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Sample records for aminobenzene

  1. Electrochemical characterization of mixed self-assembled films of water-soluble single-walled carbon nanotube-poly(m-aminobenzene sulfonic acid) and Iron(II) tetrasulfophthalocyanine

    CSIR Research Space (South Africa)

    Agboola, BO

    2010-09-01

    Full Text Available The redox activities of water-soluble iron(II) tetrasulfophthalocyanine (FeTSPc) and single-walled carbon nanotube-poly(m-aminobenzene sulfonic acid) (SWCNT-PABS) adsorbed on a gold surface precoated with a self-assembled monolayer (SAM) of 2...

  2. Sensitive electrochemical determination of trace cadmium on a stannum film/poly(p-aminobenzene sulfonic acid)/electrochemically reduced graphene composite modified electrode

    International Nuclear Information System (INIS)

    Wang, Zhiqiang; Wang, Hui; Zhang, Zhihao; Yang, Xiaojing; Liu, Gang

    2014-01-01

    In this study, a novel stannum film/poly(p-aminobenzene sulfonic acid)/graphene composite modified glassy carbon electrode (GCE) was prepared by using electrodeposition of exfoliated graphene oxide, electropolymerization of p-aminobenzene sulfonic acid (p-ABSA) and in situ plating stannum fim methods, successively. This sensor was further used for sensitive determination of trace cadmium ions by square wave anodic stripping voltammetry (SWASV). The morphologies and electrochemistry properties of the modified electrode were characterized by scanning electron microscopy, Raman spectroscopy, cyclic voltammetry, electrochemical impedance spectroscopy and linear sweep voltammetry. It was found that the formed graphene layer on the top of GCE could remarkably facilitate the electron transfer and enlarge the specific surface area of the electrode. While the poly(p-ABSA) film could effectively increase the adhesion and stability of graphene layer, enhance ion-exchange capacity and prevent the macromolecule in real samples absorbing on the surface of electrode. By combining co-deposits ability with heavy metals of stannum film, the obtained electrode exhibited a good stripping performance for the analysis of Cd(II). Under the optimum conditions, a linear response was observed in the range from 1.0 to 70.0 μgL −1 with a detection limit of 0.05 μgL −1 (S/N = 3). The sensor was further applied to the determination of cadmium ions in real water samples with satisfactory results

  3. Electrochemistry of 2-dimethylaminoethanethiol SAM on gold electrode: Interaction with SWCNT-poly(m-aminobenzene sulphonic acid), electric field-induced protonation-deprotonation, and surface pKa

    CSIR Research Space (South Africa)

    Pillay, J

    2009-06-01

    Full Text Available Electrochemical behaviour of self-assembled monolayer of 2-dimethylaminoethanethiol (DMAET) on gold electrode, with and without integration with SWCNT-poly(m-aminobenzene sulphonic acid) (SWCNT-PABS) has been probed. It is proved that the so...

  4. Effect of the intercalated cation-exchanged on the properties of nanocomposites prepared by 2-aminobenzene sulfonic acid with aniline and montmorillonite

    Energy Technology Data Exchange (ETDEWEB)

    Toumi, I. [Laboratoire de Chimie Organique, Macromoleculaire et des Materiaux, Universite de Mascara, Bp 763 Mascara 29000 (Algeria); Benyoucef, A., E-mail: ghani29000@yahoo.fr [Laboratoire de Chimie Organique, Macromoleculaire et des Materiaux, Universite de Mascara, Bp 763 Mascara 29000 (Algeria); Yahiaoui, A. [Laboratoire de Chimie Organique, Macromoleculaire et des Materiaux, Universite de Mascara, Bp 763 Mascara 29000 (Algeria); Quijada, C. [Departamento de Ingenieria Textil y Papelera, Universidad Politecnica de Valencia, Pza Ferrandiz i Carbonel, E-03801 Alcoy, Alicante (Spain); Morallon, E. [Departamento de Quimica Fisica e Instituto Universitario de Materiales, Universidad de Alicante, Apartado 99, E-03080 Alicante (Spain)

