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Sample records for additional ozone production

  1. Southern Hemisphere Additional Ozonesondes (SHADOZ) Ozone Climatology (2005-2009): Tropospheric and Tropical Tropopause Layer (TTL) Profiles with Comparisons to Omi-based Ozone Products

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Miller, Sonya K.; Tilmes, Simone; Kollonige, Debra W.; Witte, Jacquelyn C.; Oltmans, Samuel J.; Johnson, Brian J.; Fujiwara, Masatomo; Schmidlin, F. J.; Coetzee, G. J. R.; Komala, Ninong; Maata, Matakite; bt Mohammad, Maznorizan; Nguyo, J.; Mutai, C.; Ogino, S-Y; Da Silva, F. Raimundo; Paes Leme, N. M.; Posny, Francoise; Scheele, Rinus; Selkirk, Henry B.; Shiotani, Masato; Stubi, Rene; Levrat, Gilbert; Calpini, Bertrand; Thouret, Valerie; Tsuruta, Haruo; Canossa, Jessica Valverde; Voemel, Holger; Yonemura, S.; Andres Diaz, Jorge; Tan Thanh, Nguyen T.; Thuy Ha, Hoang T.

    2012-01-01

    We present a regional and seasonal climatology of SHADOZ ozone profiles in the troposphere and tropical tropopause layer (TTL) based on measurements taken during the first five years of Aura, 2005-2009, when new stations joined the network at Hanoi, Vietnam; Hilo, Hawaii; Alajuela Heredia, Costa Rica; Cotonou, Benin. In all, 15 stations operated during that period. A west-to-east progression of decreasing convective influence and increasing pollution leads to distinct tropospheric ozone profiles in three regions: (1) western Pacific eastern Indian Ocean; (2) equatorial Americas (San Cristobal, Alajuela, Paramaribo); (3) Atlantic and Africa. Comparisons in total ozone column from soundings, the Ozone Monitoring Instrument (OMI, on Aura, 2004-) satellite and ground-based instrumentation are presented. Most stations show better agreement with OMI than they did for EPTOMS comparisons (1998-2004; Earth-ProbeTotal Ozone Mapping Spectrometer), partly due to a revised above-burst ozone climatology. Possible station biases in the stratospheric segment of the ozone measurement noted in the first 7 years of SHADOZ ozone profiles are re-examined. High stratospheric bias observed during the TOMS period appears to persist at one station. Comparisons of SHADOZ tropospheric ozone and the daily Trajectory-enhanced Tropospheric Ozone Residual (TTOR) product (based on OMIMLS) show that the satellite-derived column amount averages 25 low. Correlations between TTOR and the SHADOZ sondes are quite good (typical r2 0.5-0.8), however, which may account for why some published residual-based OMI products capture tropospheric interannual variability fairly realistically. On the other hand, no clear explanations emerge for why TTOR-sonde discrepancies vary over a wide range at most SHADOZ sites.

  2. Enhanced ozone production in a pulsed dielectric barrier discharge plasma jet with addition of argon to a He-O2 flow gas

    NASA Astrophysics Data System (ADS)

    Sands, Brian; Ganguly, Biswa; Scofield, James

    2013-09-01

    Ozone production in a plasma jet DBD driven with a 20-ns risetime unipolar pulsed voltage can be significantly enhanced using helium as the primary flow gas with an O2 coflow. The overvolted discharge can be sustained with up to a 5% O2 coflow at <20 kHz pulse repetition frequency at 13 kV applied voltage. Ozone production scales with the pulse repetition frequency up to a ``turnover frequency'' that depends on the O2 concentration, total gas flow rate, and applied voltage. For example, peak ozone densities >1016 cm-3 were measured with 3% O2 admixture and <3 W input power at a 12 kHz turnover frequency. A further increase in the repetition frequency results in increased discharge current and 777 nm O(5 P) emission, but decreased ozone production and is followed by a transition to a filamentary discharge mode. The addition of argon at concentrations >=5% reduces the channel conductivity and shifts the turnover frequency to higher frequencies. This results in increased ozone production for a given applied voltage and gas flow rate. Time-resolved Ar(1s5) and He(23S1) metastable densities were acquired along with discharge current and ozone density measurements to gain insight into the mechanisms of optimum ozone production.

  3. Ozone, ozone production rates and NO observations on the outskirts of Quito, Ecuador

    NASA Astrophysics Data System (ADS)

    Cazorla, M.

    2014-12-01

    Air quality measurements of ambient ozone, ozone production rates and nitrogen oxides, in addition to baseline meterology observations, are being taken at a recently built roof-top facility on the campus of Universidad San Francisco de Quito, in Ecuador. The measurement site is located in Cumbayá, a densely populated valley adjacent to the city of Quito. Time series of ozone and NO are being obtained with commercial air quality monitors. Rush-hour peaks of NO, above 100 ppb, have been observed, while daytime ozone levels are low. In addition, ozone production rates are being measured with the Ecuadorian version of the MOPS, Measurement of Ozone Production Sensor, originally built at Penn State University in 2010. NO and ozone observations and test results of measured ozone production rates will be presented.

  4. Ozone’s Impact on Public Health: Contributions from Indoor Exposures to Ozone and Products of Ozone-Initiated Chemistry

    PubMed Central

    Weschler, Charles J.

    2006-01-01

    Objective The associations between ozone concentrations measured outdoors and both morbidity and mortality may be partially due to indoor exposures to ozone and ozone-initiated oxidation products. In this article I examine the contributions of such indoor exposures to overall ozone-related health effects by extensive review of the literature as well as further analyses of published data. Findings Daily inhalation intakes of indoor ozone (micrograms per day) are estimated to be between 25 and 60% of total daily ozone intake. This is especially noteworthy in light of recent work indicating little, if any, threshold for ozone’s impact on mortality. Additionally, the present study estimates that average daily indoor intakes of ozone oxidation products are roughly one-third to twice the indoor inhalation intake of ozone alone. Some of these oxidation products are known or suspected to adversely affect human health (e.g., formaldehyde, acrolein, hydroperoxides, fine and ultrafine particles). Indirect evidence supports connections between morbidity/mortality and exposures to indoor ozone and its oxidation products. For example, cities with stronger associations between outdoor ozone and mortality tend to have residences that are older and less likely to have central air conditioning, which implies greater transport of ozone from outdoors to indoors. Conclusions Indoor exposures to ozone and its oxidation products can be reduced by filtering ozone from ventilation air and limiting the indoor use of products and materials whose emissions react with ozone. Such steps might be especially valuable in schools, hospitals, and childcare centers in regions that routinely experience elevated outdoor ozone concentrations. PMID:17035131

  5. Direct ozone production rate measurements and their use in assessing ozone source and receptor regions for Houston in 2013

    NASA Astrophysics Data System (ADS)

    Baier, Bianca C.; Brune, William H.; Lefer, Barry L.; Miller, David O.; Martins, Douglas K.

    2015-08-01

    Mitigating ozone pollution involves reducing ozone production and relies on complex air-quality models to design reduction strategies and determine their effectiveness. However, modeled ozone does not always agree with observations. A complementary approach is to measure the ozone production rate directly, leading to the development of the Measurement of Ozone Production Sensor (MOPS). Two improved second-generation MOPSv2s were deployed for NASA's DISCOVER-AQ field campaign in September 2013 at the University of Houston, 5 km south of downtown, and Smith Point, at the mouth of the Houston Ship Channel. Median September P(O3) was low, consistent with the observed ambient ozone. The MOPSv2s provided statistically similar results when they were compared for 8 day sat the University of Houston. October measurements yielded a median ozone production rate of 27 ± 11 ppbv hr-1, falling within the range of calculated P(O3) from prior Houston field campaigns in 2006 and 2009. Additionally, diurnal patterns are similar to model-derived ozone production from these previous campaigns. An advection analysis for a high ozone event on 25 September 2013 indicates that the Houston site was in a local ozone source region, while Smith Point ozone was likely enhanced by transport from other areas.

  6. Stratospheric Ozone: Transport, Photochemical Production and Loss

    NASA Technical Reports Server (NTRS)

    Douglass, A. R.; Kawa, S. R.; Jackman, C. H.

    2003-01-01

    Observations from various satellite instruments (e.g., Total Ozone Mapping Spectrometer (TOMS), Halogen Occultation Experiment (HALOE), Microwave Limb Sounder (MLS)) specify the latitude and seasonal variations of total ozone and ozone as a function of altitude. These seasonal variations change with latitude and altitude partly due to seasonal variation in transport and temperature, partly due to differences in the balance between photochemical production and loss processes, and partly due to differences in the relative importance of the various ozone loss processes. Comparisons of modeled seasonal ozone behavior with observations test the following: the seasonal dependence of dynamical processes where these dominate the ozone tendency; the seasonal dependence of photochemical processes in the upper stratosphere; and the seasonal change in the balance between photochemical and dynamical processes.

  7. Electrochemical production of ozone and hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Murphy, Oliver J. (Inventor); Hitchens, G. Duncan (Inventor)

    1999-01-01

    Methods of using ozone have been developed which sterilize instruments and medical wastes, oxidize organics found in wastewater, clean laundry, break down contaminants in soil into a form more readily digested by microbes, kill microorganisms present in food products, and destroy toxins present in food products. The preferred methods for killing microorganisms and destroying toxins use pressurized, humidified, and concentrated ozone produced by an electrochemical cell.

  8. Thermochemical Kinetics for Multireference Systems: Addition Reactions of Ozone

    SciTech Connect

    Zhao, Yan; Tishchenko, Oksana; Gour, Jeffrey R.; Li, Wei; Lutz, Jesse; Piecuch, Piotr; Truhlar, Donald G.

    2009-05-14

    The 1,3-dipolar cycloadditions of ozone to ethyne and ethene provide extreme examples of multireference singlet-state chemistry, and they are examined here to test the applicability of several approaches to thermochemical kinetics of systems with large static correlation. Four different multireference diagnostics are applied to measure the multireference characters of the reactants, products, and transition states; all diagnostics indicate significant multireference character in the reactant portion of the potential energy surfaces. We make a more complete estimation of the effect of quadruple excitations than was previously available, and we use this with CCSDT/CBS estimation of Wheeler et al. (Wheeler, S. E.; Ess, D. H.; Houk, K. N. J. Phys. Chem. A 2008, 112, 1798.) to make new best estimates of the van der Waals association energy, the barrier height, and the reaction energy to form the cycloadduct for both reactions. Comparing with these best estimates, we present comprehensive mean unsigned errors for a variety of coupled cluster, multilevel, and density functional methods. Several computational aspects of multireference reactions are considered: (i) the applicability of multilevel theory, (ii) the convergence of coupled cluster theory for reaction barrier heights, (iii) the applicability of completely renormalized coupled cluster methods to multireference systems, (iv) the treatment by density functional theory, (v) the multireference perturbation theory for multireference reactions, and (vi) the relative accuracy of scaling-type multilevel methods as compared with additive ones. It is found that scaling-type multilevel methods do not perform better than the additive-type multilevel methods. Among the 48 tested density functionals, only M05 reproduces the best estimates within their uncertainty. Multireference perturbation theory based on the complete-active-space reference wave functions constructed using a small number of reaction-specific active orbitals

  9. A theoretical study of the ozonolysis of C60: primary ozonide formation, dissociation, and multiple ozone additions.

    PubMed

    Chapleski, Robert C; Morris, John R; Troya, Diego

    2014-04-01

    We present an investigation of the reaction of ozone with C60 fullerene using electronic structure methods. Motivated by recent experiments of ozone exposure to a C60 film, we have characterized stationary points in the potential energy surface for the reactions of O3 with C60 that include both the formation of primary ozonide and subsequent dissociation reactions of this intermediate that lead to C-C bond cleavage. We have also investigated the addition of multiple O3 molecules to the C60 cage to explore potential reaction pathways under the high ozone flux conditions used in recent experiments. The lowest-energy product of the reaction of a single ozone molecule with C60 that results in C-C bond breakage corresponds to an open-cage C60O3 structure that contains ester and ketone moieties at the seam. This open-cage product is of much lower energy than the C60O + O2 products identified in prior work, and it is consistent with IR experimental spectra. Subsequent reaction of the open-cage C60O3 product with a second ozone molecule opens a low-energy reaction pathway that results in cage degradation via the loss of a CO2 molecule. Our calculations also reveal that, while full ozonation of all bonds between hexagons in C60 is unlikely even under high ozone concentration, the addition of a few ozone molecules to the C60 cage is favorable at room temperature. PMID:24549406

  10. TES V006 L2 Ozone Product Reprocessing Complete

    Atmospheric Science Data Center

    2015-03-18

    TES V006 L2 Ozone Product Reprocessing Complete Wednesday, February 18, 2015 An improvement in the TES Level 2 ozone species retrieval quality flag algorithm was implemented to utilize the TES water and atmospheric temperature retrievals in the ozone quality determination.  Updates to the V006 TES Level 2 ozone standard ...

  11. Ozone production by dermatologic phototherapy equipment

    SciTech Connect

    Edwards, E.K. Jr.

    1981-10-01

    Phototherapy is an extremely effective and popular physical modality used by many dermatologists to treat a wide variety of cutaneous disorders. The major dermatologic journals frequently have articles on new applications for phototherapy. The science of photobiology has advanced rapidly over the last ten years and probably will continue to do so. One fact that should be kept in mind when using an ultraviolet light apparatus is the possibility of the generation of ozone, a toxic gas. In this study, a number of devices commonly used by many dermatologists in phototherapy were monitored for ozone production. Although some of the equipment examined can produce ozone, it is produced at very low levels, dissipates quickly, and poses no health threat.

  12. Ozone production in summer in the megacities of Tianjin and Shanghai, China: a comparative study

    NASA Astrophysics Data System (ADS)

    Ran, Liang; Zhao, Chunsheng

    2013-04-01

    Rapid economic growth has given rise to a significant increase in ozone precursor emissions in many regions of China, especially in the densely populated North China Plain (NCP) and Yangtze River Delta (YRD). Improved understanding of ozone formation in response to different precursor emissions is imperative to address the highly nonlinear ozone problem and to provide a solid scientific basis for efficient ozone abatement in these regions. A comparative study on ozone photochemical production in summer has thus been carried out in the megacities of Tianjin (NCP) and Shanghai (YRD). Two intensive field campaigns were carried out respectively at an urban and a suburban site of Tianjin, in addition to routine monitoring of trace gases in Shanghai, providing data sets of surface ozone and its precursors including nitrogen oxides (NOx) and various non-methane hydrocarbons (NMHCs). Ozone pollution in summer was found to be more severe in the Tianjin region than in the Shanghai region, based on either the frequency or the duration of high ozone events. High ozone concentrations (>80 ppbv) of long duration (>6h) were frequently encountered in both urban and suburban Tianjin, while the occurrence of high ozone concentrations lasted for a shorter period (usually <4h) and had a much lower frequency in Shanghai. Such differences might be attributed to the large amount of highly reactive NMHCs in Tianjin. Model simulations based on measurements also reveal similar dependence of ozone production rates upon NMHC reactivity. Industry related species like light alkenes were of particular importance in both urban and suburban Tianjin, while in Shanghai aromatics dominated. In general, the ozone problem in Shanghai is on an urban scale. Stringent control policies on local emissions would help reduce the occurrence of high ozone concentrations. By contrast, ozone pollution in Tianjin is probably a regional problem. Combined efforts to reduce ozone precursor emissions on a regional

  13. A Status Report on the SHADOZ (Southern Hemisphere Additional Ozonesondes) Project and Some Issues Affecting Ozone Climatology

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Witte, J. C.; McPeters, R. D.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    SHADOZ aims to support the study of local and global patterns in stratospheric and tropospheric ozone and to provide a data set for the validation for satellite products and model calculations of ozone. Southern hemispheric tropical ozone is of particular interest because this region appears to have complex interplay among photochemical ozone formation (from biomass burning and lightning), stratospheric dynamics, convection and possibly cross-hemispheric transport. Balloon-borne ozone instrumentation (ozonesondes), joined with standard radiosondes for measurement of pressure, temperature and relative humidity, is used to collect profiles throughout the troposphere and lower- to mid-stratosphere. A network of 10 southern hemisphere tropical and subtropical stations, called the Southern Hemisphere ADditional OZonesondes (SHADOZ) project, has been established from operational sites to assemble sonde data for 1998-2000. A status report on the archive, with station operating characteristics, will be given, along with some operational issues that may affect data analysis and interpretation.

  14. Tropospheric ozone production regions and the intercontinental origins of surface ozone over Europe

    NASA Astrophysics Data System (ADS)

    Derwent, Richard G.; Utembe, Steven R.; Jenkin, Michael E.; Shallcross, Dudley E.

    2015-07-01

    Ozone tagged labelling schemes have been implemented in a global Lagrangian chemistry-transport model to identify the intercontinental origins of surface ozone in Europe. Stratosphere-troposphere exchange gave rise to between 3 and 5 ppb across Europe, whereas the mid-latitudes of the Middle East, Asia and the Pacific Ocean region contributed 6-8 ppb. Surface ozone levels of 10-16 ppb were associated with the mid-latitudes of North America and the North Atlantic Ocean regions. Appreciable intercontinental ozone production occurred downwind of continental regions and above the surface layer. Intercontinental ozone formation and transport from tropical regions contributed about 4 ppb and was much less efficient compared with that from mid-latitudes. There were approaching 60 chemical processes driving intercontinental ozone formation, of which the HO2 + NO, CH3O2 + NO and CH3COO2 + NO reactions were the most important. Ozone production appeared to be driven by OH oxidation of secondary reaction products rather than the oxidation of primary emitted VOCs. The largest intercontinental ozone contributions amounted to about 20 ppb from North America to European baseline stations, 14 ppb from Asia to North American baseline stations and 10 ppb from Asia to European baseline stations. It is possible that changing intercontinental ozone production and transport could have led to seasonal ozone trends and shifts in seasonal cycles at northern hemisphere mid-latitude baseline ozone monitoring stations.

  15. User's guide for SBUV/TOMS ozone derivative products

    NASA Technical Reports Server (NTRS)

    Fleig, A. J.; Wellemeyer, C.; Oslik, N.; Lee, D.; Miller, J.; Magatani, R.

    1984-01-01

    A series of products are available derived from the total-ozone and ozone vertical profile results for the Solar Backscattered Ultraviolet/Total-Ozone Mapping Spectrometer (SBUV/TOMS) Nimbus-7 operation. Products available are (1) orbital height-latitude cross sections of the SBUV profile data, (2) daily global total ozone contours in polar coordinates, (3) daily averages of total ozone in global 5x5 degree latitude-longitude grid, (4) daily, monthly and quarterly averages of total ozone and profile data in 10 degree latitude zones, (5) tabular presentation of zonal means, (6) daily global total ozone and profile contours in polar coordinates. The ""Derivative Products User's Guide'' describes each of these products in detail, including their derivation and presentation format. Information is provided on how to order the tapes and microfilm from the National Space Science Data Center.

  16. Aromatic VOCs global influence in the ozone production

    NASA Astrophysics Data System (ADS)

    Cabrera-Perez, David; Pozzer, Andrea

    2016-04-01

    Aromatic hydrocarbons are a subgroup of Volatile Organic Compounds (VOCs) of special interest in the atmosphere of urban and semi-urban areas. Aromatics form a high fraction of VOCs, are highly reactive and upon oxidation they are an important source of ozone. These group of VOCs are released to the atmosphere by processes related to biomass burning and fossil fuel consumption, while they are removed from the atmosphere primarily by OH reaction and by dry deposition. In addition, a branch of aromatics (ortho-nitrophenols) produce HONO upon photolysis, which is responsible of certain amount of the OH recycling. Despite their importance in the atmosphere in anthropogenic polluted areas, the influence of aromatics in the ozone production remains largely unknown. This is of particular relevance, being ozone a pollutant with severe side effects on air quality, health and climate. In this work the atmospheric impacts at global scale of the most emitted aromatic VOCs in the gas phase (benzene, toluene, xylenes, ethylbenzene, styrene, phenol, benzaldehyde and trimethylbenzenes) are analysed and assessed. Specifically, the impact on ozone due to aromatic oxidation is estimated, as this is of great interest in large urban areas and can be helpful for developing air pollution control strategies. Further targets are the quantification of the NOx loss and the OH recycling due to aromatic oxidation. In order to investigate these processes, two simulations were performed with the numerical chemistry and climate simulation ECHAM/MESSy Atmospheric Chemistry (EMAC) model. The simulations compare two cases, one with ozone concentrations when aromatics are present or the second one when they are missing. Finally, model simulated ozone is compared against a global set of observations in order to better constrain the model accuracy.

