometabolism-induced microbial deactivation of ammonium oxidation and TCE degradation at 69 μg L(-1) TCE did not result in a lower abundance of the amoA gene in the microcosms, suggesting that the capacity to recover from TCE inhibition was still intact, given time and removal of stress. Our study indicates that microorganisms associated with wetland plant roots can assist in the natural attenuation of TCE in contaminated aquatic environments, such as urban or treatment wetlands, and wetlands impacted by industrial solvents.

  15. Syntheses and luminescence properties of two novel lanthanide (III) perchlorate complexes with phenacyl p-tolyl sulfoxide

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Shu-Yan [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China); Li, Wen-Xian, E-mail: nmglwx@163.com [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China); Zheng, Yu-Shan [Inner Mongolia Autonomous Region Product Quality Inspection Institute, Hohhot 010070 (China); Xin, Xiao-Dong; Guo, Feng; Cao, Xiao-Fang [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China)

    2015-06-15

    Two novel solid binary complexes of rare earth perchlorate with phenacyl p-tolyl sulfoxide were synthesized and characterized by elemental analysis, molar conductivity, coordination titration analysis, IR, TG-DSC, {sup 1}HNMR and UV spectra. The results indicated that the composition of these complexes was REL{sub 7} (ClO{sub 4}){sub 3}·6H{sub 2}O (RE=Eu (III), Tb (III), L=C{sub 6}H{sub 5}COCH{sub 2}SOC{sub 6}H{sub 4}CH{sub 3}). The study on IR spectra and {sup 1}HNMR spectra revealed that phenacyl p-tolyl sulfoxide bonded with RE{sup 3+} ions by the oxygen atom in sulfinyl group. The emission spectra illustrated that both the Eu (III) and Tb (III) complexes displayed excellent luminescence in solid state, and The most intensive characteristic emission of the Eu(III) and Tb(III) complexes were 245,400 a.u. and 298,000 a.u. respectively. The slit with was 1 nm. By analysis luminescence and phosphorescence spectrum, it was found that the ligand had the advantage to absorb energy and transfer it to the Eu (III) and Tb (III) ions. The fluorescence lifetimes of the complexes were measured as well as the quantum yield of the Eu (III) complex.

  16. The angiogenic effect of dracorhodin perchlorate on human umbilical vein endothelial cells and its potential mechanism of action.

    Science.gov (United States)

    Li, Feng; Jiang, Tao; Liu, Wei; Hu, Quan; Yin, Huinan

    2016-08-01

    Hyperglycemia is the key clinical feature of diabetes, and may induce refractory wound lesions and impaired angiogenesis. Dracorhodin perchlorate (Dra) is the major ingredient of dragon's blood and it has been used as a medicine to treat chronic wounds, such as diabetic foot, since ancient times in many cultures. The current study aimed to investigate the effect of Dra on human umbilical vein endothelial cells (HUVECs) under high‑glucose (HG) stimulation and its potential mechanism. Dra was observed to increase the multiplication capacity of HUVECs both under low glucose (LG) and HG concentrations. Additionally, migration and tube formation in HUVECs was facilitated by Dra. The expression levels of Ras, mitogen‑activated protein kinase (MAPK) and vascular endothelial growth factor, which are key components of the Ras/MAPK pathway, were upregulated following Dra treatment. The present study is the first report, to the best of our knowledge, of the effects of Dra on wound healing, and the association with the Ras/MAPK signaling pathway. PMID:27357516

  17. Syntheses and luminescence properties of two novel lanthanide (III) perchlorate complexes with phenacyl p-tolyl sulfoxide

    International Nuclear Information System (INIS)