    2013-02-25

    Polymer/montmorillonite nanocomposites were prepared. Intercalation of 2-aminobenzene sulfonic acid with aniline monomers into montmorillonite modified by cation was followed by subsequent oxidative polymerization of monomers in the interlayer spacing. The clay was prepared by cation exchange process between sodium cation in (M-Na) and copper cation (M-Cu). XRD analyses show the manifestation of a basal spacing (d-spacing) for M-Cu changes depending on the inorganic cation and the polymer intercalated in the M-Cu structure. TGA analyses reveal that polymer/M-Cu composites is less stable than M-Cu. The conductivity of the composites is found to be 10{sup 3} times higher than that for M-Cu. The microscopic examinations including TEM picture of the nanocomposite demonstrated an entirely different and more compatible morphology. Remarkable differences in the properties of the polymers have also been observed by UV-Vis and FTIR, suggesting that the polymer produced with presence of aniline has a higher degree of branching. The electrochemical behavior of the polymers extracted from the nanocomposites has been studied by cyclic voltammetry which indicates the electroactive effect of nanocomposite gradually increased with aniline in the polymer chain.

  5. THE CASE FOR THE CONTRIBUTION OF CRISTAIS RIVER NITRO-AMINOBENZENE DYES TO THE MUTAGENICITY OF AMBIENT SAMPLES

    Science.gov (United States)

    In order to verify if dyestuffs within an effluent of a textile industry was contributing to the systematic mutagenicity detected in the Cristais River, within the metropolitan region of Sao Paulo, mutagenic samples of the industrial effluent, crude water, and treated silt of the...

  6. An Environmentally Friendly Solvent-free Synthesis of 3,4 ...

    African Journals Online (AJOL)

    NICO

    An Environmentally Friendly Solvent-free Synthesis of. 3,4-Dihydropyrimidinones using a p-Aminobenzene. Sulfonic Acid Catalyzed Biginelli Reaction. Ming Shu Wu,a,b,* Ping Heb and Xiang Zhu Zhanga. aDepartment of Chemical Engineering, Institute of Anyang Technology, Anyang, 455000, Henan, P.R. China.

  7. An Environmentally Friendly Solvent-free Synthesis of 3,4 ...

    African Journals Online (AJOL)

    Anhydrous p-aminobenzene sulphonic acid mediated solvent-free protocol is described for the synthesis of dihydropyrimidinones by the cyclocondensation of aldehydes, β-ketoesters and urea/thiourea. Yields obtained are significantly higher than those obtained utilizing classical Biginelli reaction conditions. Keywords: ...

  8. Untitled

    Indian Academy of Sciences (India)

    -aminobenzene-camphor:#"P”. AM SAAAAASA SAASAASSMMSSSLgAAA AAAA AAAASASASS. 一口. Solvent Water Methyl alcohol Ethyl alcohol } Pyridine. Concentration ( d- 1-0000 1.0000 1.0000 in gms./100 c.c. i - I • 0000 | 1 .0000 1.0000 ...

  9. Colloidal polyaniline

    Science.gov (United States)

    Armes, Steven P.; Aldissi, Mahmoud

    1990-01-01

    Processable electrically conductive latex polymer compositions including colloidal particles of an oxidized, polymerized amino-substituted aromatic monomer, a stabilizing effective amount of a random copolymer containing amino-benzene type moieties as side chain constituents, and dopant anions, and a method of preparing such polymer compositions are provided.

  10. Activation analysis of trace amounts of rare earth in high purity tantalum

    International Nuclear Information System (INIS)

    Ishibashi, Wataru; Saito, Shinichi; Hirayama, Tooru.

    1975-01-01

    It is necessary to separate rare earth from tantalum by rapid methods in order to remove effects of a strong radioactivity and a short half-life. Tantalum is extracted with 10%N-lauryl (trialkylmethyl) amino-benzene pre-equilibrated with a solution of 9 M hydrochloric and 0.15 M hydrofluoric acid. A non-radioactive rare earth element is added to this aqueous solution, a precipitate of trace amounts of radioactive rare earth in aqueous solution is formed by this addition of rare earth. Some factors in the determination are: 1) the effect of the irradiation position of the sample in the atomic reactor, 2) the effect on the extraction with 10%N-lauryl (trialkylmethyl) amino-benzene for the radioactive rare earth, 3) the effect of the concentration of hydrofluoric acid, ammonia water and nitric acid on co-precipitation. As a result of the investigation we obtained the following satisfactory results: 1) Rare earth was not effected by the extraction of tantalum with 10%N-lauryl (trialkylmethyl) amino-benzene. 2) The recovery of rare earth by co-precipitation increases when an ammonium ion coexists, and when the concentration of hydrofluoric acid decreases, but the recovery decreases with the increase of nitric acid concentration. 3) The time required for the extraction is 9 hours. In case of determination for dysprosium, tantalum extracted with 10%N-lauryl (trialkylmethyl) amino-benzene before activation and the time for separation is 2 hours. (auth.)