  17. Study on the kinetics and transformation products of salicylic acid in water via ozonation.

    PubMed

    Hu, Ruikang; Zhang, Lifeng; Hu, Jiangyong

    2016-06-01

    As salicylic acid is one of widely used pharmaceuticals, its residue has been found in various environmental water systems e.g. wastewater, surface water, treated water and drinking water. It has been reported that salicylic acid can be efficiently removed by advanced oxidation processes, but there are few studies on its transformation products and ozonation mechanisms during ozonation process. The objective of this study is to characterize the transformation products, investigate the degradation mechanisms at different pH, and propose the ozonation pathways of salicylic acid. The results showed that the rate of degradation was about 10 times higher at acidic condition than that at alkaline condition in the first 1 min when 1 mg L(-1) of ozone solution was added into 1 mg L(-1) of salicylic acid solution. It was proposed that ozone direct oxidation mechanism dominates at acidic condition, while indirect OH radical mechanism dominates at alkaline condition. A two stages pseudo-first order reaction was proposed at different pH conditions. Various hydroxylation products, carbonyl compounds and carboxylic acids, such as 2,5-dihydroxylbenzoic acid, 2,3-dihydroxylbenzoic acid, catechol, formaldehyde, glyoxal, acetaldehyde, maleic acid, acetic acid and oxalic acid etc. were identified as ozonation transformation products. In addition, acrylic acid was identified, for the first time, as ozonation transformation products through high resolution liquid chromatography-time of flight mass spectrometer. The information demonstrated in this study will help us to better understand the possible effects of ozonation products on the water quality. The degradation pathways of salicylic acid by ozonation in water sample were proposed. As both O3 and OH radical were important in the reactions, the degradation pathways of salicylic acid by ozonation in water sample were proposed at acidic and basic conditions. To our knowledge, there was no integrated study reported on the ozonation of

  18. Ozone production by a dc corona discharge in air contaminated by n-heptane

    NASA Astrophysics Data System (ADS)

    Pekárek, S.

    2008-01-01

    Beneficial purposes of ozone such as elimination of odours, harmful bacteria and mildew can be used for transportation of food, fruits and vegetables with the aim to extend their storage life. To date the main technique used for this purpose in the transportation of these commodities, e.g. by trucks, was cooling. Here a combination of cooling together with the supply of ozone into containers with these commodities is considered. For these purposes we studied the effect of air contamination by n-heptane (part of automotive fuels) and humidity on ozone production by a dc hollow needle to mesh corona discharge. We found that, for both polarities of the needle electrode, addition of n-heptane to air (a) decreases ozone production; (b) causes discharge poisoning to occur at lower current than for air; (c) does not substantially influence the current for which the ozone production reaches the maximum. Finally the maximum ozone production for the discharge in air occurs for the same current as the maximum ozone production for the discharge contaminated by n-heptane. We also found that humidity decreases ozone production from air contaminated by n-heptane irrespective of the polarity of the coronating needle electrode. This dependence is stronger for the discharge with the needle biased positively.

  19. Products of BVOC oxidation: ozone and organic aerosols

    NASA Astrophysics Data System (ADS)

    Wildt, Jürgen; Andres, Stefanie; Carriero, Giulia; Ehn, Mikael; Fares, Silvano; Hoffmann, Thorsten; Hacker, Lina; Kiendler-Scharr, Astrid; Kleist, Einhard; Paoletti, Elena; Pullinen, Iida; Rohrer, Franz; Rudich, Yinon; Springer, Monika; Tillmann, Ralf; Wahner, Andreas; Wu, Cheng; Mentel, Thomas

    2015-04-01

    Biogenic Volatile Organic Compounds (BVOC) are important precursors in photochemical O3 and secondary organic aerosol (SOA) formation. We conducted a series of laboratory experiments with OH-induced oxidation of monoterpenes to elucidate pathways and efficiencies of O3 and SOA formation. At high NOx conditions ([BVOC] / [NOx] < 7 ppbC / ppb) photochemical ozone formation was observed. For -pinene as individual BVOC as well as for the monoterpene mixes emitted from different plant species we observed increasing ozone formation with increasing [NOX]. Between 2 and 3 O3-molecules were formed from 1 monoterpene when ozone formation was BVOC limited. Under such high NOX conditions, new particle formation was suppressed. Increasing [BVOC] / [NOX] ratios caused increasing efficiency of new particle formation indicating that peroxy radicals are the key intermediates in both, photochemical ozone- and new particle formation. The classical chemistry of peroxy radicals is well established (e.g. Master Chemical Mechanism). Peroxy radicals are produced by addition of molecular oxygen to the alkyl radical formed after OH attack at the BVOC. They either react with NO which leads to ozone formation or they react with other peroxy radicals and form chemically stable products (hydroperoxides, alkoholes and ketones). Much less knowledge exists on such reactions for Highly Oxidized Peroxy Radicals, (HOPR). Such HOPR were observed during ozonolysis of several volatiles and, in case of monoterpenes as precursors, they can contain more than 12 Oxygen atoms (Mentel et al., 2015). Although the OH-initiated formation of HOPR is yet not fully understood, their basic gas phase reactions seem to follow classical photochemical rules. In reactions with NO they can act as precursor for O3 and in reactions with other HOPR or with classical less oxidized peroxy radicals they can form highly oxidized stable products and alkoxy radicals. In addition, HOPR-HOPR reactions lead to the formation of

  20. Ozone production in four major cities of China: sensitivity to ozone precursors and heterogeneous processes

    NASA Astrophysics Data System (ADS)

    Xue, L. K.; Wang, T.; Gao, J.; Ding, A. J.; Zhou, X. H.; Blake, D. R.; Wang, X. F.; Saunders, S. M.; Fan, S. J.; Zuo, H. C.; Zhang, Q. Z.; Wang, W. X.

    2013-10-01

    Despite a large volume of research over a number of years, our understandings of the key precursors that control tropospheric ozone production and the impacts of heterogeneous processes remain incomplete. In this study, we analyze measurements of ozone and its precursors made at rural/suburban sites downwind of four large Chinese cities - Beijing, Shanghai, Guangzhou and Lanzhou. At each site the same measurement techniques were utilized and a photochemical box model based on the Master Chemical Mechanism (v3.2) was applied, to minimize uncertainties in comparison of the results due to differences in methodology. All four cities suffered from severe ozone pollution. At the rural site of Beijing, export of the well-processed urban plumes contributed to the extremely high ozone levels (up to an hourly value of 286 ppbv), while the pollution observed at the suburban sites of Shanghai, Guangzhou and Lanzhou was characterized by intense in-situ ozone production. The major anthropogenic hydrocarbons were alkenes and aromatics in Beijing and Shanghai, aromatics in Guangzhou, and alkenes in Lanzhou. The ozone production was found to be in a VOCs-limited regime in both Shanghai and Guangzhou, and a mixed regime in Lanzhou. In Shanghai, the ozone formation was most sensitive to aromatics and alkenes, while in Guangzhou aromatics were the predominant ozone precursors. In Lanzhou, either controlling NOx or reducing emissions of olefins from the petrochemical industry would mitigate the local ozone production. The potential impacts of several heterogeneous processes on the ozone formation were assessed. The hydrolysis of dinitrogen pentoxide (N2O5), uptake of the hydroperoxyl radical (HO2) on particles, and surface reactions of NO2 forming nitrous acid (HONO) present considerable sources of uncertainty in the current studies of ozone chemistry. Further efforts are urgently required to better understand these processes and refine atmospheric models.

  1. Ozonation of piperidine, piperazine and morpholine: Kinetics, stoichiometry, product formation and mechanistic considerations.

    PubMed

    Tekle-Röttering, Agnes; Jewell, Kevin S; Reisz, Erika; Lutze, Holger V; Ternes, Thomas A; Schmidt, Winfried; Schmidt, Torsten C

    2016-01-01

    Piperidine, piperazine and morpholine as archetypes for secondary heterocyclic amines, a structural unit that is often present in pharmaceuticals (e.g., ritalin, cetirizine, timolol, ciprofloxacin) were investigated in their reaction with ozone. In principle the investigated compounds can be degraded with ozone in a reasonable time, based on their high reaction rate constants with respect to ozone (1.9 × 10(4)-2.4 × 10(5) M(-1) s(-1)). However, transformation is insufficient (13-16%), most likely due to a chain reaction, which decomposes ozone. This conclusion is based on OH scavenging experiments, leading to increased compound transformation (18-27%). The investigated target compounds are similar in their kinetic and stoichiometric characteristics. However, the mechanistic considerations based on product formation indicate various reaction pathways. Piperidine reacts with ozone via a nonradical addition reaction to N-hydroxypiperidine (yield: 92% with and 94% without scavenging, with respect to compound transformation). However, piperazine degradation with ozone does not lead to N-hydroxypiperazine. In the morpholine/ozone reaction, N-hydroxymorpholine was identified. Additional oxidation pathways in all cases involved the formation of OH with high yields. One important pathway of piperazine and morpholine by ozonation could be the formation of C-centered radicals after ozone or OH radical attack. Subsequently, O2 addition forms unstable peroxyl radicals, which in one pathway loose superoxide radicals by generating a carbon-centered cation. Subsequent hydrolysis of the carbon-centered cation leads to formaldehyde, whereby ozonation of the N-hydroxy products can proceed in the same way and in addition give rise to hydroxylamine. A second pathway of the short-lived peroxyl radicals could be a dimerization to form short-lived tetraoxides, which cleave by forming hydrogen peroxide. All three products have been found. PMID:26624229

  2. Ozone production in the megacities of Tianjin and Shanghai, China: a comparative study

    NASA Astrophysics Data System (ADS)

    Ran, L.; Zhao, C. S.; Xu, W. Y.; Han, M.; Lu, X. Q.; Han, S. Q.; Lin, W. L.; Xu, X. B.; Gao, W.; Yu, Q.; Geng, F. H.; Ma, N.; Deng, Z. Z.; Chen, J.

    2012-04-01

    Rapid economic growth has given rise to a significant increase in ozone precursor emissions in many regions of China, especially in the densely populated North China Plain (NCP) and Yangtze River Delta (YRD). Improved understanding of ozone formation in response to different precursor emissions is imperative to address the highly nonlinear ozone problem and to provide a solid scientific basis for efficient ozone abatement in these regions. A comparative study on ozone photochemical production in summer has thus been carried out in the megacities of Tianjin (NCP) and Shanghai (YRD). Two intensive field campaigns were carried out respectively at an urban and a suburban site of Tianjin, in addition to routine monitoring of trace gases in Shanghai, providing data sets of surface ozone and its precursors including nitrogen oxides (NOx) and various volatile organic compounds (VOCs). Ozone pollution was found to be more severe in Tianjin than in Shanghai during the summer, either based on the frequency or the duration of high ozone events. Such differences might be attributed to the large amount of highly reactive VOC mixture in the Tianjin region. It is found that industry related species like light alkenes were of particular importance in both urban and suburban Tianjin, while in Shanghai aromatics dominate. In general, the ozone problem in Shanghai is on an urban scale. Stringent control policies on local emissions would help reduce the occurrence of high ozone concentrations. By contrast, ozone pollution in Tianjin is a regional problem. Combined efforts to reduce ozone precursor emissions on a regional scale must be undertaken to bring the ozone problem under control.

  3. Ozone production in summer in the megacities of Tianjin and Shanghai, China: a comparative study

    NASA Astrophysics Data System (ADS)

    Ran, L.; Zhao, C. S.; Xu, W. Y.; Han, M.; Lu, X. Q.; Han, S. Q.; Lin, W. L.; Xu, X. B.; Gao, W.; Yu, Q.; Geng, F. H.; Ma, N.; Deng, Z. Z.; Chen, J.

    2012-08-01

    Rapid economic growth has given rise to a significant increase in ozone precursor emissions in many regions of China, especially in the densely populated North China Plain (NCP) and Yangtze River Delta (YRD). Improved understanding of ozone formation in response to different precursor emissions is imperative to address the highly nonlinear ozone problem and to provide a solid scientific basis for efficient ozone abatement in these regions. A comparative study on ozone photochemical production in summer has thus been carried out in the megacities of Tianjin (NCP) and Shanghai (YRD). Two intensive field campaigns were carried out respectively at an urban and a suburban site of Tianjin, in addition to routine monitoring of trace gases in Shanghai, providing data sets of surface ozone and its precursors including nitrogen oxides (NOx) and various non-methane hydrocarbons (NMHCs). Ozone pollution in summer was found to be more severe in the Tianjin region than in the Shanghai region, based on either the frequency or the duration of high ozone events. Such differences might be attributed to the large amount of highly reactive NMHCs in Tianjin. Industry related species like light alkenes were of particular importance in both urban and suburban Tianjin, while in Shanghai aromatics dominated. In general, the ozone problem in Shanghai is on an urban scale. Stringent control policies on local emissions would help reduce the occurrence of high ozone concentrations. By contrast, ozone pollution in Tianjin is probably a regional problem. Combined efforts to reduce ozone precursor emissions on a regional scale must be undertaken to bring the ozone problem under control.

  4. Nimbus 7 solar backscatter ultraviolet (SBUV) ozone products user's guide

    NASA Technical Reports Server (NTRS)

    Fleig, Albert J.; Mcpeters, R. D.; Bhartia, P. K.; Schlesinger, Barry M.; Cebula, Richard P.; Klenk, K. F.; Taylor, Steven L.; Heath, Donald F.

    1990-01-01

    Three ozone tape products from the Solar Backscatter Ultraviolet (SBUV) experiment aboard Nimbus 7 were archived at the National Space Science Data Center. The experiment measures the fraction of incoming radiation backscattered by the Earth's atmosphere at 12 wavelengths. In-flight measurements were used to monitor changes in the instrument sensitivity. Total column ozone is derived by comparing the measurements with calculations of what would be measured for different total ozone amounts. The altitude distribution is retrieved using an optimum statistical technique for the inversion. The estimated initial error in the absolute scale for total ozone is 2 percent, with a 3 percent drift over 8 years. The profile error depends on latitude and height, smallest at 3 to 10 mbar; the drift increases with increasing altitude. Three tape products are described. The High Density SBUV (HDSBUV) tape contains the final derived products - the total ozone and the vertical ozone profile - as well as much detailed diagnostic information generated during the retrieval process. The Compressed Ozone (CPOZ) tape contains only that subset of HDSBUV information, including total ozone and ozone profiles, considered most useful for scientific studies. The Zonal Means Tape (ZMT) contains daily, weekly, monthly and quarterly averages of the derived quantities over 10 deg latitude zones.

  5. New Insights on Tropical Ozone from SHADOZ (Southern Hemisphere Additional Ozonesondes) Profiles

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.

    2004-01-01

    The SHADOZ (Southern Hemisphere Additional Ozonesondes) ozone sounding network was initiated in 1998 to improve the coverage of tropical in-situ ozone measurements for satellite validation, algorithm development and related process studies. Over 2000 soundings have been archived at the website, , for 12 stations: Ascension Island; Nairobi and Malindi, Kenya; Irene, South Africa; Reunion Island, Watukosek, Java; Fiji; Tahiti; American Samoa; San Cristobal, Galapagos; Natal, Brazil; Paramaribo, Surinam. Key results from SHADOZ will be described from among the following: 1) By using ECC sondes with similar procedures, 5-10% accuracy and precision (1-sigma) of the sonde total ozone measurement was achieved; 2) Week-to-week variability in tropospheric ozone is so great that statistics are frequently not Gaussian; most stations vary up to a factor of 3 in tropospheric column over the course of a year; 3) Longitudinal variability in tropospheric ozone profiles is a consistent feature, with a 10-15 DU column-integrated difference between Atlantic and Pacific sites; this causes a "zonal wave-one" feature in total ozone. 4) The ozone record from Paramaribo, Surinam (6N, 55W) is a marked contrast to southern tropical ozone because Surinam is often north of the Intertropical Convergence Zone; 5) Indian Ocean region pollution may contribute up to half of the excess ozone observed in the south tropical Atlantic paradox in the December-January-February period of the year.

  6. Forests and ozone: productivity, carbon storage, and feedbacks

    PubMed Central

    Wang, Bin; Shugart, Herman H.; Shuman, Jacquelyn K.; Lerdau, Manuel T.

    2016-01-01

    Tropospheric ozone is a serious air-pollutant, with large impacts on plant function. This study demonstrates that tropospheric ozone, although it damages plant metabolism, does not necessarily reduce ecosystem processes such as productivity or carbon sequestration because of diversity change and compensatory processes at the community scale ameliorate negative impacts at the individual level. This study assesses the impact of ozone on forest composition and ecosystem dynamics with an individual-based gap model that includes basic physiology as well as species-specific metabolic properties. Elevated tropospheric ozone leads to no reduction of forest productivity and carbon stock and to increased isoprene emissions, which result from enhanced dominance by isoprene-emitting species (which tolerate ozone stress better than non-emitters). This study suggests that tropospheric ozone may not diminish forest carbon sequestration capacity. This study also suggests that, because of the often positive relationship between isoprene emission and ozone formation, there is a positive feedback loop between forest communities and ozone, which further aggravates ozone pollution. PMID:26899381

  7. CAFS ozone column data for validation of the AURA ozone products

    NASA Astrophysics Data System (ADS)

    Shetter, R.; Petropavlovskikh, I.; Hall, S. R.; Froidevaux, L.; Bhartia, P. K.; Kroon, M.

    2005-12-01

    Highly resolved UV and Visible actinic flux measurements were taken by the CCD Actinic Flux Spectrometer (CAFS) instrument (R. Shetter, NCAR) on board of the WB-57 aircraft as part of the Aura Validation Experiment (AVE) campaign in Texas in 2004. The algorithm was developed and field-tested to derive partial ozone column products from the CAFS measurements. An intensive data set of partial ozone columns measured along the tracks of the Aura satellite has been provided for the first-round satellite validation. Preliminary analysis of the CAFS measurements revealed that small corrections to the instrument-weighted solar spectrum data were required. On its second deployment in January 2005, the CAFS instrument was flown on board of the DC-8 aircraft as part of the Polar AVE campaign. Partial ozone column data above 12 km were derived under the difficult conditions of low-sun and high ozone variability. The tropospheric ozone climatology (McPeters et al, 2004) was used for the unaccounted lower part of the ozone column below the aircraft altitude. The set of combined CAFS and climatological data was successfully used for validation of the OMI total ozone column under low-sun conditions (solar zenith angle larger than 80-degrees). Prior to the third AVE campaign in June of 2005, the CAFS instrument was modified to reduce sensitivity of the measurement to the variability of scattered light over inhomogeneous background. New look-up tables were developed and CAFS measurements have been analyzed. The preliminary results suggest that the measurement has become more sensitive to the aircraft roll and pitch movements. We will present results of the OMI total ozone column validation at different atmospheric conditions including a large range of total ozone columns and solar zenith angles, multiple altitudes, and underlying surface albedo. The MLS/Aura ozone profiles have been derived for the last three AVE campaigns. The co-incidental MLS ozone profiles were integrated above

  8. Ozone production from wildfires: A critical review

    NASA Astrophysics Data System (ADS)

    Jaffe, Daniel A.; Wigder, Nicole L.

    2012-05-01

    Tropospheric ozone (O3) negatively impacts human health and ecosystems, and is a greenhouse gas. Wildfires are a source of tropospheric O3, and studies show that wildfires are increasing in North America. In this study, we present a critical review of O3 production from wildfires focusing on three key topics: the influence of wildfire emissions on O3 production; the influence of photochemistry on wildfire O3 production; and regulatory issues associated with wildfire O3 production in the United States. Observations of ΔO3/ΔCO range from approximately -0.1 to 0.9, and are caused by the interplay of numerous factors including fire emissions, efficiency of combustion, chemical and photochemical reactions, aerosol effects on chemistry and radiation, and local and downwind meteorological patterns. Using average ΔO3/ΔCO ratios for major biomes, we estimate global wildfires produce approximately 170 Tg of O3 per year, which is 3.5% of all global tropospheric O3 production. Areas of uncertainty in wildfire O3 production include the net effect of aerosols on chemical and photochemical reactions within a fire plume, the impact of oxygenated volatile organic compounds and nitrous acid on O3 production, and the interplay of variables that lead to extreme ΔO3/ΔCO values. Because wildfire frequencies are likely increasing and have been shown to contribute to elevated O3 at air quality monitoring sites, it is important to better understand the emissions, photochemistry and impacts of these fires.