    Two novel solid binary complexes of rare earth perchlorate with phenacyl p-tolyl sulfoxide were synthesized and characterized by elemental analysis, molar conductivity, coordination titration analysis, IR, TG-DSC, 1HNMR and UV spectra. The results indicated that the composition of these complexes was REL7 (ClO4)3·6H2O (RE=Eu (III), Tb (III), L=C6H5COCH2SOC6H4CH3). The study on IR spectra and 1HNMR spectra revealed that phenacyl p-tolyl sulfoxide bonded with RE3+ ions by the oxygen atom in sulfinyl group. The emission spectra illustrated that both the Eu (III) and Tb (III) complexes displayed excellent luminescence in solid state, and The most intensive characteristic emission of the Eu(III) and Tb(III) complexes were 245,400 a.u. and 298,000 a.u. respectively. The slit with was 1 nm. By analysis luminescence and phosphorescence spectrum, it was found that the ligand had the advantage to absorb energy and transfer it to the Eu (III) and Tb (III) ions. The fluorescence lifetimes of the complexes were measured as well as the quantum yield of the Eu (III) complex

  18. Synthesis and Crystal Structure of the Perchlorate Salt of Diprotonated 2,3-Di-2-pyridyl-5-nitroquinoxaline

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The diprotonated perchlorate salt of 2,3-di-2-pyridyl-5-nitroquinoxaline [C18H13N5O2](ClO4)2((CH3OH)((C2H5OH) has been synthesized and characterized by elemental analysis, IR and NMR spectra. X-ray diffraction analysis at room temperature indicates that the title compound (C21H23N5O12Cl2, Mr = 608.34) crystallizes in triclinic, space group P ī with a = 7.992(8), b = 12.82(1), c = 13.42(1) (A), α= 104.77(2), β = 97.84(2), γ = 95.48(2), V = 1305(2) (A)3, Z = 2, Dc = 1.549 g/cm3, F(000) = 628 and ((MoK() = 0.317 mm-1. The final R and wR factors are 0.0566 and 0.1016, respectively with 4325 independent reflections. The quinoxaline ring makes the dihedral angles of 44.2(2) and 33.9(5)( with two protonated pyridine rings whose dihedral angle is 48.1(6)(. The favored orientation of two protonated pyridine rings is that their N atoms are opposite to each other. There exist intra- and inter-molecular N-H…O hydrogen bonds and π…π interactions which stabilize the structure further.

  19. Noncovalent Complexation of Monoamine Neurotransmitters and Related Ammonium Ions by Tetramethoxy Tetraglucosylcalix[4]arene

    Science.gov (United States)

    Torvinen, Mika; Kalenius, Elina; Sansone, Francesco; Casnati, Alessandro; Jänis, Janne

    2012-02-01

    The noncovalent complexation of monoamine neurotransmitters and related ammonium and quaternary ammonium ions by a conformationally flexible tetramethoxy glucosylcalix[4]arene was studied by electrospray ionization Fourier transform ion cyclotron resonance (ESI-FTICR) mass spectrometry. The glucosylcalixarene exhibited highest binding affinity towards serotonin, norepinephrine, epinephrine, and dopamine. Structural properties of the guests, such as the number, location, and type of hydrogen bonding groups, length of the alkyl spacer between the ammonium head-group and the aromatic ring structure, and the degree of nitrogen substitution affected the complexation. Competition experiments and guest-exchange reactions indicated that the hydroxyl groups of guests participate in intermolecular hydrogen bonding with the glucocalixarene.

  20. Rotational barriers in ammonium hexachlorometallates as studied by NMR, tunneling spectroscopy and ab initio calculations

    DEFF Research Database (Denmark)

    Birczynski, A.; Lalowicz, Z.T.; Lodziana, Zbigniew

    2004-01-01

    Ammonium hexachlorometallates, (NH4)(2)MCl6 With M = Pd, Pt, Ir, Os, Re, Se, Sn, Te and Pb, comprise a set of compounds with systematically changing properties. The compounds may be ordered according to decreasing tunnelling frequency (TF) of ammonium ions, which is related to the increasing...... structure explain observed variation of the tunnelling frequencies for NH4+. The theory provides also M-Cl distances and barriers for C-2 and C-3 rotations of ammonium ions in respective compounds, which show good agreement with experimental values. (C) 2004 Elsevier B.V. All rights reserved....