  11. Improved Method for the Synthesis of New 1,5-Benzothiazepine Derivatives as Analogues of Anticancer Drugs

    Directory of Open Access Journals (Sweden)

    L. Prakash

    1997-09-01

    Full Text Available (±cis-2-(4-Methoxyphenyl-3-hydroxy/methoxy-2,3-dihydro-1,5-benzothiazepin-4[5H/5-chloroacetyl/5-(4'-methylpiperazino-1'acetyl]-ones have been synthesized by the condensation of 2-aminobenzene thiols with methyl(±trans-3-(4-methoxyphenylglycidate in xylene. The synthesized compounds have been characterized by elemental analyses and spectral data and screened for their antimicrobial activity.

  12. Strategically functionalized carbon nanotubes as the ultrasensitive electrochemical probe for picomolar detection of sildenafil citrate (Viagra).

    Science.gov (United States)

    Gopalan, Anantha Iyengar; Lee, Kwang Pill; Komathi, Shanmugasundaram

    2011-02-15

    The present work demonstrates the utility of the functionalized carbon nanotubes, poly(4-aminobenzene sulfonic acid) (PABS) grafted multiwalled carbon nanotubes, MWNT-g-PABS, as an electrode modifier towards achieving ultrasensitive detection of a model drug, sildenafil citrate (SC). PABS units in MWNT-g-PABS interact with SC, pre-concentrate and accumulate at the surface. The electron transduction from SC to electrode is augmented via MWNT-g-PABS. As a result, the MWNT-g-PABS modified electrode exhibited ultrasensitive (57.7 μA/nM) and selective detection of SC with a detection limit of 4.7 pM. The present work provides scope towards targeting ultrasensitivity for the detection of biomolecules/drug through rational design and incorporation of appropriate chemical components to carbon nanotubes. Copyright © 2010 Elsevier B.V. All rights reserved.

  13. Heat capacities of aqueous polar aromatic compounds over a wide range of conditions. Part I: phenol, cresols, aniline, and toluidines

    International Nuclear Information System (INIS)

    Censky, Miroslav; Hnedkovsky, Lubomir; Majer, Vladimir

    2005-01-01

    The heat capacities of dilute aqueous solutions of phenol (hydroxybenzene), three cresols (2-, 3- and 4-methylhydroxybenzene), aniline (aminobenzene) and three toluidines (2-, 3- and 4-methylaminobenzene) were determined using a modified flow Picker-type high temperature calorimeter. The measurements were performed at temperatures between (303 and 623) K or 573 K for compounds containing hydroxy or amino group, respectively, and at several pressures up to 30 MPa. Standard heat capacities (partial molar heat capacities at infinite dilution) obtained from the experimental data exhibit a strong increase with temperature above 500 K consistent with the evolution of the standard volumes reported earlier. The data for aqueous phenol were used for testing several semiempiric models proposed for description of the standard thermodynamic properties of aqueous solutes. Their ability to reproduce the temperature and pressure dependence of standard heat capacities and to extrapolate towards higher conditions were examined

  14. Synthesis of fully and partially sulfonated polyanilines derived from ortanilic acid: An electrochemical and electromicrogravimetric study

    International Nuclear Information System (INIS)

    Cano Marquez, Abraham Guadalupe; Torres Rodriguez, Luz Maria; Montes Rojas, Antonio

    2007-01-01

    The electrochemical polymerization of 2-aminobenzene sulfonic acid, also called ortanilic acid (o-ASA), on a gold electrode precoated with polyaniline (PANI), has been carried out. We proved that the electropolymerization of o-ASA is enhanced on PANI electrodes, resulting in thicker films obtained in aqueous media at room temperature. The electrosynthesized film (P(o-ASA)) was characterized by cyclic voltammetry, FTIR and nuclear magnetic resonance. The compensation of P(o-ASA) charge was evaluated using electrochemical quartz crystal microbalance combined with cyclic voltammetry, which showed that the electroneutralization process mainly involves cations. Additionally, copolymers of aniline and o-ASA were electrosynthesized, using a metallic electrode modified with PANI also as a working electrode. The degree of sulfanation of copolymers has been modulated with the proportions of monomers in the electrosynthesis solution. The studies reveal a more important participation of cations in fully sulfonated polyaniline than in partially sulfonated polyaniline