  9. Addition of hydrogen peroxide for the simultaneous control of bromate and odor during advanced drinking water treatment using ozone.

    PubMed

    Wang, Yongjing; Yu, Jianwei; Zhang, Dong; Yang, Min

    2014-03-01

    Complete removal of the characteristic septic/swampy odor from Huangpu River source water could only be achieved under an ozone dose as high as 4.0 mg/L in an ozone-biological activated carbon (O3-BAC) process, which would lead to the production of high concentrations of carcinogenic bromate due to the high bromide content. This study investigated the possibility of simultaneous control of bromate and the septic/swampy odor by adding H2O2 prior to the O3-BAC process for the treatment of Huangpu River water. H2O2 addition could reduce the bromate concentration effectively at an H2O2/O3 (g/g) ratio of 0.5 or higher. At the same time, the septic/swampy odor removal was enhanced by the addition of H2O2, although optimization of the H2O2/O3 ratio was required for each ozone dose. At an ozone dose of 2.0 mg/L, the odor was removed completely at an H2O2/O3 ratio of 0.5. The results indicated that H2O2 application at a suitable dose could enhance the removal of the septic/swampy odor while suppressing the formation of bromate during ozonation of Huangpu River source water. PMID:25079267

  10. A Multi-sensor Upper Tropospheric Ozone Product (MUTOP) based on TES ozone and GOES water vapor: validation with ozonesondes

    NASA Astrophysics Data System (ADS)

    Moody, J. L.; Felker, S. R.; Wimmers, A. J.; Osterman, G.; Bowman, K.; Thompson, A. M.; Tarasick, D. W.

    2011-11-01

    Accurate representation of ozone in the extratropical upper troposphere (UT) remains a challenge. However, the implementation of hyper-spectral remote sensing using satellite instruments such as the Tropospheric Emission Spectrometer (TES) provides an avenue for mapping ozone in this region, from 500 to 300 hPa. As a polar orbiting satellite TES observations are limited, but in this paper they are combined with geostationary satellite observations of water vapor. This paper describes a validation of the Multi-sensor UT Ozone Product (MUTOP). MUTOP is statistical retrieval method, a derived product image based on the correlation of two remotely sensed quantities, TES ozone, against geostationary (GOES) specific humidity and modeled potential vorticity, a dynamical tracer in the UT. These TES-derived UT ozone mixing ratios are compared to coincident ozonesonde measurements of layer-average UT ozone mixing ratios made during the NASA INTEX/B field campaign in the spring of 2006; the region for this study is effectively the GOES west domain covering the Eastern North Pacific Ocean and the Western United States. This intercomparison evaluates MUTOP skill at representing ozone magnitude and variability in this region of complex dynamics. In total, 11 ozonesonde launch sites were available for this study, providing 127 individual sondes for comparison; the overall mean ozone of the 500-300 hPa layer for these sondes was 78.0 ppbv. MUTOP reproduces in-situ measurements reasonably well, producing an UT mean of 82.3 ppbv, with a mean absolute error of 12.2 ppbv and a root mean square error of 16.4 ppbv relative to ozonesondes across all sites. An overall UT mean bias of 4.3 ppbv relative to sondes was determined for MUTOP. Considered in the context of past TES validation studies, these results illustrate that MUTOP is able to maintain accuracy similar to TES while expanding coverage to the entire GOES-West satellite domain. In addition MUTOP provides six-hour temporal

  11. A multi-sensor upper tropospheric ozone product (MUTOP) based on TES ozone and GOES water vapor: validation with ozonesondes

    NASA Astrophysics Data System (ADS)

    Moody, J. L.; Felker, S. R.; Wimmers, A. J.; Osterman, G.; Bowman, K.; Thompson, A. M.; Tarasick, D. W.

    2012-06-01

    Accurate representation of ozone in the extratropical upper troposphere (UT) remains a challenge. However, the implementation of hyper-spectral remote sensing using satellite instruments such as the Tropospheric Emission Spectrometer (TES) provides an avenue for mapping ozone in this region, from 500 to 300 hPa. As a polar orbiting satellite TES observations are limited, but in this paper they are combined with geostationary satellite observations of water vapor. This paper describes a validation of the Multi-sensor UT Ozone Product (MUTOP). MUTOP, based on a statistical retrieval method, is an image product derived from the multiple regression of remotely sensed TES ozone, against geostationary (GOES) specific humidity (remotely sensed) and potential vorticity (a modeled dynamical tracer in the UT). These TES-derived UT ozone mixing ratios are compared to coincident ozonesonde measurements of layer-average UT ozone mixing ratios made during the NASA INTEX/B field campaign in the spring of 2006; the region for this study is effectively the GOES west domain covering the eastern North Pacific Ocean and the western United States. This intercomparison evaluates MUTOP skill at representing ozone magnitude and variability in this region of complex dynamics. In total, 11 ozonesonde launch sites were available for this study, providing 127 individual sondes for comparison; the overall mean ozone of the 500-300 hPa layer for these sondes was 78.0 ppbv. MUTOP reproduces in~situ measurements reasonably well, producing an UT mean of 82.3 ppbv, with a mean absolute error of 12.2 ppbv and a root mean square error of 16.4 ppbv relative to ozonesondes across all sites. An overall UT mean bias of 4.3 ppbv relative to sondes was determined for MUTOP. Considered in the context of past TES validation studies, these results illustrate that MUTOP is able to maintain accuracy similar to TES while expanding coverage to the entire GOES-West satellite domain. In addition MUTOP provides six

  12. Ozone production chemistry in the presence of urban plumes.

    PubMed

    Brune, W H; Baier, B C; Thomas, J; Ren, X; Cohen, R C; Pusede, S E; Browne, E C; Goldstein, A H; Gentner, D R; Keutsch, F N; Thornton, J A; Harrold, S; Lopez-Hilfiker, F D; Wennberg, P O

    2016-07-18

    Ozone pollution affects human health, especially in urban areas on hot sunny days. Its basic photochemistry has been known for decades and yet it is still not possible to correctly predict the high ozone levels that are the greatest threat. The CalNex_SJV study in Bakersfield CA in May/June 2010 provided an opportunity to examine ozone photochemistry in an urban area surrounded by agriculture. The measurement suite included hydroxyl (OH), hydroperoxyl (HO2), and OH reactivity, which are compared with the output of a photochemical box model. While the agreement is generally within combined uncertainties, measured HO2 far exceeds modeled HO2 in NOx-rich plumes. OH production and loss do not balance as they should in the morning, and the ozone production calculated with measured HO2 is a decade greater than that calculated with modeled HO2 when NO levels are high. Calculated ozone production using measured HO2 is twice that using modeled HO2, but this difference in calculated ozone production has minimal impact on the assessment of NOx-sensitivity or VOC-sensitivity for midday ozone production. Evidence from this study indicates that this important discrepancy is not due to the HO2 measurement or to the sampling of transported plumes but instead to either emissions of unknown organic species that accompany the NO emissions or unknown photochemistry involving nitrogen oxides and hydrogen oxides, possibly the hypothesized reaction OH + NO + O2 → HO2 + NO2. PMID:27101799

  13. ADEOS Total Ozone Mapping Spectrometer (TOMS) Data Products User's Guide

    NASA Technical Reports Server (NTRS)

    Krueger, A.; Bhartia, P. K.; McPeters, R.; Herman, J.; Wellemeyer, C.; Jaross, G.; Seftor, C.; Torres, O.; Labow, G.; Byerly, W.; Moy, L.; Taylor, S.; Swissler, T.; Cebula, R.

    1998-01-01

    Two data products from the Total Ozone Mapping Spectrometer (ADEOS/TOMS) have been archived at the Distributed Active Archive Center, in the form of Hierarchical Data Format files. The ADEOS/ TOMS began taking measurements on September 11, 1996, and ended on June 29, 1997. The instrument measured backscattered Earth radiance and incoming solar irradiance; their ratio was used in ozone retrievals. Changes in the reflectivity of the solar diffuser used for the irradiance measurement were monitored using a carousel of three diffusers, each exposed to the degrading effects of solar irradiation at different rates. The algorithm to retrieve total column ozone compares measured Earth radiances at sets of three wavelengths with radiances calculated for different total ozone values, solar zenith angles, and optical paths. The initial error in the absolute scale for TOMS total ozone is 3 percent, the one standard deviation random error is 2 percent, and the drift is less than 0.5 percent over the 9-month data record. The Level 2 product contains the measured radiances, the derived total ozone amount, and reflectivity information for each scan position. The Level 3 product contains daily total ozone and reflectivity in a 1-degree latitude by 1.25 degrees longitude grid. The Level 3 files containing estimates of UVB at the Earth surface and tropospheric aerosol information will also be available. Detailed descriptions of both HDF data files and the CDROM product are provided.

  14. Surface Ozone Effects on Productivity Using a Biogeochemistry Model

    NASA Astrophysics Data System (ADS)

    Felzer, B. S.; Kicklighter, D. W.; Melillo, J. M.; Wang, C.; Zhuang, Q.

    2002-05-01

    The effects of air pollution on vegetation may provide another important control on the carbon cycle that has not yet been widely considered. Prolonged exposure to high levels of ozone, in particular, has been observed to inhibit photosynthesis by direct cellular damage within the leaves. This ozone exposure also indirectly affects photosynthesis, as well as nitrogen uptake and water availability, through changes in stomatal conductance. We have incorporated simple empirical equations derived for hardwoods, conifers, and croplands into the Terrestrial Ecosystem Model (TEM, version 4.2). These equations linearly relate gross primary productivity (GPP) to accumulated hourly ozone levels above a threshold of 40 ppb, such that productivity in regions with high ozone levels is reduced. Indirect effects of ozone have been incorporated by limiting nitrogen uptake, evapotranspiration (which limits further CO2 uptake and increases water availability), and ozone uptake in the month following exposure. Evaluation of TEM with data from a mixed hardwood stand at the Harvard Forest shows a 5% reduction in Net Primary Productivity (NPP) as a result of observed ozone levels. At this site, the most important factor influencing the reduction of NPP in the model is the reduction of N uptake. We also ran TEM with a business-as-usual scenario for ozone during the 21st century, using a 2D atmospheric chemistry model developed at MIT. Results for the U.S. show the largest reduction of NPP throughout the transient simulation occurs in the Northeast and upper Midwest, consistent with the regions of largest ozone exposure. The reduction in carbon accumulation by terrestrial ecosystems from 123 years of ozone exposure is 1.6 Pg C (which constitutes a 10% reduction). While these results are not significant for continental-scale carbon sequestration, they may have important implications for more localized carbon budgets.

  15. Removal and transformation products of ibuprofen obtained during ozone- and ultrasound-based oxidative treatment.

    PubMed

    Yargeau, Viviane; Danylo, Félix

    2015-01-01

    The oxidation of ibuprofen (IBP) in water was evaluated using oxidative treatments: ozonation, sonication, hydrogen peroxide addition and combinations of these processes. After 20 minutes of treatment, ozone coupled with hydrogen peroxide at pH 7, 15 °C, an ozone dose of 16 mg/L and a hydrogen peroxide concentration of 7.1 mg/L was found to have the highest IBP (95%) and chemical oxygen demand (COD) (41%) removals. A synergistic effect was observed for the combined ozonation/sonication process, which might be explained by an improved mass transfer of ozone in the solution due to the presence of ultrasonic pressure waves. Transformation products were detected in the treated solutions. The nature of five of these products was confirmed by liquid chromatography-mass spectrometry (LC-MS), including 4-isobutylacetophenone (4-IBAP), oxo-IBP, 4-acetylbenzoic acid, 4-ethybenzaldehyde and oxalic acid. In addition, COD analyses for each experiment showed that the ratio of %COD removal to %IBP removal was highest with sonication; suggesting that this oxidative process offers other mechanisms of removal which may lead to further degradation of products formed. This study presents the first data on removal of IBP by sonication coupled to ozonation and provides some insight into the potential of this combined treatment approach for the removal of contaminants of emerging concern. PMID:26204083

  16. Phospholipid Ozonation Products Activate the 5-Lipoxygenase Pathway in Macrophages.

    PubMed

    Zemski Berry, Karin A; Murphy, Robert C

    2016-08-15

    Ozone is a highly reactive environmental toxicant that can react with the double bonds of lipids in pulmonary surfactant. This study was undertaken to investigate the proinflammatory properties of the major lipid-ozone product in pulmonary surfactant, 1-palmitoyl-2-(9'-oxo-nonanoyl)-glycerophosphocholine (16:0/9al-PC), with respect to eicosanoid production. A dose-dependent increase in the formation of 5-lipoxygenase (5-LO) products was observed in murine resident peritoneal macrophages (RPM) and alveolar macrophages (AM) upon treatment with 16:0/9al-PC. In contrast, the production of cyclooxygenase (COX) derived eicosanoids did not change from basal levels in the presence of 16:0/9al-PC. When 16:0/9al-PC and the TLR2 ligand, zymosan, were added to RPM or AM, an enhancement of 5-LO product formation along with a concomitant decrease in COX product formation was observed. Neither intracellular calcium levels nor arachidonic acid release was influenced by the addition of 16:0/9al-PC to RPM. Results from mitogen-activated protein kinase (MAPK) inhibitor studies and direct measurement of phosphorylation of MAPKs revealed that 16:0/9al-PC activates the p38 MAPK pathway in RPM, which results in the activation of 5-LO. Our results indicate that 16:0/9al-PC has a profound effect on the eicosanoid pathway, which may have implications in inflammatory pulmonary disease states where eicosanoids have been shown to play a role. PMID:27448436

  17. Ozone production potential following convective redistribution of biomass burning emissions

    NASA Technical Reports Server (NTRS)

    Pickering, Kenneth E.; Thompson, Anne M.; Scala, John R.; Tao, Wei-Kuo; Simpson, Joanne

    1992-01-01

    The effects of deep convection on the potential for forming ozone in the free troposphere have been simulated for regions where the trace gas composition is influenced by biomass burning. Cloud photochemical and dynamic simulations based on observations in the 1980 and 1985 Brazilian campaigns form the basis of a sensitivity study of the ozone production potential under differing conditions. It is seen that there is considerably more ozone formed in the middle and upper troposphere when convection has redistributed hydrocarbons, NO(x), and CO compared to the example of no convection.

  18. New Directions: Ozone-initiated reaction products indoors may be more harmful than ozone itself

    NASA Astrophysics Data System (ADS)

    Weschler, Charles J.

    2004-10-01

    Epidemiological studies have found associations between ozone concentrations measured at outdoor monitoring stations and certain adverse health outcomes. As a recent example, Gent et al. (2003, Journal of the American Medical Association 290, 1859-1867) have observed an association between ozone levels and respiratory symptoms as well as the use of maintenance medication by 271 asthmatic children living in Connecticut and the Springfield area of Massachusetts. In another example, Gilliland et al. (2001, Epidemiology 12, 43-54) detected an association between short-term increases in ozone levels and increased absences among 4th grade students from 12 southern California communities during the period from January to June 1996. Although children may spend a significant amount of time outdoors, especially during periods when ozone levels are elevated, they spend a much larger fraction of their time indoors. I hypothesize that exposure to the products of ozone-initiated indoor chemistry is more directly responsible for the health effects observed in the cited epidemiological studies than is exposure to outdoor ozone itself.

  19. Ozone

    SciTech Connect

    Not Available

    1988-06-01

    The author discusses the debate over whether concern about a hole in the ozone layer in Antarctic is real or science fiction. There is a growing consensus that efforts must be taken to protect the ozone layer. The issue now is not whether chlorofluorocarbons (CFCs) should be controlled and regulated but how much and how soon. The United States has urged that the production of dangerous CFCs, and any other chemicals that affect the ozone layer, be restricted immediately to current levels and that their use be reduced 95 percent over the next decade. The American position was too strong for many European nations and the Japanese. Negotiations at an international conference on the matter broke down. The breakdown is due in part to a more acute concern for environmental matters in the United States than exists in many countries. Meanwhile CFCs are linked to another environmental problem that equally threatens the world - the Greenhouse Effect. The earth is in a natural warming period, but man could be causing it to become even warmer. The Greenhouse Effect could have a catastrophic impact on mankind, although nothing has been proven yet.

  20. Ozonation of anilines: Kinetics, stoichiometry, product identification and elucidation of pathways.

    PubMed

    Tekle-Röttering, Agnes; von Sonntag, Clemens; Reisz, Erika; Eyser, Claudia Vom; Lutze, Holger V; Türk, Jochen; Naumov, Sergej; Schmidt, Winfried; Schmidt, Torsten C

    2016-07-01

    Anilines as archetypes for aromatic amines, which play an important role in the production of, e.g., dyestuffs, plastics, pesticides or pharmaceuticals were investigated in their reaction with ozone. Due to their high reactivity towards ozone (1.2 × 10(5)-2.4 × 10(6) M(-1) s(-1)) the investigated aniline bearing different substituents are readily degraded in ozonation. However, around 4 to 5 molecules of ozone are needed to yield a successful transformation of aniline, most likely due to a chain reaction that decomposes ozone without compound degradation. This is inferred from OH radical scavenging experiments, in which compound transformation per ozone consumed is increased. Mechanistic considerations based on product formation indicate that addition to the aromatic ring is the preferential reaction in the case of aniline, p-chloroaniline and p-nitroaniline (high amounts of o-hydroxyaniline, p-hydroxyaniline, chloride, nitrite and nitrate, respectively were found). For aniline an addition to the nitrogen happens but to a small extent, since nitroso- and nitrobenzene were observed as well. In the case of N-methylaniline and N,N-dimethylaniline, an electron transfer reaction from nitrogen to ozone was proven due to the formation of formaldehyde. In contrast, for p-methylaniline and p-methoxyaniline the formation of formaldehyde may result from an electron transfer reaction at the aromatic ring. Additional oxidation pathways for all of the anilines under study are reactions of hydroxyl radicals formed in the electron transfer of ozone with the anilines (OH radical yields = 34-59%). These reactions may form aminyl radicals which in the case of aniline can terminate in bimolecular reactions with other compounds such as the determined o-hydroxyaniline by yielding the detected 2-amino-5-anilino-benzochinon-anil. PMID:27088249

  1. Estimate of ozone production and destruction over northwestern Europe

    NASA Astrophysics Data System (ADS)

    Beck, Jeannette P.; Grennfelt, Peringe

    Ozone data from more than 70 monitoring sites in the European TOR and EMEP networks from 1989 were evaluated. In summer the general spatial pattern showed a gradient in the average diurnal maximum ozone concentration with lower values (30-40 ppb) in the northwestern part and higher concentrations (60-70 ppb) towards the southeastern part of the networks. In winter a decreasing gradient was exhibited from the northwest to the southeast. The current UN-ECE 1-h guide value (75 ppb) for the prevention of vegetation damage was exceeded regularly at nearly all sites; the provisional O 3 exposure limit of 300 ppb.h (product of the residual ozone concentration above a threshold (40 ppb) value and exposure duration) was exceeded at all monitoring sites. An estimate of the European internal production and destruction of ozone was made by analyzing the diurnal variation in ozone at European boundary layer background "reference" sites and "polluted" sites. The assessment led to a summer mean internal production of 10-15 ppb in some areas in central Europe, while during winter an ozone sink was found. A complicating factor in this work proved to be the degree of influence of local factors, e.g. emission of oxides of nitrogen and dry deposition. This study therefore emphasizes the importance of spatial characterization of the monitoring sites.

  2. The Effect of Lightning NOx Production on Surface Ozone in the Continental United States

    NASA Technical Reports Server (NTRS)

    Kaynak, B.; Hu, Y.; Martin, R. V.; Russell, A. G.; Choi, Y.; Wang, Y.

    2008-01-01

    Lightning NO(x) emissions calculated using the US National Lightning Detection Network data were found to account for 30% of the total NO(x) emissions for July August 2004, a period chosen both for having higher lightning NO(x) production and high ozone levels, thus maximizing the likelihood that such emissions could impact peak ozone levels. Including such emissions led to modest, but sometimes significant increases in simulated surface ozone when using the Community Multi-scale Air Quality Model (CMAQ). Three model simulations were performed, two with the addition of lightning NO(x) emissions, and one without. Domain-wide daily maximum 8-h ozone changes due to lightning NO(x) were less than 2 ppbv in 71 % of the cases with a maximum of 10 ppbv; whereas the difference in 1-h ozone was less than 2 ppbv in 77% of the cases with a maximum of 6 ppbv. Daily maximum 1-h and 8-h ozone for grids containing O3 monitoring stations changed slightly, with more than 43% of the cases differing less than 2 ppbv. The greatest differences were 42 ppbv for both 1-h and 8-h O3 , though these tended to be on days of lower ozone. Lightning impacts on the season-wide maximum 1-h and 8-h averaged ozone decreased starting from the 1 st to 4th highest values (an average of 4th highest, 8-h values is used for attainment demonstration in the US). Background ozone values from the y-intercept of O3 versus NO(z) curve were 42.2 and 43.9 ppbv for simulations without and with lightning emissions, respectively. Results from both simulations with lightning NO(x) suggest that while North American lightning production of NO(x) can lead to significant local impacts on a few occasions, they will have a relatively small impact on typical maximum levels and determination of Policy Relevant Background levels.

  3. Effect of Isopropyl Alcohol Addition in Ozonated Water on the Corrosion of Tungsten Film

    NASA Astrophysics Data System (ADS)

    Lee, Younghwan; Lee, June Young; Im, Kyung Taek; Lim, Sangwoo

    2009-05-01

    Acetic acid (HAc) or 2-propanol (IPA) was added to ozonated water vapor, and its ability to clean corroded Al and W surfaces was studied. No changes to the surface morphology or film thickness were observed on any of the Al films to which the ozonated water vapor cleaning process was applied, either with or without the addition of HAc and IPA. No change in the W surface was observed when it was exposed to either pure ozonated water vapor or that which had HAc-added. However, the surface morphology of the W film changed, and its thickness decreased, when it was exposed to the ozonated water vapor with added IPA. It was also noted that no corrosion occurred on the surface of W when only IPA and the water mixture vapor were injected. Given that the pH of the water with added IPA was unchanged, regardless of whether ozone feeding had occurred, it can be concluded that the main reason for the corrosion of the W film is the accelerated oxidation of W. This accelerated oxidation is a byproduct of ozone decomposition in the presence of a radical promoter, rather than the enhanced dissolution of oxidized W.

  4. Development and Application of Hyperspectral Infrared Ozone Retrieval Products for Operational Meteorology

    NASA Technical Reports Server (NTRS)

    Berndt, Emily; Zavodsky, Bradley; Jedlovec, Gary

    2015-01-01

    cyclogenesis and hurricane force wind events. Currently, forecasters at WPC/OPC are evaluating the Air Mass RGB imagery in conjunction with the AIRS total column ozone to aid forecasting cyclogenesis and high wind forecasts. One of the limitations of the total ozone product is that it is difficult for forecasters to determine whether elevated ozone concentrations are related to stratospheric air or climatologically high values of ozone in certain regions. To address this limitation, SPoRT created an AIRS ozone anomaly product which calculates the percent of normal ozone based on a global stratospheric ozone mean climatology. With the knowledge that ozone values 125 percent of normal and greater typically represent stratospheric air; the anomaly product can be used with the total column ozone product to confirm regions of stratospheric air on the Air Mass RGB. This presentation describes the generation of these products along with forecaster feedback concerning the use of the AIRS ozone products in conjunction with the Air Mass RGB product for the unique forecast challenges WPC/OPC face. Additionally examples of CrIS ozone and anomaly products will be shown to further demonstrate the utility and capability of JPSS in forecasting unique events.

  5. Demonstration of AIRS Total Ozone Products to Operations to Enhance User Readiness

    NASA Technical Reports Server (NTRS)

    Berndt, Emily; Zavodsky, Bradley; Jedlovec, Gary

    2014-01-01

    cyclogenesis and hurricane force wind events. Currently, forecasters at WPC/OPC are evaluating the Air Mass RGB imagery in conjunction with the AIRS total column ozone to aid forecasting cyclogenesis and high wind forecasts. One of the limitations of the total ozone product is that it is difficult for forecasters to determine whether elevated ozone concentrations are related to stratospheric air or climatologically high values of ozone in certain regions. To address this limitation, SPoRT created an AIRS ozone anomaly product which calculates the percent of normal ozone based on a global stratospheric ozone mean climatology. With the knowledge that ozone values 125 percent of normal and greater typically represent stratospheric air; the anomaly product can be used with the total column ozone product to confirm regions of stratospheric air on the Air Mass RGB. This presentation describes the generation of these products along with forecaster feedback concerning the use of the AIRS ozone products in conjunction with the Air Mass RGB product for the unique forecast challenges WPC/OPC face. Additionally examples of CrIS ozone and anomaly products will be shown to further demonstrate the utility and capability of JPSS in forecasting unique events.

  6. Ozone

    MedlinePlus

    ... Earth's surface. It shields us from the sun's ultraviolet rays. Part of the good ozone layer is ... enough good ozone, people may get too much ultraviolet radiation. This may increase the risk of skin ...

  7. Ozone

    MedlinePlus

    ... reactive form of oxygen. In the upper atmosphere, ozone forms a protective layer that shields us from the sun’s ultraviolet rays. At ground level, ozone is a harmful air pollutant and a primary ...

  8. Ozone Production In The Upper Troposphere

    NASA Astrophysics Data System (ADS)

    Phillips, G. J.; Actoleicester Team

    A box modelling study has been carried out using data obtained from the UK -NERC funded UTLS-OZONE and EXPORT measurement campaigns. Data from the campaigns was used to constrain the model and the subsequent results were used to calculate ozone tendencies within air mass types encountered. Both average and air mass specific analyses were carried out. These campaigns were conducted during the spring and summer of 2000 respectively, onboard the UKMO C-130 Hercules aircraft. The spring data was taken mainly from the north Atlantic, west of Scotland, and the summer data was collected over central Europe. Five-day back trajectories calculated from ECMWF wind fields by the Universities of Reading and Cambridge were used to separate the data for analysis.

  9. Ozone

    MedlinePlus

    Ozone is a gas. It can be good or bad, depending on where it is. "Good" ozone occurs naturally about 10 to 30 miles above ... the sun's ultraviolet rays. Part of the good ozone layer is gone. Man-made chemicals have destroyed ...

  10. In vitro ozone exposure inhibits mitogen-induced lymphocyte proliferation and IL-2 production

    SciTech Connect

    Becker, S.; Jordan, R.L.; Orlando, G.S.; Koren, H.S.

    1989-01-01

    Human blood mononuclear cells were exposed to ozone in vitro and thereafter analyzed for competence in mitogen-induced proliferation as well as IL-1 and IL-2 production. Proliferative responses induced by phytohemagglutinin (PHA), concanavalin A (Con A), and pokeweed mitogen (PWM) were all depressed in lymphocytes exposed to an ozone concentration of 1 ppm for 4-6 h. The response to PWM was most sensitive to the ozone effect (38% suppression); responses to Con A and PHA were suppressed to a lesser extent, 23% and 18%, respectively, and were not significantly different from each other. PWM responses were affected at an ozone concentration as low as 0.1 ppm; however, no suppression of Con A-induced proliferation was seen below 0.18 ppm or of PHA-induced proliferation below 0.5 ppm. When lymphocytes and monocytes were exposed separately to ozone and then mixed back with control air-exposed monocytes or lymphocytes, both cell types appeared to be affected and the functional defects caused by the pollutant were additive. Monocyte IL-1 production induced by endotoxin was not affected by ozone exposure, while surface expression of HLA-DR on exposed monocytes was reduced by 40% 24 h after exposure. Moreover, lymphocytes exposed to ozone produced 46% less IL-2 while expressing similar surface density of IL-2 receptors. Taken together, these results show that exposure to ozone has distinct adverse effects on lymphocytes and monocytes, both of which are important in local immune defenses in the lung.

  11. The Influence of Atmospheric Conditions on the Production of Ozone during VOC Oxidation

    NASA Astrophysics Data System (ADS)

    Coates, J.; Butler, T. M.

    2015-12-01

    Tropospheric ozone is a short-lived climate forcing pollutant that is detrimental to human health and crop growth. Reactions involving volatile organic compounds (VOC) and nitrogen oxides (NOx) in the presence of sunlight produce ozone. Ozone production is a non-linear function of the concentrations of both NOx and VOC, with VOC acting as the "fuel" for ozone production and NOx as the "catalyst". Different VOC, due to their differing structure and carbon content, have different maximum potential to produce ozone. Due to different degrees of reactivity, VOC also differ in the time taken to reach this maximum ozone production potential under ideal conditions. Ozone production is also influenced by meteorological factors such as radiation, temperature, advection and mixing, which may alter the rate of ozone production, and the degree to which VOC are able to reach their maximum ozone production potential. Identifying the chemical and meteorological processes responsible for controlling the degree to which VOC are able to reach their maximum ozone production potential could inform decisions on emission control to efficiently tackle high levels of tropospheric ozone. In this study we use a boxmodel to determine the chemical processes affecting ozone production under different meteorological and chemical conditions. The chemistry scheme used by the boxmodel is "tagged" for each initial VOC enabling attribution of ozone production to its VOC source. We systematically vary a number of meteorological parameters along with the source of NOx within the box model to simulate a range of atmospheric conditions. These simulations are compared with a control simulation done under conditions of maximum ozone formation to determine which parameters affect the rate at which VOC produce ozone and the extent to which they reach their maximum potential to produce ozone. We perform multi-day simulations in order to examine whether these processes can influence ozone production over

  12. The Transition of Atmospheric Infrared Sounder Total Ozone Products to Operations

    NASA Technical Reports Server (NTRS)

    Berndt, E. B.; Zavodsky, B. T.; Jedlovec, G. J.

    2014-01-01

    The National Aeronautics and Space Administration Short-term Prediction Research and Transition Center (NASA SPoRT) has transitioned a total column ozone product from the Atmospheric Infrared Sounder (AIRS) retrievals to the Weather Prediction Center and Ocean Prediction Center. The total column ozone product is used to diagnose regions of warm, dry, ozone-rich, stratospheric air capable of descending to the surface to create high-impact non-convective winds. Over the past year, forecasters have analyzed the Red, Green, Blue (RGB) Air Mass imagery in conjunction with the AIRS total column ozone to aid high wind forecasts. One of the limitations of the total ozone product is that it is difficult for forecasters to determine whether elevated ozone concentrations are related to stratospheric air or climatologically high values of ozone in certain regions. During the summer of 2013, SPoRT created an AIRS ozone anomaly product which calculates the percent of normal ozone based on a global stratospheric ozone mean climatology. With the knowledge that ozone values 125 percent of normal and greater typically represent stratospheric air; the anomaly product can be used with the total column ozone product to confirm regions of stratospheric air. This paper describes the generation of these products along with forecaster feedback concerning the use of the AIRS ozone products in conjunction with the RGB Air Mass product to access the utility and transition of the products.

  13. Secondary Pollutants from Ozone Reaction with Ventilation Filters and Degradation of Filter Media Additives

    SciTech Connect

    Destaillats, Hugo; Chen, Wenhao; Apte, Michael; Li, Nuan; Spears, Michael; Almosni, Jérémie; Brunner, Gregory; Zhang, Jianshun; Fisk, William J.

    2011-05-01

    Prior research suggests that chemical processes taking place on the surface of particle filters employed in buildings may lead to the formation of harmful secondary byproducts. We investigated ozone reactions with fiberglass, polyester, cotton/polyester and polyolefin filter media, as well as hydrolysis of filter media additives. Studies were carried out on unused media, and on filters that were installed for 3 months in buildings at two different locations in the San Francisco Bay Area. Specimens from each filter media were exposed to {approx}150 ppbv ozone in a flow tube under a constant flow of dry or humidified air (50percent RH). Ozone breakthrough was recorded for each sample over periods of {approx}1000 min; the ozone uptake rate was calculated for an initial transient period and for steady-state conditions. While ozone uptake was observed in all cases, we did not observe significant differences in the uptake rate and capacity for the various types of filter media tested. Most experiments were performed at an airflow rate of 1.3 L/min (face velocity = 0.013 m/s), and a few tests were also run at higher rates (8 to 10 L/min). Formaldehyde and acetaldehyde, two oxidation byproducts, were quantified downstream of each sample. Those aldehydes (m/z 31 and 45) and other volatile byproducts (m/z 57, 59, 61 and 101) were also detected in real-time using Proton-Transfer Reaction - Mass Spectrometry (PTR-MS). Low-ppbv byproduct emissions were consistently higher under humidified air than under dry conditions, and were higher when the filters were loaded with particles, as compared with unused filters. No significant differences were observed when ozone reacted over various types of filter media. Fiberglass filters heavily coated with impaction oil (tackifier) showed higher formaldehyde emissions than other samples. Those emissions were particularly high in the case of used filters, and were observed even in the absence of ozone, suggesting that hydrolysis of additives

  14. Ground-Level Ozone Following Astrophysical Ionizing Radiation Events: An Additional Biological Hazard?

    PubMed

    Thomas, Brian C; Goracke, Byron D

    2016-01-01

    Astrophysical ionizing radiation events such as supernovae, gamma-ray bursts, and solar proton events have been recognized as a potential threat to life on Earth, primarily through depletion of stratospheric ozone and subsequent increase in solar UV radiation at Earth's surface and in the upper levels of the ocean. Other work has also considered the potential impact of nitric acid rainout, concluding that no significant threat is likely. Not yet studied to date is the potential impact of ozone produced in the lower atmosphere following an ionizing radiation event. Ozone is a known irritant to organisms on land and in water and therefore may be a significant additional hazard. Using previously completed atmospheric chemistry modeling, we examined the amount of ozone produced in the lower atmosphere for the case of a gamma-ray burst and found that the values are too small to pose a significant additional threat to the biosphere. These results may be extended to other ionizing radiation events, including supernovae and extreme solar proton events. PMID:26745353

  15. Ozone decreases soybean productivity and water use efficiency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The combination of population growth and climate change will increase pressure on agricultural and water resources throughout this century. An additional consequence of this growth is an increase in anthropogenic emissions that lead to the formation of tropospheric ozone, which in concert with clima...

  16. Ozone production at the National Synchrotron Light Source

    SciTech Connect

    Weilandics, C.; Rohrig, N.; Gmur, N.F.

    1987-01-01

    Ozone production by synchrotron radiation as a function of power density in air was investigated using a white beam at the BNL National Synchrotron Light Source (NSLS) x-ray ring. Power densities were calculated from the energy spectrum at 2.52 GeV. Ozone concentrations in small beam pipes were measured for power densities between I = 10/sup 12/ and 10/sup 15/ eV . cm/sup -3/ . sec/sup -1/. The measured ozone half-life was 37 +- 2 min. The measured G-value was 2.69 +- 0.14 mol/100 eV and the ozone destruction factor k was less than 7 x 10/sup -19/ cm/sup 3/ . eV/sup -1/. The random uncertainties stated are approximately one standard error. The large departure of the values for G and k from previous values suggest that some undiscovered systematic error may exist in the experiment. Ozone concentration in excess of the 0.1 ppM ACGIH TLV can be generated in the experimental hutches but can readily be controlled. Industrial hygiene aspects of operation and possible control measures will be discussed. 19 refs., 7 figs., 3 tabs.

  17. Validation of SCIAMACHY Radiances and Ozone Products Using Ground and Space Observations

    NASA Technical Reports Server (NTRS)

    Hilsenrath, E.; Bhartia, P. K.; Bojkov, B. R.; Kowalewski, M.; Labow, G.; Ahmad, Z.

    2004-01-01

    Validation of SCIAMACHY data products are is key element for the detecting a stratospheric ozone recovery, which is a high priority for environmental research and environmental policy. Models predict an ozone recovery at a much lower rate than the measured depletion rate observed to date. Therefore improved precision of the satellite and ground ozone observing systems are required over the long term to verify its recovery. We show that validation of satellite radiances from space and from the ground can be an effective means for correcting long term drifts of backscatter type satellite measurements such as SCIAMACHY and can be used to cross calibrate all BUV instruments in orbit (TOMS, SBUV/2, GOME, OMI, GOME-2, OMPS). This method bypasses the retrieval algorithms used for both satellite and ground based measurements that are normally used to validate and correct the satellite data. This approach however requires well calibrated instruments and an accurate radiative transfer model that accounts for aerosols. In addition to comparing radiances, validation of SCIAMACHY ozone products will conducted by comparing total and profile ozone with TOMS and SBUV/2.

  18. 40 CFR 82.18 - Availability of production in addition to baseline production allowances for class II controlled...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 18 2013-07-01 2013-07-01 false Availability of production in addition to baseline production allowances for class II controlled substances. 82.18 Section 82.18 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Production and...

  19. 40 CFR 82.18 - Availability of production in addition to baseline production allowances for class II controlled...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 false Availability of production in addition to baseline production allowances for class II controlled substances. 82.18 Section 82.18 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Production and...

  20. 40 CFR 82.9 - Availability of production allowances in addition to baseline production allowances for class I...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 false Availability of production allowances in addition to baseline production allowances for class I controlled substances. 82.9 Section 82.9 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Production...

  1. 40 CFR 82.9 - Availability of production allowances in addition to baseline production allowances for class I...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 18 2013-07-01 2013-07-01 false Availability of production allowances in addition to baseline production allowances for class I controlled substances. 82.9 Section 82.9 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Production...

  2. Influence of the heterogeneous reaction HCL + HOCl on an ozone hole model with hydrocarbon additions

    SciTech Connect

    Elliott, S.; Cicerone, R.J.; Turco, R.P.

    1994-02-20

    Injection of ethane or propane has been suggested as a means for reducing ozone loss within the Antarctic vortex because alkanes can convert active chlorine radicals into hydrochloric acid. In kinetic models of vortex chemistry including as heterogeneous processes only the hydrolysis and HCl reactions of ClONO{sub 2} and N{sub 2}O{sub 5}, parts per billion by volume levels of the light alkanes counteract ozone depletion by sequestering chlorine atoms. Introduction of the surface reaction of HCl with HOCl causes ethane to deepen baseline ozone holes and generally works to impede any mitigation by hydrocarbons. The increased depletion occurs because HCl + HOCl can be driven by HO{sub x} radicals released during organic oxidation. Following initial hydrogen abstraction by chlorine, alkane breakdown leads to a net hydrochloric acid activation as the remaining hydrogen atoms enter the photochemical system. Lowering the rate constant for reactions of organic peroxy radicals with ClO to 10{sup {minus}13} cm{sup 3} molecule{sup {minus}1} s{sup {minus}1} does not alter results, and the major conclusions are insensitive to the timing of the ethane additions. Ignoring the organic peroxy radical plus ClO reactions entirely restores remediation capabilities by allowing HO{sub x} removal independent of HCl. Remediation also returns if early evaporation of polar stratospheric clouds leaves hydrogen atoms trapped in aldehyde intermediates, but real ozone losses are small in such cases. 95 refs., 4 figs., 7 tabs.