  15. Solvent-switchable continuous-breathing behaviour in a diamondoid metal-organic framework and its influence on CO2 versus CH4 selectivity

    Science.gov (United States)

    Carrington, Elliot J.; McAnally, Craig A.; Fletcher, Ashleigh J.; Thompson, Stephen P.; Warren, Mark; Brammer, Lee

    2017-09-01

    Understanding the behaviour of flexible metal-organic frameworks (MOFs)—porous crystalline materials that undergo a structural change upon exposure to an external stimulus—underpins their design as responsive materials for specific applications, such as gas separation, molecular sensing, catalysis and drug delivery. Reversible transformations of a MOF between open- and closed-pore forms—a behaviour known as 'breathing'—typically occur through well-defined crystallographic transitions. By contrast, continuous breathing is rare, and detailed characterization has remained very limited. Here we report a continuous-breathing mechanism that was studied by single-crystal diffraction in a MOF with a diamondoid network, (Me2NH2)[In(ABDC)2] (ABDC, 2-aminobenzene-1,4-dicarboxylate). Desolvation of the MOF in two different solvents leads to two polymorphic activated forms with very different pore openings, markedly different gas-adsorption capacities and different CO2 versus CH4 selectivities. Partial desolvation introduces a gating pressure associated with CO2 adsorption, which shows that the framework can also undergo a combination of stepped and continuous breathing.

  16. Crystal and molecular structure of 3-methyl-4-(2,4,6-triphenylpyridinium-1-yl)-phenolate salts with o-arsanilic and perchloric acids

    Science.gov (United States)

    Wojtas, Łukasz; Milart, Piotr; Stadnicka, Katarzyna

    2006-01-01

    The crystal structure for two salts of 3-methyl-4-(2,4,6-triphenylpyridinium-1-yl)-phenolate ( 1) with o-arsanilic (2-aminobenzene-arsonic) and perchloric acids were determined by X-ray diffraction. 1 was synthesized in order to break the symmetry of 4-(2,4,6-triphenylpyridinium-1-yl)-phenolate ( 2) and to overcome a tendency of the molecule for centrosymmetrical arrangement in a crystalline state. The structure of 1·HClO 4 (space group Pbca) is governed by an antiparallel arrangement of pyridinium cations, connected to perchlorate anions through hydrogen bonds of O-H⋯O type. The crystals of 1·H 2NC 6H 4AsO 3H 2·H 2O belong to tetragonal space group I4¯. Due to strong O-H⋯O - and moderate N-H⋯O - interactions, hydrogen o-arsaniliate counterions form aggregates to which the cations of 1 are connected via O-H⋯O dbnd6 As hydrogen bonds. The anionic aggregates are linked together by the crystallization water molecules through the system of hydrogen bonds. The comparison of the 1-(4-hydroxy-2-methylphenyl)-2,4,6-triphenylpyridinium hydrogen o-arsanilate and perchlorate structures reveals the importance of choosing the appropriate acids in order to obtain desired structure properties.

  17. Biodecolorization of a food azo dye by the deep sea Dermacoccus abyssi MT1.1(T) strain from the Mariana Trench.

    Science.gov (United States)

    Lang, Weeranuch; Sirisansaneeyakul, Sarote; Martins, Lígia O; Ngiwsara, Lukana; Sakairi, Nobuo; Pathom-aree, Wasu; Okuyama, Masayuki; Mori, Haruhide; Kimura, Atsuo