  3. Removal of Disinfection By-Products from Contaminated Water Using a Synthetic Goethite Catalyst via Catalytic Ozonation and a Biofiltration System·

    PubMed Central

    Wang, Yu-Hsiang; Chen, Kuan-Chung

    2014-01-01

    The effects of synthetic goethite (α-FeOOH) used as the catalyst in catalytic ozonation for the degradation of disinfection by-product (DBP) precursors are investigated. A biofiltration column applied following the catalytic ozonation process is used to evaluate the efficiency of removing DBP precursors via biotreatment. Ozone can rapidly react with aromatic compounds and oxidize organic compounds, resulting in a decrease in the fluorescence intensity of dissolved organic matter (DOM). In addition, catalytic ozonation can break down large organic molecules, which causes a blue shift in the emission-excitation matrix spectra. Water treated with catalytic ozonation is composed of low-molecular structures, including soluble microbial products (SMPs) and other aromatic proteins (APs). The DOM in SMPs and APs is removed by subsequent biofiltration. Catalytic ozonation has a higher removal efficiency for dissolved organic carbon and higher ultraviolet absorbance at 254 nm compared to those of ozonation without a catalyst. The use of catalytic ozonation and subsequent biofiltration leads to a lower DBP formation potential during chlorination compared to that obtained using ozonation and catalytic ozonation alone. Regarding DBP species during chlorination, the bromine incorporation factor (BIF) of trihalomethanes and haloacetic acids increases with increasing catalyst dosage in catalytic ozonation. Moreover, the highest BIF is obtained for catalytic ozonation and subsequent biofiltration. PMID:25211774

  4. Tropical Tropospheric Ozone from SHADOZ (Southern Hemisphere ADditional Ozonesondes) Network: A Project for Satellite Research, Process Studies, Education

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Witte, Jacquelyn C.; Oltmans, Samuel J.; Schmidlin, Francis J.; Coetzee, G. J. R.; Hoegger, Bruno; Kirchhoff, V. W. J. H.; Ogawa, Toshihiro; Kawakami, Shuji; Posny, Francoise

    2002-01-01

    The first climatological overview of total, stratospheric and tropospheric ozone in the southern hemisphere tropical and subtropics is based on ozone sounding data from 10 sites comprising the Southern Hemisphere Additional OZonesondes (SHADOZ) network. The period covered is 1998-2000. Observations were made over: Ascension Island; Nairobi, Kenya; Irene, South Africa; Reunion Island; Watukosek, Java; Fiji; Tahiti; American Samoa; San Cristobal, Galapagos; Natal, Brazil. Campaign data were collected on a trans-Atlantic oceanographic cruise and during SAFARI-2000 in Zambia. The ozone data, with simultaneous temperature profiles to approx. 7 hPa and relative humidity to approx. 200 hPa, reside at: . SHADOZ ozone time-series and profiles give a perspective on tropical total, stratospheric and tropospheric ozone. Prominent features are highly variable tropospheric ozone and a zonal wave-one pattern in total (and tropospheric) column ozone. Total, stratospheric and tropospheric column ozone amounts peak between August and November and are lowest between March and May. Tropospheric ozone variability over the Indian and Pacific Ocean displays influences of the Indian Ocean Dipole and convective mixing. Pollution transport from Africa and South America is a seasonal feature. Tropospheric ozone seasonality over the Atlantic Basin shows effects of regional subsidence and recirculation as well as biomass burning. Dynamical and chemical influences appear to be of comparable magnitude though model studies are needed to quantify this.

  5. Insights into Tropical Tropospheric Ozone from the 1998-2000 SHADOZ (Southern Hemisphere Additional Ozonesondes) Data Record

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Witte, Jacquelyn C.; Oltmans, Samuel J.; Schmidlin, Francis J.; Volker, W.; Kirchhoff, J. H.; Posny, Franaoise; Gert, J.; Coetzee, R.; Hoegger, Bruno; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    We describe the first overview of total, stratospheric and tropospheric ozone in the southern hemisphere tropics based on a three year, ten site record of ozone soundings from the Southern Hemisphere Additional Ozonesondes (SHADOZ) network. Observations covering 1998-2000 were made over Ascension Island; Nairobi, Kenya; Irene, South Africa; Reunion Island; Watukosek, Java; Fiji; Tahiti; American Samoa; San Cristobal, Galapagos; Natal, Brazil. The ozone data, with simultaneous temperature profiles to approximately 7 hPa and relative humidity to approximately 200 hPa, are at an archive: http://code9l6. gsfc.nasa.gov/Data_services/shadoz. Prominent features are highly variable tropospheric ozone, a zonal wave-one pattern in total (and tropospheric) column ozone, and signatures of the Quasi-Biennial Oscillation (QBO) in stratospheric ozone. Total, stratospheric and tropospheric column ozone amounts usually peak between August and November and are lowest in the first half of the year. Tropospheric ozone variability over the Indian and Pacific Ocean displays influences of the waning 1997-1998 Indian Ocean Dipole and ENSO (El Nino / Southern Oscillation), seasonal convection and pollution transport from Africa. Tropospheric ozone over the Atlantic Basin reflects regional subsidence and recirculation as well as pollution ozone from biomass burning.

  6. Diagnosis of Photochemical Ozone Production Rates and Limiting Factors based on Observation-based Modeling Approach over East Asia: Impact of Radical Chemistry Mechanism and Ozone-Control Implications

    NASA Astrophysics Data System (ADS)

    Kanaya, Y.

    2015-12-01

    Growth of tropospheric ozone, causing health and climate impacts, is concerned over East Asia, because emissions of precursors have dramatically increased. Photochemical production rates of ozone and limiting factors, primarily studied for urban locations, have been poorly assessed within a perspective of regional-scale air pollution over East Asia. We performed comprehensive observations of ozone precursors at several locations with regional representativeness and made such assessment based on the observation-based modeling approach. Here, diagnosis at Fukue Island (32.75°N, 128.68°E) remotely located in western Japan (May 2009) is highlighted, where the highest 10% of hourly ozone concentrations reached 72‒118 ppb during May influenced by Asian continental outflow. The average in-situ ozone production rate was estimated to be 6.8 ppb per day, suggesting that in-travel production was still active, while larger buildup must have occurred beforehand. Information on the chemical status of the air mass arriving in Japan is important, because it affects how further ozone production occurs after precursor addition from Japanese domestic emissions. The main limiting factor of ozone production was usually NOx, suggesting that domestic NOx emission control is important in reducing further ozone production and the incidence of warning issuance (>120 ppb). VOCs also increased the ozone production rate, and occasionally (14% of time) became dominant. This analysis implies that the VOC reduction legislation recently enacted should be effective. The uncertainty in the radical chemistry mechanism governing ozone production had a non-negligible impact, but the main conclusion relevant to policy was not altered. When chain termination was augmented by HO2-H2O + NO/NO2 reactions and by heterogeneous loss of HO2 on aerosol particle surfaces, the daily ozone production rate decreased by <24%, and the fraction of hours when the VOC-limited condition occurred varied from 14% to 13

  7. Southern Hemisphere Additional Ozonesondes (SHADOZ) 1998-2000 tropical ozone climatology 1. Comparison with Total Ozone Mapping Spectrometer (TOMS) and ground-based measurements

    NASA Astrophysics Data System (ADS)

    Thompson, Anne M.; Witte, Jacquelyn C.; McPeters, Richard D.; Oltmans, Samuel J.; Schmidlin, Francis J.; Logan, Jennifer A.; Fujiwara, Masatomo; Kirchhoff, Volker W. J. H.; Posny, FrançOise; Coetzee, Gert J. R.; Hoegger, Bruno; Kawakami, Shuji; Ogawa, Toshihiro; Johnson, Bryan J.; VöMel, Holger; Labow, Gordon

    2003-01-01

    A network of 10 southern hemisphere tropical and subtropical stations, designated the Southern Hemisphere Additional Ozonesondes (SHADOZ) project and established from operational sites, provided over 1000 ozone profiles during the period 1998-2000. Balloon-borne electrochemical concentration cell (ECC) ozonesondes, combined with standard radiosondes for pressure, temperature, and relative humidity measurements, collected profiles in the troposphere and lower to midstratosphere at: Ascension Island; Nairobi, Kenya; Irene, South Africa; Réunion Island; Watukosek, Java; Fiji; Tahiti; American Samoa; San Cristóbal, Galapagos; and Natal, Brazil. The archived data are available at: . In this paper, uncertainties and accuracies within the SHADOZ ozone data set are evaluated by analyzing: (1) imprecisions in profiles and in methods of extrapolating ozone above balloon burst; (2) comparisons of column-integrated total ozone from sondes with total ozone from the Earth-Probe/Total Ozone Mapping Spectrometer (TOMS) satellite and ground-based instruments; and (3) possible biases from station to station due to variations in ozonesonde characteristics. The key results are the following: (1) Ozonesonde precision is 5%. (2) Integrated total ozone column amounts from the sondes are usually to within 5% of independent measurements from ground-based instruments at five SHADOZ sites and overpass measurements from the TOMS satellite (version 7 data). (3) Systematic variations in TOMS-sonde offsets and in ground-based-sonde offsets from station to station reflect biases in sonde technique as well as in satellite retrieval. Discrepancies are present in both stratospheric and tropospheric ozone. (4) There is evidence for a zonal wave-one pattern in total and tropospheric ozone, but not in stratospheric ozone.

  8. Oxidation of aminodinitrotoluenes with ozone: Products and pathways

    SciTech Connect

    Spanggord, R.J.; Yao, C.D.; Mill, T.

    2000-02-01

    Aminodinitrotoluenes [2-amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT)] are environmental pollutants that arise from the microbial biotransformation of 2,4,6-trinitrotoluene (TNT). These chemicals are unique to soils, lagoons, and groundwaters near TNT production and handling facilities. In the remediation of such environments, consideration must be given to the behavior of these pollutants toward the remediation technology. An investigation of the products from the reaction of ozone with aminodinitrotoluenes (ADNTs) provides information about the oxidation pathway. Studies conducted at low conversions of 2- and 4-ADNT show 2:1 ozone/ADNT stoichiometries, prompt formation of glyoxylic and pyruvic acids, and NO{sub 2}{sup {minus}} and NO{sub 3}{sup {minus}} (NO{sub x}) ions. Reaction schemes to account for these results involve a 1,3-dipolar cycloaddition of ozone to selected double bonds of the aromatic ring, leading to ring cleavage. {sup 15}N-Labeling experiments indicate that the amino function is not involved in the initial ozone oxidation and eventually is incorporated into pyruvamide (2-ADNT) and oxamic acid (4-ADNT) before being oxidized to nitrate.

  9. Quantifying VOC-Reaction Tracers, Ozone Production, and Continuing Aerosol Production Rates in Urban and Far-Downwind Atmospheres

    NASA Technical Reports Server (NTRS)

    Chatfield, Robert; Ren, X.; Brune, W.; Fried, A.; Schwab, J.

    2008-01-01

    We have found a surprisingly informative decomposition of the complex question of smoggy ozone production (basically, [HO2] in a more locally determined field of [NO]) in the process of linked investigations of modestly smoggy Eastern North America (by NASA aircraft, July 2004) and rather polluted Flushing, NYC (Queens College, July, 2001). In both rural and very polluted situations, we find that a simple contour graph parameterization of the local principal ozone production rate can be estimated using only the variables [NO] and j(sub rads) [HCHO]: Po(O3) = c (j(sub rads) [HCHO])(sup a) [HCHO](sup b). Here j(sub rads) is the photolysis of HCHO to radicals, presumably capturing many harder-UV photolytic processes and the principle ozone production is that due to HO2; mechanisms suggest that ozone production due to RO2 is closely correlated, often suggesting a limited range of different proportionality factors. The method immediately suggests a local interpretation for concepts of VOC limitation and NOx limitation. We believe that the product j(sub rads) [HCHO] guages the oxidation rate of observed VOC mixtures in a way that also provides [HO2] useful for the principle ozone production rate k [HO2] [NO], and indeed, all ozone chemical production. The success of the method suggests that dominant urban primary-HCHO sources may transition to secondary plume-HCHO sources in a convenient way. Are there other, simple, near-terminal oxidized VOC's which help guage ozone production and aerosol particle formation? Regarding particles, we report on, to the extent NASA Research resources allow, on appealing relationships between far-downwind (Atlantic PBL) HCHO and very fine aerosol (including sulfate. Since j(sub rads) [HCHO] provides a time-scale, we may understand distant-plume particle production in a more quantitative manner. Additionally we report on a statistical search in the nearer field for relationships between glyoxals (important near-terminal aromatic and isoprene

  10. Effects of ozone on productivity and diversity of an early successional forest community

    SciTech Connect

    Barbo, D.N.; Chappelka, A.H.

    1995-12-31

    Little research exists on the effects of tropospheric ozone on the diversity and productivity of native understory vegetation and tree species growing in competition. To address this question, open-top chambers were utilized at a field site in Auburn, Alabama. After completion of a study in 1990, no weed removal, cutting or chemical treatments were allowed in the chambers. Major species include blackberry, andropogan, bahia grass and two species of blackberry, andropogan, bahia grass and two species of panicum grass. In the winter of 1993-1994, after leaf fall, all vegetation was cut to groundline and left as litter. Vegetation was allowed to regenerate naturally the following spring. In addition 5, one-year-old loblolly pines were planted in each chamber in January, 1994. Four treatments, blocked 4 times were used: carbon-filtered air, non-filtered (ambient air), ambient (no plastics) and twice ambient ozone concentrations. Trees were measured monthly for height and diameter. Abundance and frequency of species, and percent ground cover of understory vegetation were calculated. First year results show a decrease in species diversity with increasing ozone concentrations. Percent cover, however, was greatest in the chambers receiving the lowest and highest ozone exposures. Blackberry was the dominate species in the 2 X-ambient ozone treatments. Loblolly pine growth appeared suppressed in the carbon-filtered chambers due to intense competition from understory vegetation. This study will continue for at least one more growing season.

  11. Ozone Production Efficiency in the Baltimore-Washington Urban Plume

    NASA Astrophysics Data System (ADS)

    Hembeck, L.; Vinciguerra, T.; Carpenter, S. F.; Loughner, C.; Canty, T. P.; Weinheimer, A. J.; Cohen, R. C.; Wisthaler, A.; Fried, A.; Pickering, K. E.; Crawford, J. H.; Dickerson, R. R.; Salawitch, R. J.

    2014-12-01

    Elevated levels of tropospheric ozone caused by its precursor emissions of NOx and VOCs have a negative impact on human health and crops. Informed regulatory decisions on how to reduce surface ozone in the Baltimore-Washington region can be made with a thorough understanding of urban plume chemistry and climate. The ozone production efficiency (OPE), which is based on the observed ratio of O3 and various nitrogen species, provides a mechanism for quantitatively assessing air quality representation of a key component of the photochemical evolution of urban plumes. We investigate the representation of ozone precursors within the CMAQ (Community Multi-scale Air Quality) air quality model, with a focus on assessing how well the model represents NOx and HOx chemistry. A comprehensive set of atmospheric observations for which OPE can be found and HO2 and RO2can be inferred, is available from NASA's DISCOVER-AQ campaign for July 2011 in the Baltimore-Washington region. Preliminary results show that the OPE as well as the NOx/NOy ratio in the Baltimore-Washington region derived from measurements is twice as high as within CMAQ, and that isoprene and formaldehyde are too low within CMAQ. Implications for policy will be briefly discussed.

  12. A Multi-sensor Upper Tropospheric Ozone Product (MUTOP) based on TES ozone and GOES water vapor: derivation

    NASA Astrophysics Data System (ADS)

    Felker, S. R.; Moody, J. L.; Wimmers, A. J.; Osterman, G.; Bowman, K.

    2010-12-01

    The Tropospheric Emission Spectrometer (TES), a hyperspectral infrared instrument on the Aura satellite, retrieves a vertical profile of tropospheric ozone. However, polar-orbiting instruments like TES provide limited nadir-view coverage. This work illustrates the value of these observations when taken in context with information about synoptic-scale weather patterns. The goal of this study is to create map-view products of upper troposphere (UT) ozone through the integration of TES ozone measurements with two synoptic dynamical tracers of stratospheric influence: specific humidity derived from the GOES Imager, and potential vorticity from an operational forecast model. As a mixing zone between tropospheric and stratospheric reservoirs, the upper troposphere (UT) exhibits a complex chemical makeup. Determination of ozone mixing ratios in this layer is especially difficult without direct in-situ measurement. However, it is well understood that UT ozone is correlated with dynamical tracers like low specific humidity and high potential vorticity. Blending the advantages of two remotely sensed quantities (GOES water vapor and TES ozone) is at the core of the Multi-sensor Upper Tropospheric Ozone Product (MUTOP). Our approach results in the temporal and spatial coverage of a geostationary platform, a major improvement over individual polar overpasses, while retaining TES's ability to characterize UT ozone. Results suggest that over 70% of TES-observed UT ozone variability can be explained by correlation with the two dynamical tracers. MUTOP reproduces TES retrievals across the GOES-West domain with a root mean square error (RMSE) of 19.2 ppbv. There are several advantages to this multi-sensor derived product approach: (1) it is calculated from 2 operational fields (GOES specific humidity and GFS PV), so the layer-average ozone can be created and used in near real-time; (2) the product provides the spatial resolution and coverage of a geostationary platform as it depicts

  13. Southern Hemisphere Additional Ozonesondes (SHADOZ) 1998-2000 tropical ozone climatology 2. Tropospheric variability and the zonal wave-one

    NASA Astrophysics Data System (ADS)

    Thompson, Anne M.; Witte, Jacquelyn C.; Oltmans, Samuel J.; Schmidlin, Francis J.; Logan, Jennifer A.; Fujiwara, Masatomo; Kirchhoff, Volker W. J. H.; Posny, FrançOise; Coetzee, Gert J. R.; Hoegger, Bruno; Kawakami, Shuji; Ogawa, Toshihiro; Fortuin, J. P. F.; Kelder, H. M.

    2003-01-01

    The first view of stratospheric and tropospheric ozone variability in the Southern Hemisphere tropics is provided by a 3-year record of ozone soundings from the Southern Hemisphere Additional Ozonesondes (SHADOZ) network (http://croc.gsfc.nasa.gov/shadoz). Observations covering 1998-2000 were made over Ascension Island, Nairobi (Kenya), Irene (South Africa), Réunion Island, Watukosek (Java), Fiji, Tahiti, American Samoa, San Cristóbal (Galapagos), and Natal (Brazil). Total, stratospheric, and tropospheric column ozone amounts usually peak between August and November. Other features are a persistent zonal wave-one pattern in total column ozone and signatures of the quasi-biennial oscillation (QBO) in stratospheric ozone. The wave-one is due to a greater concentration of free tropospheric ozone over the tropical Atlantic than the Pacific and appears to be associated with tropical general circulation and seasonal pollution from biomass burning. Tropospheric ozone over the Indian and Pacific Oceans displays influences of the waning 1997-1998 El Niño, seasonal convection, and pollution transport from Africa. The most distinctive feature of SHADOZ tropospheric ozone is variability in the data, e.g., a factor of 3 in column amount at 8 of 10 stations. Seasonal and monthly means may not be robust quantities because statistics are frequently not Gaussian even at sites that are always in tropical air. Models and satellite retrievals should be evaluated on their capability for reproducing tropospheric variability and fine structure. A 1999-2000 ozone record from Paramaribo, Surinam (6°N, 55°W) (also in SHADOZ) shows a marked contrast to southern tropical ozone because Surinam is often north of the Intertropical Convergence Zone (ITCZ). A more representative tropospheric ozone climatology for models and satellite retrievals requires additional Northern Hemisphere tropical data.

  14. A multi-sensor upper tropospheric ozone product (MUTOP) based on TES Ozone and GOES water vapor: derivation

    NASA Astrophysics Data System (ADS)

    Felker, S. R.; Moody, J. L.; Wimmers, A. J.; Osterman, G.; Bowman, K.

    2011-07-01

    The Tropospheric Emission Spectrometer (TES), a hyperspectral infrared instrument on the Aura satellite, retrieves a vertical profile of tropospheric ozone. However, polar-orbiting instruments like TES provide limited nadir-view coverage. This work illustrates the value of these observations when taken in context with geostationary imagery describing synoptic-scale weather patterns. The goal of this study is to create map-view products of upper troposphere (UT) ozone through the integration of TES ozone measurements with two synoptic dynamic tracers of stratospheric influence: specific humidity derived from the GOES Imager water vapor absorption channel, and potential vorticity (PV) from an operational forecast model. As a mixing zone between tropospheric and stratospheric reservoirs, the upper troposphere (UT) exhibits a complex chemical makeup. Determination of ozone mixing ratios in this layer is especially difficult without direct in situ measurement. However, it is well understood that UT ozone is correlated with dynamical tracers like low specific humidity and high potential vorticity. Blending the advantages of two remotely sensed quantities (GOES water vapor and TES ozone) is at the core of the Multi-sensor Upper Tropospheric Ozone Product (MUTOP). Our results suggest that 72 % of TES-observed UT ozone variability can be explained by its correlation with dry air and high PV. MUTOP reproduces TES retrievals across the GOES-West domain with a root mean square error (RMSE) of 18 ppbv (part per billion by volume). There are several advantages to this multi-sensor derived product approach: (1) it is calculated from two operational fields (GOES specific humidity and GFS PV), so maps of layer-average ozone can be created and used in near real-time; (2) the product provides the spatial resolution and coverage of a geostationary image as it depicts the variable distribution of ozone in the UT; and (3) the 6 h temporal resolution of the derived product imagery allows

  15. Rapid Removal of Tetrabromobisphenol A by Ozonation in Water: Oxidation Products, Reaction Pathways and Toxicity Assessment.

    PubMed

    Qu, Ruijuan; Feng, Mingbao; Wang, Xinghao; Huang, Qingguo; Lu, Junhe; Wang, Liansheng; Wang, Zunyao

    2015-01-01

    Tetrabromobisphenol A (TBBPA) is one of the most widely used brominated flame retardants and has attracted more and more attention. In this work, the parent TBBPA with an initial concentration of 100 mg/L was completely removed after 6 min of ozonation at pH 8.0, and alkaline conditions favored a more rapid removal than acidic and neutral conditions. The presence of typical anions and humic acid did not significantly affect the degradation of TBBPA. The quenching test using isopropanol indicated that direct ozone oxidation played a dominant role during this process. Seventeen reaction intermediates and products were identified using an electrospray time-of-flight mass spectrometer. Notably, the generation of 2,4,6-tribromophenol was first observed in the degradation process of TBBPA. The evolution of reaction products showed that ozonation is an efficient treatment for removal of both TBBPA and intermediates. Sequential transformation of organic bromine to bromide and bromate was confirmed by ion chromatography analysis. Two primary reaction pathways that involve cleavage of central carbon atom and benzene ring cleavage concomitant with debromination were thus proposed and further justified by calculations of frontier electron densities. Furthermore, the total organic carbon data suggested a low mineralization rate, even after the complete removal of TBBPA. Meanwhile, the acute aqueous toxicity of reaction solutions to Photobacterium Phosphoreum and Daphnia magna was rapidly decreased during ozonation. In addition, no obvious difference in the attenuation of TBBPA was found by ozone oxidation using different water matrices, and the effectiveness in natural waters further demonstrates that ozonation can be adopted as a promising technique to treat TBBPA-contaminated waters. PMID:26430733

  16. Rapid Removal of Tetrabromobisphenol A by Ozonation in Water: Oxidation Products, Reaction Pathways and Toxicity Assessment

    PubMed Central

    Wang, Xinghao; Huang, Qingguo; Lu, Junhe; Wang, Liansheng; Wang, Zunyao

    2015-01-01

    Tetrabromobisphenol A (TBBPA) is one of the most widely used brominated flame retardants and has attracted more and more attention. In this work, the parent TBBPA with an initial concentration of 100 mg/L was completely removed after 6 min of ozonation at pH 8.0, and alkaline conditions favored a more rapid removal than acidic and neutral conditions. The presence of typical anions and humic acid did not significantly affect the degradation of TBBPA. The quenching test using isopropanol indicated that direct ozone oxidation played a dominant role during this process. Seventeen reaction intermediates and products were identified using an electrospray time-of-flight mass spectrometer. Notably, the generation of 2,4,6-tribromophenol was first observed in the degradation process of TBBPA. The evolution of reaction products showed that ozonation is an efficient treatment for removal of both TBBPA and intermediates. Sequential transformation of organic bromine to bromide and bromate was confirmed by ion chromatography analysis. Two primary reaction pathways that involve cleavage of central carbon atom and benzene ring cleavage concomitant with debromination were thus proposed and further justified by calculations of frontier electron densities. Furthermore, the total organic carbon data suggested a low mineralization rate, even after the complete removal of TBBPA. Meanwhile, the acute aqueous toxicity of reaction solutions to Photobacterium Phosphoreum and Daphnia magna was rapidly decreased during ozonation. In addition, no obvious difference in the attenuation of TBBPA was found by ozone oxidation using different water matrices, and the effectiveness in natural waters further demonstrates that ozonation can be adopted as a promising technique to treat TBBPA-contaminated waters. PMID:26430733

  17. SHADOZ (Southern Hemisphere ADditional Ozonesondes): A Look at the First Three Years' (1998-2000) Tropospheric Ozone Data

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Bhartia, Pawan K. (Technical Monitor)

    2001-01-01

    The first climatological overview of total, stratospheric and tropospheric ozone in the southern hemisphere tropical and subtropics is based on ozone sounding data from 10 sites comprising the Southern Hemisphere ADditional OZonesondes (SHADOZ) network. The period covered is 1998-2000. Observations were made over: Ascension Island; Nairobi, Kenya; Irene, South Africa; RCunion Island; Watukosek, Java; Fiji; Tahiti; American Samoa; San Cristobal, Galapagos; Natai, Brazil. Campaign data were collected on a trans-Atlantic oceanographic cruise and during SAFARI-2000 in Zambia. The ozone data, with simultaneous temperature profiles to approx. 7 hPa and relative humidity to approx. 200 hPa, reside at an open archive: . SHADOZ ozone time-series and profiles give a perspective on tropical total, stratospheric and tropospheric ozone in 1998-2000. Prominent features are highly variable tropospheric ozone, a zonal wave-one pattern in total (and tropospheric) column ozone, and signatures of the Quasi-Biennial Oscillation (QBO) in stratospheric ozone. Total, stratospheric and tropospheric column ozone amounts peak between August and November and are lowest between March and May. Tropospheric ozone variability over the Indian and Pacific Ocean displays influences of the Indian Ocean Dipole, ENSO, and Madden-Julian circulation on convective mixing. Pollution transport from Africa, South American and the Maritime Continent is a seasonal feature. Tropospheric ozone seasonality over the Atlantic Basin shows effects of regional subsidence and recirculation as well as biomass burning. Dynamical and chemical influences appear to be of comparable magnitude.

  18. The 1998-2000 SHADOZ (Southern Hemisphere ADditional OZonesondes) Tropical Ozone Climatology. 2; Stratospheric and Tropospheric Ozone Variability and the Zonal Wave-One

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Witte, Jacquelyn C.; Oltmans, Samuel J.; Schmidlin, Francis J.; Logan, Jennifer A.; Fujiwara, Masatomo; Kirchhoff, Volker W. J. H.; Posny, Francoise; Coetzee, Gert J. R.; Hoegger, Bruno; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    This is the second 'reference' or 'archival' paper for the SHADOZ (Southern Hemisphere Additional Ozonesondes) network and is a follow-on to the recently accepted paper with similar first part of title. The latter paper compared SHADOZ total ozone with satellite and ground-based instruments and showed that the equatorial wave-one in total ozone is in the troposphere. The current paper presents details of the wave-one structure and the first overview of tropospheric ozone variability over the southern Atlantic, Pacific and Indian Ocean basins. The principal new result is that signals of climate effects, convection and offsets between biomass burning seasonality and tropospheric ozone maxima suggest that dynamical factors are perhaps more important than pollution in determining the tropical distribution of tropospheric ozone. The SHADOZ data at () are setting records in website visits and are the first time that the zonal view of tropical ozone structure has been recorded - thanks to the distribution of the 10 sites that make up this validation network.

  19. Discoveries about Tropical Tropospheric Ozone from Satellite and SHADOZ (Southern Hemisphere Additional Ozonesondes) and a Future Perspective on NASA's Ozone Sensors

    NASA Technical Reports Server (NTRS)

    Thompson, Anne

    2003-01-01

    We have been producing near-real tropical tropospheric ozone ('TTO') data from TOMS since 1997 with Prof. Hudson and students at the University of Maryland. Maps for 1996-2000 for the operational Earth-Probe instrument reside at: . We also have archived 'TTO' data from the Nimbus 7/TOMS satellite (1979-1992). The tropics is a region strongly influenced by natural variability and anthropogenic activity and the satellite data have been used to track biomass burning pollution and to detect interannual variability and climate signals in ozone. We look forward to future ozone sensors from NASA; four will be launched in 2004 as part of the EOS AURA Mission. The satellite view of chemical-dynamical interactions in tropospheric ozone is not adequate to capture vertical variability. Thus, in 1998, NASA's Goddard Space Flight Center, NOAA's Climate Monitoring and Diagnostics Laboratory (CMDL) and a team of international sponsors established the SHADOZ (Southern Hemisphere ADditional OZonesondes) project to address the gap in tropical ozone soundings. SHADOZ augments launches at selected sites and provides a public archive of ozonesonde data from twelve tropical and subtropical stations at http://croc.nsfc.nasa.gov/shadoz. The stations are: Ascension Island; Nairobi, Kenya; Irene, South Africa; R,union Island; Watukosek, Java; Fiji; Tahiti; American Samoa; San Cristobal, Galapagos; Natal, Brazil, Malindi, Kenya; Paramaribo, Surinam. From the first 3-4 years of data (presently greater than 1700 sondes), the following features emerge: (a) highly variable tropospheric ozone; (b) a zonal wave-one pattern in tropospheric column ozone; (c) tropospheric ozone variability over the Indian and Pacific Ocean displays strong convective signatures.

  20. Characteristics of Perturbed Tropical Upper Tropospheric Ozone from SHADOZ (Southern Hemisphere Additional Ozonesondes) and pre-SHADOZ Soundings

    NASA Astrophysics Data System (ADS)

    Stone, J. B.; Thompson, A. M.; Lee, S.; Oltmans, S. J.; Solomon, S.; Witte, J. C.; Miller, S. K.; Schmidlin, F. J.

    2005-12-01

    SHADOZ (Southern Hemisphere Additional Ozonesondes) is part of Aura's constellation of validation efforts. Aura's interest in multi-instrument estimates of tropospheric ozone requires high-quality ozone measurements in the UT/LS. Within this region, primarily below 100 hPa, increases in the frequency of very low (< 20 ppbv) and near-zero ozone mixing ratios have been reported recently (Solomon et al, GRL, in press, 2005). These findings are based on ozone soundings at selected SHADOZ (1998-2004) stations where 1980's and early 1990's profiles are available. The location (preference for the western Pacific "warm pool" region) and morphology of these changes (100-300 hPa location in most cases) suggest perturbations in deep convection. Key meteorological variables corresponding to the low-ozone episodes are examined to evaluate potential processes related to change.

  1. Toward a Quantitative Assessment of the Influence of Regional Emission Sources on Ozone Production in the Colorado Front Range

    NASA Astrophysics Data System (ADS)

    McDuffie, E. E.; Dube, W. P.; Wolfe, D. E.; Tevlin, A.; Gilman, J.; Lerner, B. M.; De Gouw, J. A.; Murphy, J. G.; Fischer, E. V.; Brown, S. S.; Angevine, W. M.; Edwards, P.; Williams, E. J.

    2015-12-01

    Photochemical ozone production results from the oxidation and reaction of volatile organic compounds (VOCs) with nitrogen oxides (NOx = NO2 + NO). As with many US urban regions, ozone levels observed in the Northern Front Range Metropolitan Region of Colorado are influenced by urban emissions of NOx and VOCs. Despite nationwide decreases in these urban emissions, the Front Range of Colorado is one of the few US locations where ozone is currently increasing. It has also recently gone out of compliance with national ambient air quality standards for ozone during summer months. High ozone in Colorado may result from a number of factors, including long-range transport from Asia, increased influence of biomass burning, population increases, or increased emissions from oil and gas activities. The Front Range is home to the Denver-Julesburg (D-J) Basin, which has recently been experiencing a rise in oil and natural gas (O&NG) activity associated with the increase in non-conventional drilling techniques. The VOC and NOx emissions from O&NG activity in close proximity to the urban area may uniquely influence ozone in this region. This presentation will focus on using reactive nitrogen (NOx, NOy) and ozone measurements from a tall (300 m) tower to study the influence of local emissions on Front Range ozone. The tower is located between the D-J Basin and agricultural areas to the north and the Denver metro area to the south. In-situ reactive nitrogen and ozone measurements were collected using a custom Cavity Ring-Down instrument. Additional CH4, CO, and NH3 measurements from the tower serve as tracers for O&NG, urban, and agricultural emissions. Concurrently measured aircraft data is used to confirm the relationships between the tracer species. This presentation will discuss methods for determining the contributions of different emission sources to Front Range ozone, with a focus on differentiating the influence of urban and O&NG sources.

  2. Comparing Chemical Mechanisms using Tagged Ozone Production Potentials

    NASA Astrophysics Data System (ADS)

    Coates, J.; Butler, T. M.

    2013-12-01

    Tropospheric ozone (O3) is a short-lived climate forcing pollutant that is detrimental to human health and crop growth. It is produced by reactions of volatile organic compounds (VOCs) and nitrogen oxides (NOx) in the presence of sunlight [Atkinson,2000]. The chemistry of intermediate species formed during VOC degradation show a time dependence and impacts the amount of O3 produced by the VOC [Butler et al., 2011]. Representing the intricacies of these reactions is not viable for chemical mechanisms used in global and regional models due to the computational resources available. Thus, chemical mechanisms reduce the amount of reactions either by lumping chemical species together as a model species, reducing the number of reaction pathways or both. As different chemical mechanisms use varying reduction techniques and assumptions especially with respect to the intermediate degradation species, it is important to compare the temporal evolution of ozone production obtained from differing chemical mechanisms. In this study, chemical mechanisms are compared using Tagged Ozone Production Potentials (TOPP) [Butler et al.,2011]. TOPPs measure the effect of a VOC on the odd oxygen family (Ox), which includes O3, nitrogen dioxide (NO2) and other species whose cycling effect O3 and NO2 production. TOPP values are obtained via a boxmodel run lasting seven diurnal cycles and tagging all species produced during VOC degradation; this enables the Ox production to be attributed to the VOC. This technique enables the temporal evolution of a VOCs' Ox production to be compared between the mechanisms. Comparing the TOPP profiles of the VOCs obtained using different mechanisms shows the effect of reduction techniques implemented by the mechanism and also allows a comparison of the tropospheric chemistry represented in the mechanisms. [Atkinson,2000] Atkinson, R. (2000). Atmospheric chemistry of VOCs and NOx. Atmospheric Environment, 34:2063-2101 [Butler et al., 2011] Butler, T. M

  3. Identifying the causes of differences in ozone production from the CB05 and CBMIV chemical mechanisms

    NASA Astrophysics Data System (ADS)

    Saylor, R. D.; Stein, A. F.

    2011-10-01

    An investigation was conducted to identify the mechanistic differences between two versions of the carbon bond gas-phase chemical mechanism (CB05 and CBMIV) which consistently lead to larger ground-level ozone concentrations being produced in the CB05 version of the National Air Quality Forecasting Capability (NAQFC) modeling system even though the two parallel forecast systems utilize the same meteorology and base emissions and similar initial and boundary conditions. Box models of each of the mechanisms as they are implemented in the NAQFC were created and a set of 12 sensitivity simulations was designed. The sensitivity simulations independently probed the conceptual mechanistic differences between CB05 and CBMIV and were exercised over a 45-scenario simulation suite designed to emulate the wide range of chemical regimes encountered in a continental-scale atmospheric chemistry model. Results of the sensitivity simulations indicate that two sets of reactions that were included in the CB05 mechanism, but which were absent from the CBMIV mechanism, are the primary causes of the greater ozone production in the CB05 version of the NAQFC. One set of reactions recycles the higher organic peroxide species of CB05 (ROOH), resulting in additional photochemically reactive products that act to produce additional ozone in some chemical regimes. The other set of reactions recycles reactive nitrogen from less reactive forms back to NO2, increasing the effective NOx concentration of the system. In particular, the organic nitrate species (NTR), which was a terminal product for reactive nitrogen in the CBMIV mechanism, acts as a reservoir species in CB05 to redistribute NOx from major source areas to potentially NOx-sensitive areas where additional ozone may be produced in areas remote from direct NOx sources.

  4. Identifying the causes of differences in ozone production from the CB05 and CBMIV chemical mechanisms

    NASA Astrophysics Data System (ADS)

    Saylor, R. D.; Stein, A. F.

    2012-02-01

    An investigation was conducted to identify the mechanistic differences between two versions of the carbon bond gas-phase chemical mechanism (CB05 and CBMIV) which consistently lead to larger ground-level ozone concentrations being produced in the CB05 version of the National Air Quality Forecasting Capability (NAQFC) modeling system even though the two parallel forecast systems utilize the same meteorology and base emissions and similar initial and boundary conditions. Box models of each of the mechanisms as they are implemented in the NAQFC were created and a set of 12 sensitivity simulations was designed. The sensitivity simulations independently probed the conceptual mechanistic differences between CB05 and CBMIV and were exercised over a 45-scenario simulation suite designed to emulate the wide range of chemical regimes encountered in a continental-scale atmospheric chemistry model. Results of the sensitivity simulations indicate that two sets of reactions that were included in the CB05 mechanism, but which were absent from the CBMIV mechanism, are the primary causes of the greater ozone production in the CB05 version of the NAQFC. One set of reactions recycles the higher organic peroxide species of CB05 (ROOH), resulting in additional photochemically reactive products that act to produce additional ozone in some chemical regimes. The other set of reactions recycles reactive nitrogen from less reactive forms back to NO2, increasing the effective NOx concentration of the system. In particular, the organic nitrate species (NTR), which was a terminal product for reactive nitrogen in the CBMIV mechanism, acts as a reservoir species in CB05 to redistribute NOx from major source areas to potentially NOx-sensitive areas where additional ozone may be produced in areas remote from direct NOx sources.

  5. The use of ozonation and catalytic ozonation combined with ultrafiltration for the control of natural organic matter (NOM) and disinfection by-products (DBPs) in drinking water

    NASA Astrophysics Data System (ADS)

    Karnik, Bhavana Sushilkumar

    Commercially available titania membranes, with a molecular weight cut-off of 15, 5, 1 kD were used in a ozonation/membrane system that was fed with water from Lake Lansing. The effects of ozonation on permeate flux recovery and membrane fouling was investigated. In addition the effects of ozonation/membrane filtration hybrid process on the removal of the natural organic matter (NOM) and the formation of disinfection by-products (DBPS) were monitored. The commercial membrane (CeRAM Inside, Tami North America, St. Laurent, Quebec, Canada) was coated with iron oxide nanoparticles (4--6 nm in diameter) using a layer-by-layer technique and sintered in air for 30 minutes. Surface characterization was carried out using electron microscopy techniques and atomic force microscopy, to study the changes in structure and surface morphology of the membranes. The removal and survival of bacteria in the process was also evaluated using fluorescence microscopy and microbial assays. Finally the surface catalytic reaction was investigated to propose the mechanism responsible for the improved performance of the hybrid process. The permeate flux through a titania coated ceramic membrane was significantly affected by ozonation. A minimum threshold ozone concentration (2.5 g/m 3) could achieve complete recovery of permeate flux after fouling. Ozonation/filtration decreased the concentration of chlorinated disinfection by-products up to 80%. With catalyst coated membranes, the concentration of dissolved organic carbon was reduced by >85% and the concentrations of disinfection by-products decreased by up to 90%. Furthermore with the coated membrane, the concentrations of ozonation by-products in the permeate were reduced by >50% as compared to that obtained with the uncoated membranes, thus reducing the risk of potential regrowth of bacteria in the distribution system. Application of the hybrid process lead to greater than 7 log removal of bacteria. Surface characterization showed that

  6. The changing oxidizing environment in London - trends in ozone precursors and their contribution to ozone production

    NASA Astrophysics Data System (ADS)

    von Schneidemesser, E.; Vieno, M.; Monks, P. S.