    2014-01-01

    This study reports the characterization of the ability of Dermacoccus spp. isolated from the deepest point of the world's oceans for azo dye decolorization. A detailed investigation of Dermacoccus abyssi MT1.1(T) with respect to the azoreductase activity and enzymatic mechanism as well as the potential role of the bacterial strain for biocleaning of industrial dye baths is reported. Resting cells with oxygen-insensitive azoreductase resulted in the rapid decolorization of the polysulfonated dye Brilliant Black BN (BBN) which is a common food colorant. The highest specific decolorization rate (vs) was found at 50 °C with a moderately thermal tolerance for over 1 h. Kinetic analysis showed the high rates and strong affinity of the enzymatic system for the dye with a Vmax = 137 mg/g cell/h and a Km = 19 mg/L. The degradation of BBN produces an initial orange intermediate, 8-amino-5-((4-sulfonatophenyl)diazenyl)naphthalene-2-sulfonic acid, identified by mass spectrometry which is later converted to 4-aminobenzene sulfonic acid. Nearly 80% of the maximum vs is possible achieved in resting cell treatment with the salinity increased up to 5.0% NaCl in reaction media. Therefore, this bacterial system has potential for dye decolorization bioprocesses occurring at high temperature and salt concentrations e.g. for cleaning dye-containing saline wastewaters. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. 3-Amino-1-(3,4-dimethoxyphenyl-9,10-dihydrophenanthrene-2,4-dicarbonitrile

    Directory of Open Access Journals (Sweden)

    Abdullah M. Asiri

    2012-04-01

    Full Text Available In the title compound, C24H19N3O2, the partially saturated ring adopts a distorted half-chair conformation with the methylene-C atom closest to the aminobenzene ring lying 0.664 (3 Å out of the plane defined by the five remaining atoms (r.m.s. deviation = 0.1429 Å. The dihedral angle [32.01 (10°] between the benzene rings on either side of this ring indicates a significant fold in this part of the molecule. The dimethoxy-substituted benzene ring is almost orthogonal to the benzene ring to which it is attached [dihedral angle = 72.03 (9°]. The molecule has been observed previously as the major component of a 1:19 co-crystal with 2-amino-4-(3,4-dimethoxyphenyl-5,6-dihydrobenzo[ha]quinoline-3-carbonitrile [Asiri et al. (2011. Acta Cryst. E67, o2873–o2873]. Supramolecular chains with base vector [201] are formed in the crystal structure via N—H...O hydrogen bonds between the amino H atoms of one molecule interacting with the methoxy O atoms of a neighbouring molecule. The chains are linked into a three-dimensional architecture by C—H...π interactions.

  19. [Determination of the daily changes curve of nitrogen oxides in the atmosphere by digital imaging colorimetry method].

    Science.gov (United States)

    Yang, Chuan-Xiao; Sun, Xiang-Ying; Liu, Bin

    2009-06-01

    From the digital images of the red complex which resulted in the interaction of nitrite with N-(1-naphthyl) ethylenediamine dihydrochloride and P-Aminobenzene sulfonic acid, it could be seen that the solution colors obviously increased with increasing the concentration of nitrite ion. The JPEG format of the digital images was transformed into gray-scale format by origin 7.0 software, and the gray values were measured with scion image software. It could be seen that the gray values of the digital image obviously increased with increasing the concentration of nitrite ion, too. Thus a novel digital imaging colorimetric (DIC) method to determine nitrogen oxides (NO(x)) contents in air was developed. Based on the red, green and blue (RGB) tricolor theory, the principle of the digital imaging colorimetric method and the influential factors on digital imaging were discussed. The present method was successfully applied to the determination of the daily changes curve of nitrogen oxides in the atmosphere and NO2- in synthetic samples with the recovery of 97.3%-104.0%, and the relative standard deviation (RSD) was less than 5.0%. The results of the determination were consistent with those obtained by spectrophotometric method.

  20. Three-dimensional activated graphene network-sulfonate-terminated polymer nanocomposite as a new electrode material for the sensitive determination of dopamine and heavy metal ions.

    Science.gov (United States)

    Yuan, Xiaoyan; Zhang, Yijia; Yang, Lu; Deng, Wenfang; Tan, Yueming; Ma, Ming; Xie, Qingji