    2014-01-01

    Ground-level ozone is recognized to be a threat to human health (WHO, 2003), have a deleterious impact on vegetation (Fowler et al., 2009), is also an important greenhouse gas (IPCC, 2007) and key to the oxidative ability of the atmosphere (Monks et al., 2009). Owing to its harmful effect on health, much policy and mitigation effort has been put into reducing its precursors - the nitrogen oxides (NOx) and non-methane volatile organic compounds (NMVOCs). The non-linear chemistry of tropospheric ozone formation, dependent mainly on NOx and NMVOC concentrations in the atmosphere, makes controlling tropospheric ozone complex. Furthermore, the concentration of ozone at any given point is a complex superimposition of in-situ produced or destroyed ozone and transported ozone on the regional and hemispheric-scale. In order to effectively address ozone, a more detailed understanding of its origins is needed. Here we show that roughly half (5 μg m-3) of the observed increase in urban (London) ozone (10 μg m-3) in the UK from 1998 to 2008 is owing to factors of local origin, in particular, the change in NO : NO2 ratio, NMVOC : NOx balance, NMVOC speciation, and emission reductions (including NOx titration). In areas with previously higher large concentrations of nitrogen oxides, ozone that was previously suppressed by high concentrations of NO has now been "unmasked", as in London and other urban areas of the UK. The remaining half (approximately 5 μg m-3) of the observed ozone increase is attributed to non-local factors such as long-term transport of ozone, changes in background ozone, and meteorological variability. These results show that a two-pronged approach, local action and regional-to-hemispheric cooperation, is needed to reduce ozone and thereby population exposure, which is especially important for urban ozone.

  7. Regeneration of Aqueous Periodate Solutions by Ozone Treatment: A Sustainable Approach for Dialdehyde Cellulose Production.

    PubMed

    Koprivica, Slavica; Siller, Martin; Hosoya, Takashi; Roggenstein, Walter; Rosenau, Thomas; Potthast, Antje

    2016-04-21

    A method for easy and fast regeneration of aqueous periodate solutions from dialdehyde cellulose (DAC) production by ozone treatment is presented, along with a direct and reliable simultaneous quantification of iodate and periodate by reversed-phase HPLC. The influence of iodate and ozone concentration, solution pH, and reaction time on the regeneration efficiency was studied, as well as the reaction kinetics. Regeneration of spent periodate solutions by ozone was successfully performed in alkaline medium, which favors the formation of free (.) OH radicals, as supported by the addition of radical scavengers and quantum mechanical calculations. At pH 13 and an ozone concentration of approximately 150 mg L(-1) , periodate was completely regenerated from a 100 mm solution of iodate within 1 h at room temperature. A cyclic process of cellulose oxidation and subsequent regeneration of spent periodate with 90 % efficiency has been developed. So far, commercial applications of DAC have been hampered by difficulties in reusing the costly periodate. This work overcomes this hurdle and presents a highly efficient, clean, and low-cost protocol for the preparation of DAC with integrated periodate recycling, with the possibility of scaling the process up. PMID:26990816

  8. Enhancement of free tropospheric ozone production by deep convection

    NASA Technical Reports Server (NTRS)

    Pickering, Kenneth E.; Thompson, Anne M.; Scala, John R.; Tao, Wei-Kuo; Simpson, Joanne

    1994-01-01

    It is found from model simulations of trace gas and meteorological data from aircraft campaigns that deep convection may enhance the potential for photochemical ozone production in the middle and upper troposphere by up to a factor of 60. Examination of half a dozen individual convective episodes show that the degree of enhancement is highly variable. Factors affecting enhancement include boundary layer NO(x) mixing ratios, differences in the strength and structure of convective cells, as well as variation in the amount of background pollution already in the free troposphere.

  9. Ozonation of Canadian Athabasca asphaltene

    NASA Astrophysics Data System (ADS)

    Cha, Zhixiong

    . Two new solvent systems, a self-sustaining ozonation system and a cyclohexane/acetone/water or a cyclohexane/acetone/methanol system, were studied to overcome the drawback of using halogenated solvents. The self-sustaining ozonation process employed the final ozonation products as the reaction solvent. Compared to the self-sustaining ozonation, the cyclohexane solvent system showed higher ozone efficiency; however, it required dynamic adjustment of the solvent system during ozonation. An extensively ozonated asphaltene's weight would be doubled. Distillation of the products separated about 45% volatile products having biodiesel-style chemical structures. Compared to distillation, more than 90% of the ozonation products were extractable by acetone. The remaining acetone-insoluble part was further classified by dichloromethane and other solvents of different polarities. The separated ozonation products were good fuel additives or materials for other products.

  10. The Southern Hemisphere Additional Ozonesondes (SHADOZ) 1998-2002 Tropical Ozone Climatology. 3; Instrumentation and Station-to-Station Variability

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Witte, Jacqueline C.; Smit, Herman G. J.; Oltmans, Samuel J.; Johnson, Bryan J.; Kirchhoff, Volker W. J. H.; Schmidlin, Francis J.

    2004-01-01

    Abstract: Since 1998 the Southern Hemisphere ADditional OZonesondes (SHADOZ) project has collected more than 2000 ozone profiles from a dozen tropical and subtropical sites using balloon-borne electrochemical concentration cell (ECC) ozonesondes. The data (with accompanying pressure-temperature-humidity soundings) are archived. Analysis of ozonesonde imprecision within the SHADOZ dataset revealed that variations in ozonesonde technique could lead to station-to-station biases in the measurements. In this paper imprecisions and accuracy in the SHADOZ dataset are examined in light of new data. When SHADOZ total ozone column amounts are compared to version 8 TOMS (2004 release), discrepancies between sonde and satellite datasets decline 1-2 percentage points on average, compared to version 7 TOMS. Variability among stations is evaluated using total ozone normalized to TOMS and results of laboratory tests on ozonesondes (JOSE-2O00, Julich Ozonesonde Intercomparison Experiment). Ozone deviations from a standard instrument in the JOSE flight simulation chamber resemble those of SHADOZ station data relative to a SHADOZ-defined climatological reference. Certain systematic variations in SHADOZ ozone profiles are accounted for by differences in solution composition, data processing and instrument (manufacturer). Instrument bias leads to a greater ozone measurement above 25 km over Nairobi and to lower total column ozone at three Pacific sites compared to other SHADOZ stations at 0-20 deg.S.

  11. Ozone decreases soybean productivity and water use efficiency

    NASA Astrophysics Data System (ADS)

    Betzelberger, A. M.; VanLoocke, A. D.; Ainsworth, E. A.; Bernacchi, C. J.

    2011-12-01

    The combination of population growth and climate change will increase pressure on agricultural and water resources throughout this century. An additional consequence of this growth is an increase in anthropogenic emissions that lead to the formation of tropospheric ozone (O3), which in concert with climate change, poses a significant threat to human health and nutrition. In addition to being an important greenhouse gas, O3 reduces plant productivity, an effect that has been particularly pronounced in soybean, which provides over half of the world's oilseed production. Plant productivity is linked to feedbacks in the climate system, indirectly through the carbon cycle, as well as directly through the partitioning of radiation into heat and moisture fluxes. Soybean, along with maize, comprises the largest ecosystem in the contiguous U.S. Therefore, changes in productivity and water use under increasing O3 could impact human nutrition as well as the regional climate. Soybean response to increasing O3 concentrations was tested under open-air agricultural conditions at the SoyFACE research site. During the 2009 growing season, eight 20 m diameter FACE plots were exposed to different O3 concentrations, ranging from 40 to 200 ppb. Canopy growth (leaf area index) and physiological measurements of leaf photosynthesis and stomatal conductance were taken regularly throughout the growing season. Canopy fluxes of heat and moisture were measured using the residual energy balance micrometeorological technique. Our results indicate that as O3 increased from 40 to 200 ppb, rates of photosynthesis and stomatal conductance decreased significantly. Further, the seed yield decreased by over 60%, while water use decreased by 30% and the water-use-efficiency (yield/water-use) declined by 50%. The growing season average canopy temperatures increased by 1°C and midday temperatures increased by 2°C compared to the control. Warmer and drier canopies may result in a positive feedback on O3

  12. Quantifying Ozone Production throughout the Boundary Layer from High Frequency Tethered Profile Measurements during a High Ozone Episode in the Uinta Basin, Utah

    NASA Astrophysics Data System (ADS)

    Sterling, C. W.; Johnson, B.; Schnell, R. C.; Oltmans, S. J.; Cullis, P.; Hall, E. G.; Jordan, A. F.; Windell, J.; McClure-Begley, A.; Helmig, D.; Petron, G.

    2015-12-01

    During the Uinta Basin Winter Ozone Study (UBWOS) in Jan - Feb 2013, 735 tethered ozonesonde profiles were obtained at 3 sites including during high wintertime photochemical ozone production events that regularly exceeded 125 ppb. High resolution profiles of ozone and temperature with altitude, measured during daylight hours, showed the development of approximately week long high ozone episodes building from background levels of ~40 ppb to >150 ppb. The topography of the basin combined with a strong temperature inversion trapped oil and gas production effluents in the basin and the snow covered surface amplified the sun's radiation driving the photochemical ozone production at rates up to 13 ppb/hour in a cold layer capped at 1600-1700 meters above sea level. Beginning in mid-morning, ozone mixing ratios throughout the cold layer increased until late afternoon. Ozone mixing ratios were generally constant with height indicating that ozone production was nearly uniform throughout the depth of the cold pool. Although there was strong diurnal variation, ozone mixing ratios increased during the day more than decreased during the night, resulting in elevated levels the next morning; an indication that nighttime loss processes did not compensate for daytime production. Even though the 3 tethersonde sites were at elevations differing by as much as 140 m, the top of the high ozone layer was nearly uniform in altitude at the 3 locations. Mobile van surface ozone measurements across the basin confirmed this capped structure of the ozone layer; the vehicle drove out of high ozone mixing ratios at an elevation of ~1900 meters above sea level, above which free tropospheric ozone mixing ratios of ~50 ppb were measured. Exhaust plumes from a coal-fired power plant in the eastern portion of the basin were intercepted by the tethersondes. The structure of the profiles clearly showed that effluents in the plumes were not mixed downward and thus did not contribute precursor nitrogen

  13. Ozone Production from the 2004 North American Boreal Fires

    NASA Technical Reports Server (NTRS)

    Pfister, G. G.; Emmons, L. K.; Hess, P. G.; Honrath, R.; Lamarque, J.-F.; Val Martin, M.; Owen, R. C.; Avery, M. A.; Browell, E. V.; Holloway, J. S.; Nedelec, P.; Purvis, R.; Ryerson, T. B.; Sachse, G. W.; Schlager, H.

    2006-01-01

    We examine the ozone production from boreal forest fires based on a case study of wildfires in Alaska and Canada in summer 2004. The model simulations were performed with the chemistry transport model, MOZART-4, and were evaluated by comparison with a comprehensive set of aircraft measurements. In the analysis we use measurements and model simulations of carbon monoxide (CO) and ozone (O3) at the PICO-NARE station located in the Azores within the pathway of North American outflow. The modeled mixing ratios were used to test the robustness of the enhancement ratio deltaO3/deltaCO (defined as the excess O3 mixing ratio normalized by the increase in CO) and the feasibility for using this ratio in estimating the O3 production from the wildfires. Modeled and observed enhancement ratios are about 0.25 ppbv/ppbv which is in the range of values found in the literature, and results in a global net O3 production of 12.9 2 Tg O3 during summer 2004. This matches the net O3 production calculated in the model for a region extending from Alaska to the East Atlantic (9-11 Tg O3) indicating that observations at PICO-NARE representing photochemically well-aged plumes provide a good measure of the O3 production of North American boreal fires. However, net chemical loss of fire related O3 dominates in regions far downwind from the fires (e.g. Europe and Asia) resulting in a global net O3 production of 6 Tg O3 during the same time period. On average, the fires increased the O3 burden (surface-300 mbar) over Alaska and Canada during summer 2004 by about 7-9%, and over Europe by about 2-3%.

  14. Ozone production from the 2004 North American boreal fires

    NASA Astrophysics Data System (ADS)

    Pfister, G. G.; Emmons, L. K.; Hess, P. G.; Honrath, R.; Lamarque, J.-F.; Val Martin, M.; Owen, R. C.; Avery, M. A.; Browell, E. V.; Holloway, J. S.; Nedelec, P.; Purvis, R.; Ryerson, T. B.; Sachse, G. W.; Schlager, H.

    2006-12-01

    We examine the ozone production from boreal forest fires based on a case study of wildfires in Alaska and Canada in summer 2004. The model simulations were performed with the chemistry transport model, MOZART-4, and were evaluated by comparison with a comprehensive set of aircraft measurements. In the analysis we use measurements and model simulations of carbon monoxide (CO) and ozone (O3) at the PICO-NARE station located in the Azores within the pathway of North American outflow. The modeled mixing ratios were used to test the robustness of the enhancement ratio ΔO3/ΔCO (defined as the excess O3 mixing ratio normalized by the increase in CO) and the feasibility for using this ratio in estimating the O3 production from the wildfires. Modeled and observed enhancement ratios are about 0.25 ppbv/ppbv which is in the range of values found in the literature and results in a global net O3 production of 12.9 ± 2 Tg O3 during summer 2004. This matches the net O3 production calculated in the model for a region extending from Alaska to the east Atlantic (9-11 Tg O3) indicating that observations at PICO-NARE representing photochemically well aged plumes provide a good measure of the O3 production of North American boreal fires. However, net chemical loss of fire-related O3 dominates in regions far downwind from the fires (e.g., Europe and Asia) resulting in a global net O3 production of 6 Tg O3 during the same time period. On average, the fires increased the O3 burden (surface -300 mbar) over Alaska and Canada during summer 2004 by about 7-9% and over Europe by about 2-3%.

  15. Inferring Ozone Production in an Urban Atmosphere using Measurements of Peroxynitric Acid

    NASA Technical Reports Server (NTRS)

    Spencer, K. M.; McCabe, D. C.; Crounse, J. D.; Olson, J. R.; Crawford, J. H.; Weinheimer, A. J.; Knapp, D. J.; Montzka, D. D.; Cantrell, C. A.; Anderson, R. S.; Mauldin, R. L.; Wennberg, P. O.

    2009-01-01

    Observations of peroxynitric acid (HO2NO2) obtained simultaneously with those of NO and NO2 provide a sensitive measure of the ozone photochemical production rate. We illustrate this technique for constraining the ozone production rate with observations obtained from the NCAR C-130 aircraft platform during the Megacity Initiative: Local and Global Research Observations (MILAGRO) intensive in Mexico during the spring of 2006. Sensitive and selective measurements of HO2NO2 were made in situ using chemical ionization mass spectrometry (CIMS). Observations were compared to modeled HO2NO2 concentrations obtained from the NASA Langley highly-constrained photochemical time-dependent box model. The median observed-to-calculated ratio of HO2NO2 is 1.18. At NOx levels greater than 15 ppbv, the photochemical box model underpredicts observations with an observed-to-calculated ratio of HO2NO2 of 1.57. As a result, we find that at high NOx, the ozone production rate calculated using measured HO2NO2 is faster than predicted using accepted photochemistry. Inclusion of an additional HOx source from the reaction of excited state NO2 with H2O or reduction in the rate constant of the reaction of OH with NO2 improves the agreement.

  16. OMI Total Ozone Column Product Validated Against UVMFR Retrievals

    NASA Astrophysics Data System (ADS)

    Ioannis, Raptis Panagiotis; Kazadziz, Stelios; Eleftherantos, Kostas; Kosmopoulos, Panagiotis; Amiridis, Vassilis

    2015-06-01

    The Ozone Monitoring Instrument (OMI) is a spectroradiometer on board NASA Aura, providing Total Ozone Column (TOC), almost globally, every day, with a spatial resolution of 13kmX24 km, since July 2004. In the next few months Sentinel-5P will be launched, and carry TROPOMI, a spaceborne nadir viewing spectrometer which will cover tha same spectral range, narrowing the spatial resolution to 7 km X 7 km and extending current data record. Studies have evaluated OMI’s product using Brewer spectroradiometer measurements and found average biases to be less than 3%. UVMFR (Ultraviolet Multifilter Radiometer) is an instrument designed to measure total and diffuse and calculate Direct solar Irradiance at 7 wavelengths in the UV spectrum, with high accuracy and very high frequency. Main advantages of this instrument is the portability, the automatic calibration procedure, simple operational use, unattended functionality and the relatively low cost. In that frame it could become a very effective solution to validate satellite products. A method was developed to retrieve TOC, from UVMFR measurements combined with radiative transfer model calculations. Lookup tables of ratios of direct solar irradiance at 305nm and 325nm in respect to TOC, Solar Zenith Angle and Aerosol Optical Depth have been constructed and compared with UVMFR irradiance measurements in order to retrieve TOC. We used UVMFR measurements in Athens, Greece during the period July 2009 to May 2014 to create a TOC time series with high temporal frequency (1 minute for cloudless conditions). The validation of the method have been assessed using a Brewer spectroradiometer operating in parallel for the whole period. In order to compare OMI-based and ground-based TOC measurements we have calculated UVMFR daily values of TOC averaging measurements in a 2 hour window around OMI overpass. This comparison revealed differences up to 7%, with mean differences at 4.2 DU and standard deviation of 8.7%. Same seasonal cycle

  17. Ozone and Ozone By-Products in the Cabins of Commercial Aircraft

    PubMed Central

    Weisel, Clifford; Weschler, Charles J.; Mohan, Kris; Vallarino, Jose; Spengler, John D.

    2013-01-01

    The aircraft cabin represents a unique indoor environment due to its high surface-to-volume ratio, high occupant density and the potential for high ozone concentrations at cruising altitudes. Ozone was continuously measured and air was sampled on sorbent traps, targeting carbonyl compounds, on 52 transcontinental U.S. or international flights between 2008 and 2010. The sampling was predominantly on planes that did not have ozone scrubbers (catalytic converters). Peak ozone levels on aircraft without catalytic convertors exceeded 100 ppb, with some flights having periods of more than an hour when the ozone levels were > 75ppb. Ozone was greatly reduced on relatively new aircraft with catalytic convertors, but ozone levels on two flights whose aircraft had older convertors were similar to those on planes without catalytic convertors. Hexanal, heptanal, octanal, nonanal, decanal and 6-methyl-5-hepten-2-one (6-MHO) were detected in the aircraft cabin at sub- to low ppb levels. Linear regression models that included the log transformed mean ozone concentration, percent occupancy and plane type were statistically significant and explained between 18 and 25% of the variance in the mixing ratio of these carbonyls. Occupancy was also a significant factor for 6-MHO, but not the linear aldehydes, consistent with 6-MHO’s formation from the reaction between ozone and squalene, which is present in human skin oils. PMID:23517299

  18. Additive manufacturing in production: challenges and opportunities

    NASA Astrophysics Data System (ADS)

    Ahuja, Bhrigu; Karg, Michael; Schmidt, Michael

    2015-03-01

    Additive manufacturing, characterized by its inherent layer by layer fabrication methodology has been coined by many as the latest revolution in the manufacturing industry. Due to its diversification of Materials, processes, system technology and applications, Additive Manufacturing has been synonymized with terminology such as Rapid prototyping, 3D printing, free-form fabrication, Additive Layer Manufacturing, etc. A huge media and public interest in the technology has led to an innovative attempt of exploring the technology for applications beyond the scope of the traditional engineering industry. Nevertheless, it is believed that a critical factor for the long-term success of Additive Manufacturing would be its ability to fulfill the requirements defined by the traditional manufacturing industry. A parallel development in market trends and product requirements has also lead to a wider scope of opportunities for Additive Manufacturing. The presented paper discusses some of the key challenges which are critical to ensure that Additive Manufacturing is truly accepted as a mainstream production technology in the industry. These challenges would highlight on various aspects of production such as product requirements, process management, data management, intellectual property, work flow management, quality assurance, resource planning, etc. In Addition, changing market trends such as product life cycle, mass customization, sustainability, environmental impact and localized production will form the foundation for the follow up discussion on the current limitations and the corresponding research opportunities. A discussion on ongoing research to address these challenges would include topics like process monitoring, design complexity, process standardization, multi-material and hybrid fabrication, new material development, etc.