    2015-03-07

    We report here that three-dimensional activated graphene networks (3DAGNs) are a better matrix to prepare graphene-polymer nanocomposites for sensitive electroanalysis than two-dimensional graphene nanosheets (2DGNs). 3DAGNs were synthesized in advance by the direct carbonization and simultaneous chemical activation of a cobalt ion-impregnated D113-type ion exchange resin, which showed an interconnected network structure and a large specific surface area. Then, the 3DAGN-sulfonate-terminated polymer (STP) nanocomposite was prepared via the in situ chemical co-polymerization of m-aminobenzene sulfonic acid and aniline in the presence of 3DAGNs. The 3DAGN-STP nanocomposite can adsorb dopamine (DA) and heavy metal ions, which was confirmed by quartz crystal microbalance studies. The 3DAGN-STP modified glassy carbon electrode (GCE) was used for the electrochemical detection of DA in the presence of ascorbic acid and uric acid, with a linear response range of 0.1-32 μM and a limit of detection of 10 nM. In addition, differential pulse voltammetry was used for the simultaneous determination of Cd(2+) and Pb(2+) at the 3DAGN-STP/GCE further modified with a bismuth film, exhibiting linear response ranges of 1-70 μg L(-1) for Cd(2+) and 1-80 μg L(-1) for Pb(2+) with limits of detection of 0.1 μg L(-1) for Cd(2+) and 0.2 μg L(-1) for Pb(2+). Because the 3DAGN-STP can integrate the advantages of 3DAGNs with STPs, the 3DAGN-STP/GCE was more sensitive than the bare GCE, 3DAGN/GCE, and 2DGN-STP/GCE for the determination of DA and heavy metal ions.

  1. Synthesis, spectroscopic and TD-DFT quantum mechanical study of azo-azomethine dyes. A laser induced trans-cis-trans photoisomerization cycle

    Science.gov (United States)

    Georgiev, Anton; Kostadinov, Anton; Ivanov, Deyan; Dimov, Deyan; Stoyanov, Simeon; Nedelchev, Lian; Nazarova, Dimana; Yancheva, Denitsa

    2018-03-01

    This paper describes the synthesis, spectroscopic characterization and quantum mechanical calculations of three azo-azomethine dyes. The dyes were synthesized via condensation reaction between 4-(dimethylamino)benzaldehyde and three different 4-aminobenzene azo dyes. Quantum chemical calculations on the optimized molecular geometry and electron densities of the trans (E) and cis (Z) isomers and their vibrational frequencies have been computed by using DFT/B3LYP density-functional theory with 6-311 ++G(d,p) basis set in vacuo. The thermodynamic parameters such as total electronic energy E (RB3LYP), enthalpy H298 (sum of electronic and thermal enthalpies), free Gibbs energy G298 (sum of electronic and thermal free Gibbs energies) and dipole moment μ were computed for trans (E) and cis (Z) isomers in order to estimate the ΔEtrans → cis, Δμtrans → cis,ΔHtrans → cis, ΔGtrans → cis and ΔStrans → cis values. After molecular geometry optimization the electronic spectra have been obtained by TD-DFT calculations at same basis set and correlated with the spectra of vapour deposited nanosized films of the dyes. The NBO analysis was performed in order to understand the intramolecular charge transfer and energy of resonance stabilization. Solvatochromism was investigated by UV-VIS spectroscopy in five different organic solvents with increasing polarity. The dynamic photoisomerization experiments have been performed in DMF by pump lasers λ = 355 nm (mostly E → Z) and λ = 491 nm (mostly Z → E) in spectral region 300 nm - 800 nm at equal concentrations and times of illumination in order to investigate the photodynamical trans-cis-trans properties of the sbnd CHdbnd Nsbnd and sbnd Ndbnd Nsbnd chromophore groups of the dyes.

  2. Degradation Network Reconstruction in Uric Acid and Ammonium Amendments in Oil-Degrading Marine Microcosms Guided by Metagenomic Data

    KAUST Repository

    Bargiela, Rafael

    2015-11-24

    Biostimulation with different nitrogen sources is often regarded as a strategy of choice in combating oil spills in marine environments. Such environments are typically depleted in nitrogen, therefore limiting the balanced microbial utilization of carbon-rich petroleum constituents. It is fundamental, yet only scarcely accounted for, to analyze the catabolic consequences of application of biostimulants. Here, we examined such alterations in enrichment microcosms using sediments from chronically crude oil-contaminated marine sediment at Ancona harbor (Italy) amended with natural fertilizer, uric acid (UA), or ammonium (AMM). We applied the web-based AromaDeg resource using as query Illumina HiSeq meta-sequences (UA: 27,893 open reading frames; AMM: 32,180) to identify potential catabolic differences. A total of 45 (for UA) and 65 (AMM) gene sequences encoding key catabolic enzymes matched AromaDeg, and their participation in aromatic degradation reactions could be unambiguously suggested. Genomic signatures for the degradation of aromatics such as 2-chlorobenzoate, indole-3-acetate, biphenyl, gentisate, quinoline and phenanthrene were common for both microcosms. However, those for the degradation of orcinol, ibuprofen, phenylpropionate, homoprotocatechuate and benzene (in UA) and 4-aminobenzene-sulfonate, p-cumate, dibenzofuran and phthalate (in AMM), were selectively enriched. Experimental validation was conducted and good agreement with predictions was observed. This suggests certain discrepancies in action of these biostimulants on the genomic content of the initial microbial community for the catabolism of petroleum constituents or aromatics pollutants. In both cases, the emerging microbial communities were phylogenetically highly similar and were composed by very same proteobacterial families. However, examination of taxonomic assignments further revealed different catabolic pathway organization at the organismal level, which should be considered for designing

  3. Modeling Bimolecular Reactions and Transport in Porous Media Via Particle Tracking

    Energy Technology Data Exchange (ETDEWEB)

    Dong Ding; David Benson; Amir Paster; Diogo Bolster

    2012-01-01

    We use a particle-tracking method to simulate several one-dimensional bimolecular reactive transport experiments. In this numerical method, the reactants are represented by particles: advection and dispersion dominate the flow, and molecular diffusion dictates, in large part, the reactions. The particle/particle reactions are determined by a combination of two probabilities dictated by the physics of transport and energetics of reaction. The first is that reactant particles occupy the same volume over a short time interval. The second is the conditional probability that two collocated particles favorably transform into a reaction. The first probability is a direct physical representation of the degree of mixing in an advancing displacement front, and as such lacks empirical parameters except for the user-defined number of particles. This number can be determined analytically from concentration autocovariance, if this type of data is available. The simulations compare favorably to two physical experiments. In one, the concentration of product, 1,2-naphthoquinoe-4-aminobenzene (NQAB) from reaction between 1,2-naphthoquinone-4-sulfonic acid (NQS) and aniline (AN), was measured at the outflow of a column filled with glass beads at different times. In the other, the concentration distribution of reactants (CuSO_4 and EDTA^{4-}) and products (CuEDTA^{4-}) were quantified by snapshots of transmitted light through a column packed with cryloite sand. The thermodynamic rate coefficient in the latter experiment was 10^7 times greater than the former experiment, making it essentially instantaneous. When compared to the solution of the advection-dispersion-reaction equation (ADRE) with the well-mixed reaction coefficient, the experiments and the particle-tracking simulations showed on the order of 20% to 40% less overall product, which is attributed to poor mixing. The poor mixing also leads to higher product concentrations on the edges of the mixing zones, which the particle

  4. Degradation network reconstruction in uric acid and ammonium amendments in oil-degrading marine microcosms guided by metagenomic data

    Directory of Open Access Journals (Sweden)

    Rafael eBargiela

    2015-11-01

    Full Text Available Biostimulation with different nitrogen sources is often regarded as a strategy of choice in combating oil spills in marine environments. Such environments are typically depleted in nitrogen, therefore limiting the balanced microbial utilization of carbon-rich petroleum constituents. It is fundamental, yet only scarcely accounted for, to analyse the catabolic consequences of application of biostimulants. Here, we examined such alterations in enrichment microcosms using sediments from chronically crude oil-contaminated marine sediment at Ancona harbor (Italy amended with natural fertilizer, uric acid (UA, or ammonium (AMM. We applied the web-based AromaDeg resource using as query Illumina HiSeq meta-sequences (UA: 27,893 open reading frames; AMM: 32,180 to identify potential catabolic differences. A total of 45 (for UA and 65 (AMM gene sequences encoding key catabolic enzymes matched AromaDeg, and their participation in aromatic degradation reactions could be unambiguously suggested. Genomic signatures for the degradation of aromatics such as 2-chlorobenzoate, indole-3-acetate, biphenyl, gentisate, quinoline and phenanthrene were common for both microcosms. However, those for the degradation of orcinol, ibuprofen, phenylpropionate, homoprotocatechuate and benzene (in UA and 4-aminobenzene-sulfonate, p-cumate, dibenzofuran and phthalate (in AMM, were selectively enriched. Experimental validation was conducted and good agreement with predictions was observed. This suggests certain discrepancies in action of these biostimulants on the genomic content of the initial microbial community for the catabolism of petroleum constituents or aromatics pollutants. In both cases, the emerging microbial communities were phylogenetically highly similar and were composed by very same proteobacterial families. However, examination of taxonomic assignments further revealed different catabolic pathway organization at the organismal level, which should be considered