  19. Ozone phytotoxicity evaluation and prediction of crops production in tropical regions

    NASA Astrophysics Data System (ADS)

    Mohammed, Nurul Izma; Ramli, Nor Azam; Yahya, Ahmad Shukri

    2013-04-01

    Increasing ozone concentration in the atmosphere can threaten food security due to its effects on crop production. Since the 1980s, ozone has been believed to be the most damaging air pollutant to crops. In Malaysia, there is no index to indicate the reduction of crops due to the exposure of ozone. Therefore, this study aimed to identify the accumulated exposure over a threshold of X ppb (AOTX) indexes in assessing crop reduction in Malaysia. In European countries, crop response to ozone exposure is mostly expressed as AOT40. This study was designed to evaluate and predict crop reduction in tropical regions and in particular, the Malaysian climate, by adopting the AOT40 index method and modifying it based on Malaysian air quality and crop data. Nine AOTX indexes (AOT0, AOT5, AOT10, AOT15, AOT20, AOT25, AOT30, AOT40, and AOT50) were analyzed, crop responses tested and reduction in crops predicted. The results showed that the AOT50 resulted in the highest reduction in crops and the highest R2 value between the AOT50 and the crops reduction from the linear regression analysis. Hence, this study suggests that the AOT50 index is the most suitable index to estimate the potential ozone impact on crops in tropical regions. The result showed that the critical level for AOT50 index if the estimated crop reduction is 5% was 1336 ppb h. Additionally, the results indicated that the AOT40 index in Malaysia gave a minimum percentage of 6% crop reduction; as contrasted with the European guideline of 5% (due to differences in the climate e.g., average amount of sunshine).

  20. Consistent ozone-induced decreases in pasture forage quality across several grassland types and consequences for UK lamb production.

    PubMed

    Hayes, Felicity; Mills, Gina; Jones, Laurence; Abbott, John; Ashmore, Mike; Barnes, Jeremy; Neil Cape, J; Coyle, Mhairi; Peacock, Simon; Rintoul, Naomi; Toet, Sylvia; Wedlich, Kerstin; Wyness, Kirsten

    2016-02-01

    In this study we have demonstrated that rising background ozone has the potential to reduce grassland forage quality and explored the implications for livestock production. We analysed pasture samples from seven ozone exposure experiments comprising mesotrophic, calcareous, haymeadow and sanddune unimproved grasslands conducted in open-top chambers, solardomes and a field release system. Across all grassland types, there were significant increases in acid detergent fibre, crude fibre and lignin content with increasing ozone concentration, resulting in decreased pasture quality in terms of the metabolisable energy content of the vegetation. We derived a dose-response function for metabolisable energy of the grassland with ozone concentration, applicable to a range of grassland types, and used this to predict effects on pasture quality of UK vegetation at 1 km resolution using modelled ozone data for 2007 and for predicted higher average ozone concentrations in 2020. This showed a potential total reduction in lamb production in the UK of approximately 4% in 2020 compared to 2007. The largest impacts were in geographical areas of modest ozone increases between the two years, but where large numbers of lambs were present. For an individual farmer working to a very small cost margin this could represent a large reduction in profit, both in regions where the impacts per lamb and those where the impacts per km(2) of grazing land are largest. In the short term farmers could adapt their lamb management in response to changed forage quality by additional supplementary feed of high metabolisable energy content. Nationally this increase in annual additional feed in 2020 compared to 2007 would be 2,166 tonnes (an increase of 0.7%). Of added concern are the longer-term consequences of continual deterioration of pasture quality and the implications for changes in farming practices to compensate for potential reductions in livestock production capacity. PMID:26595401

  1. Identification and structural elucidation of ozonation transformation products of estrone

    PubMed Central

    2013-01-01

    Background Quantitative methods for the analysis of contaminants of emerging concern (CECs) are abundant in the scientific literature. However, there are few reports on systematic methods of identification and structural identification of transformation products. For this reason, a new method based on high-resolution mass spectrometry and differential analysis was developed in order to facilitate and accelerate the process of identification and structural elucidation of transformation products CECs. This method was applied to the study of ozonation transformation products (OTPs) of the natural hormone estrone (E1). Results A control compare trend experiment consisting in the comparison of a control sample to several samples having been exposed to decreasing concentrations of O3(aq) indicated that 593 peaks could be associated with OTPs. After applying various filters to remove background noise, sample contaminants and signal spikes, this data set was reduced to 16 candidate peaks. By inspection of the shape of these peaks, only two compounds OTP-276 (m/z 275.12930) and OTP-318 (m/z 317.14008) were considered as good candidates for further study. Multi-stage tandem mass spectrometry (MSn) experiments of SPE extracts of the ozonated samples of E1 and of a deuterium-labeled analogue (E1-d4) showed that OTP-276 and OTP-318 had carboxylic acid and hydroxyl functional groups, as previously reported for OTPs of other hormones. Structures for these two compounds were proposed based on their MSn spectra. Conclusion These results indicate that the method proposed is a systematic and rapid approach to study transformation products of CECs. PMID:23618537

  2. Chlorofluorocarbon production scenarios: possible changes to stratospheric ozone

    SciTech Connect

    Wuebbles, D.J.; Tarp, R.L.; Nold, A.; Wood, W.P.

    1981-01-01

    As one aspect of the regulatory process, the Environmental Protection Agency has derived a series of scenarios for future atmospheric emission rates of the chlorofluorocarbons CFCl/sub 3/ (also referred to as F-11), CF/sub 2/Cl/sub 2/ (F-12), CCl/sub 2/FCClF/sub 2/(F-113), CClF/sub 2/CClF/sub 2/(F-114), and CClF/sub 2/CF/sub 3/ (F-115). These scenarios are based on potential industrial production and commercial applications, and the eventual release of these chemicals into the atmosphere. In this study, the potential effect on stratospheric ozone resulting from future chlorofluorocarbon emissions as suggested by these scenarios is examined. Assessments are based upon model calculations using the one-dimensional coupled transport and chemical kinetics model of the troposphere and stratosphere developed at Lawrence Livermore National Laboratory. The change in total ozone column calculated for the seven scenarios as a function of time is given. (JGB)

  3. Rapid increases in tropospheric ozone production and export from China

    NASA Astrophysics Data System (ADS)

    Verstraeten, Willem W.; Neu, Jessica L.; Williams, Jason E.; Bowman, Kevin W.; Worden, John R.; Boersma, K. Folkert

    2015-09-01

    Rapid population growth and industrialization have driven substantial increases in Asian ozone precursor emissions over the past decade, with highly uncertain impacts on regional and global tropospheric ozone levels. According to ozonesonde measurements, tropospheric ozone concentrations at two Asian sites have increased by 1 to 3% per year since 2000, an increase thought to contribute to positive trends in the ozone levels observed at North America’s West Coast. However, model estimates of the Asian contribution to North American ozone levels are not well-constrained by observations. Here we interpret Aura satellite measurements of tropospheric concentrations of ozone and its precursor NO2, along with its largest natural source, stratospheric ozone, using the TM5 global chemistry-transport model. We show that tropospheric ozone concentrations over China have increased by about 7% between 2005 and 2010 in response to two factors: a rise in Chinese emissions by about 21% and increased downward transport of stratospheric ozone. Furthermore, we find that transport from China of ozone and its precursors has offset about 43% of the 0.42 DU reduction in free-tropospheric ozone over the western United States that was expected between 2005 and 2010 as a result of emissions reductions associated with federal, state and local air quality policies. We conclude that global efforts may be required to address regional air quality and climate change.

  4. Effect of Ozone Addition on Combustion Efficiency of Hydrogen: Liquid-Oxygen Propellant in Small Rockets

    NASA Technical Reports Server (NTRS)

    Miller, Riley O.; Brown, Dwight D.

    1959-01-01

    An experimental study shows that 2 percent by weight ozone in oxygen has little effect on overall reactivity for a range of oxidant-fuel weight ratios from 1 to 6. This conclusion is based on characteristic-velocity measurements in 200-pound-thrust chambers at a pressure of 300 pounds per square inch absolute with low-efficiency injectors. The presence of 9 percent ozone in oxygen also did not affect performance in an efficient chamber. Explosions were encountered when equipment or procedure permitted ozone to concentrate locally. These experiments indicate that even small amounts of ozone in oxygen can cause operational problems.

  5. Increasing global agricultural production by reducing ozone damages via methane emission controls and ozone-resistant cultivar selection

    PubMed Central

    Avnery, Shiri; Mauzerall, Denise L; Fiore, Arlene M

    2013-01-01

    Meeting the projected 50% increase in global grain demand by 2030 without further environmental degradation poses a major challenge for agricultural production. Because surface ozone (O3) has a significant negative impact on crop yields, one way to increase future production is to reduce O3-induced agricultural losses. We present two strategies whereby O3 damage to crops may be reduced. We first examine the potential benefits of an O3 mitigation strategy motivated by climate change goals: gradual emission reductions of methane (CH4), an important greenhouse gas and tropospheric O3 precursor that has not yet been targeted for O3 pollution abatement. Our second strategy focuses on adapting crops to O3 exposure by selecting cultivars with demonstrated O3 resistance. We find that the CH4 reductions considered would increase global production of soybean, maize, and wheat by 23–102 Mt in 2030 – the equivalent of a ∼2–8% increase in year 2000 production worth $3.5–15 billion worldwide (USD2000), increasing the cost effectiveness of this CH4 mitigation policy. Choosing crop varieties with O3 resistance (relative to median-sensitivity cultivars) could improve global agricultural production in 2030 by over 140 Mt, the equivalent of a 12% increase in 2000 production worth ∼$22 billion. Benefits are dominated by improvements for wheat in South Asia, where O3-induced crop losses would otherwise be severe. Combining the two strategies generates benefits that are less than fully additive, given the nature of O3 effects on crops. Our results demonstrate the significant potential to sustainably improve global agricultural production by decreasing O3-induced reductions in crop yields. PMID:23504903

  6. Ozonation of indigo enhanced by carboxylated carbon nanotubes: performance optimization, degradation products, reaction mechanism and toxicity evaluation.

    PubMed

    Qu, Ruijuan; Xu, Bingzhe; Meng, Lingjun; Wang, Liansheng; Wang, Zunyao

    2015-01-01

    As a promising disinfection technique to replace chlorination, ozonation has been demonstrated to be efficient in water treatment. This paper describes an effective way to enhance the ozonation of indigo by using carbon nanotubes functionalized with carboxyl groups (CNTs-COOH) as catalysts. The result of kinetic studies showed that the presence of CNTs-COOH dramatically increased the decolorization rate of indigo. Different types of catalysts were compared to further elucidate the internal mechanism of the catalytic reaction and the special nanostructure and the functional –COOH groups are considered to play an important role in the catalytic ozonation process. Four aromatic intermediate products were identified using an electrospray time-of-flight mass spectrometer and further rationalized by the frontier electron density calculations. Ion chromatography analysis revealed that the nitrogen atom of indigo was released predominantly as ammonium and to a lesser extent as nitrate. The presence of the catalyst CNTs-COOH leads to a higher mineralization degree than single ozonation, as suggested by the total organic carbon (TOC) measurement. Three major carboxylic acids (i.e., oxalic, formic and acetic acids) were also identified as oxidation by-products, and they contributed significantly to the residual TOC after 2 h of ozonation. In addition, the toxicity evolution during the degradation was investigated through two aquatic model species to evaluate the potential ecological risks of the intermediate products. PMID:25462739

  7. Influence of Ar addition on ozone generation in a non-thermal plasma—a numerical investigation

    NASA Astrophysics Data System (ADS)

    Chen, Hsin Liang; Lee, How Ming; Chen, Shiaw Huei; Wei, Ta Chin; Been Chang, Moo

    2010-10-01

    A numerical model based on a dielectric barrier discharge is developed in this study to investigate the influence of Ar addition on ozone generation. The simulation results show good agreement with the experimental data, confirming the validity of the numerical model. The mechanisms regarding how the Ar addition affects ozone generation are investigated with the assistance of a numerical simulation by probing into the following two questions, (1) why the ozone concentration just slightly decreases in the low specific input energy (SIE, the ratio of discharge power to gas flow rate) region even if the inlet O2 concentration is substantially decreased and (2) why the variation of the increased rate of ozone concentration with SIE (i.e. the variation in the slope of ozone concentration versus SIE) is more significant for an O2/Ar mixture plasma. As SIE is relatively low, ozone decomposition through electron-impact and radical attack reactions is less significant because of low ozone concentration and gas temperature. Therefore, the ozone concentration depends mainly on the amount of oxygen atoms generated. The simulation results indicate that the amount of oxygen atoms generated per electronvolt for Ar concentrations of 0%, 10%, 30%, 50% and 80% are 0.178, 0.174, 0.169, 0.165 and 0.166, respectively, explaining why the ozone concentration does not decrease linearly with the inlet O2 concentration in the low SIE region. On the other hand, the simulation results show that increasing Ar concentration would lead to a lower reduced field and a higher gas temperature. The former would lead to an increase in the rate constant of e + O3 → e + O + O2 while the latter would result in a decrease in the rate constant of O + O2 + M → O3 + M and an increase in that of O3 + O → 2O2. The changes in the rate constants of these reactions would have a negative effect on ozone generation, which is the rationale for the second question.

  8. Oxidation of Reactive Nitrogen and Ozone Production in Tokyo

    NASA Astrophysics Data System (ADS)

    Fukuda, M.; Kondo, Y.; Miyazaki, Y.; Morino, Y.; Takegawa, N.; Miyakawa, T.; Komazaki, Y.; Tanimoto, H.; Yokouchi, Y.; Kanaya, Y.; McKenzie, R.; Johnston, P.

    2005-12-01

    Ground based measurements of NOx (NO + NO2), nitric acid (HNO3), particulate nitrate (NO3-), peroxyacyl nitrates (PANs), and total reactive nitrogen (NOy) were conducted in Tokyo in winter (January-February 2004), summer (July-August 2003 and 2004), and fall (October 2003). Carbon monoxide (CO), ozone (O3), non-methane hydrocarbons (NMHCs) and actinic flux were also measured during these periods. Average mixing ratios of these species and the NOx/NOy, HNO3/NOy, NO3-/NOy, and PANs/NOy ratios showed distinct diurnal-seasonal variations. The NOx/NOy ratios were 0.63-0.95 on high J(O1D) days, and 0.77-0.94 on low J(O1D) days. In summer and winter, total nitrate (TN = HNO3 + NO3-) was the dominant form of the NOx oxidation products (NOz = NOy - NOx) during the daytime on high J(O1D) days, and PANs were minor component species. The partitioning of TN was controlled mainly by temperature and the shit of the partitioning to NO3- at low temperature suppressed removal of NOy by dry deposition of HNO3. Removal rate of NOy is estimated using CO as a tracer. The estimated loss of NOy (LNOy) was largest during the daytime in summer (35%), while smallest (0%) in winter. The corrected ozone production efficiency (OPEx), which is defined as the linear regression slope of the observed Ox (= O3 + NO2) versus NOz* (= NOz + LNOy), is estimated to be 2.5. The estimated OPEx is slightly lower than those obtained in the U.S. urban air, which is probably due to lower ratios of NMHCs to NOx in this study. Possible factors controlling the OPEx will be discussed in detail.

  9. Ifluence of outer electrode material on ozone production in coaxial negative corona discharge fed by oxygen

    NASA Astrophysics Data System (ADS)

    Orszagh, J.; Skalny, J. D.; Mason, N. J.

    2008-07-01

    The "electric odour", observed by Van Marum when oxygen was passing trough electric spark in 1785, has been later (1839), identified by Ch. F. Schonbeim as a new chemical compound named ozone (Stolarski 1999). Almost from those times ozone is widely used chemical compound. The effect of outer electrode material on the ozone production in negative corona discharge have been studied. Two electrodes with the same dimensions were used in the experiment. One was made of stainless steel other one of brass. First the outer electrode was mechanically cleaned to remove the layer of oxides. The reactor have been filled by pure oxygen and closed. Then the measurement (1 hour measurement of discharge current at the constant voltage and time dependence of ozone concentration in the reactor) was repeated 5 times without cleaning the surface to see the ageing effects. Especially the influence of electrode oxidation on ozone concentration was studied. The experiments have been carried out at atmospheric pressure and ambient temperature. The ozone concentration was measured by UV spectroscopy method directly in the discharge reactor. As one can expect the brass surface was oxidizing faster. After five measurements the electrode surface was covered by layer of greenish oxides. On the other hand the steel electrode surface had no visible oxides layer. The oxidation of the outer electrode had little systematic effect on the ozone concentration but in case of brass electrode the results were scattered in the range from 8000 ppm to 15000 ppm of ozone. It seems that the more oxides are created on the surface the less ozone is produced or the faster the ozone decomposition processes are (see Fig. 1). On the other hand in case of stainless steel electrode the ozone concentrations were comparable in all 5 measurements. Overall ozone concentration was higher in steel electrode. Figure 1: Time dependence of ozone concentration.

  10. Effect of magnetic ion exchange and ozonation on disinfection by-product formation.

    PubMed

    Kingsbury, Ryan S; Singer, Philip C

    2013-03-01

    The purpose of this research was to investigate the performance of treatment with magnetic ion exchange (MIEX) resin followed by ozonation in achieving disinfection goals while controlling bromate and chlorinated disinfection by-product (DBP) formation. Three water samples were collected from raw water supplies impacted by the San Francisco Bay Delta to represent the varying levels of bromide and total organic carbon (TOC) that occur throughout the year. A fourth water was prepared by spiking bromide into a portion of one of the samples. Samples of each water were pre-treated with alum or virgin MIEX resin, and the raw and treated waters were subsequently ozonated under semi-batch conditions to assess the impact of treatment on ozone demand, ozone exposure for disinfection ("CT"), and bromate formation. Finally, aliquots of raw, coagulated, resin-treated, and ozonated waters were chlorinated in order to measure trihalomethane formation potential (THMFP). In the waters studied, MIEX resin removed 41-68% of raw water TOC, compared to 12-44% for alum. MIEX resin also reduced the bromide concentration by 20-50%. The removal of TOC by alum and MIEX resin significantly reduced the ozone demand of all waters studied, resulting in higher dissolved ozone concentrations and CT values for a given amount of ozone transferred into solution. For a given level of disinfection (CT), the amount of bromate produced by ozonation of MIEX-treated waters was similar to or slightly less than that of raw water and significantly less than that of alum-treated water. MIEX resin removed 39-85% of THMFP compared to 16-56% removal by alum. Ozonation reduced THMFP by 35-45% in all cases. This work indicates that in bromide-rich waters in which ozone disinfection is used, MIEX resin is a more appropriate treatment than alum for the removal of organic carbon, as it achieves superior TOC and THM precursor removal and decreases the production of bromate from ozone. PMID:23286989

  11. Comparison of Wintertime Ozone Production Associated With Oil and Gas Extraction Activity in Wyoming and Utah

    NASA Astrophysics Data System (ADS)

    Oltmans, S. J.; Schnell, R. C.; Mefford, T. K.; Neely, R. R., III

    2012-12-01

    The wintertime cold, reduced sunlight conditions of the mid-latitudes of continental interior locations are normally not considered to be conducive to significant ozone production. Recent observations have shattered this expectation with hourly ozone mixing ratios regularly exceeding 100 ppb measured in January, February and March in the states of Wyoming and Utah in the United States. Maximum daily eight hour average ozone mixing ratios have exceeded 100 ppb, far exceeding the U.S. threshold of 75 ppb. Conditions under which this dramatic ozone production takes place include a mix of high levels of ozone precursors (NOx and VOCs), a very stable and shallow boundary layer, snow cover providing enhanced UV radiation, and air confining terrain features. The high levels of precursors have been tied to oil and gas extraction activities in the affected regions. Under the requisite meteorological conditions where high pressure, low winds, and snow-covered ground are present extremely stable and shallow (~50-200 m) boundary layers persist. The highly reflective snow cover provides enhanced photolysis rates that in February can exceed those in June. For several winters in Utah and Wyoming with large ozone enhancements, the time series of various meteorological (wind, temperature, solar radiation, snow cover) and chemical parameters (ozone and NOx) show a somewhat different progression of high ozone events between the two locations. In the Unitah Basin of Utah high ozone formation conditions are more persistent throughout the winter than in the Pinedale Anticline region of Wyoming. This is likely a function of the differing topography of the two areas. However, for individual events the two sites show a similar progression of rapid ozone formation each day. Sites in both Utah and Wyoming just outside the oil and gas extraction activity areas show little or no enhanced ozone. Winters without the requisite meteorological conditions also do not experience high ozone events.

  12. DISINFECTION BY-PRODUCT FORMATION AND CONTROL BY OZONATION AND BIOTREATMENT

    EPA Science Inventory

    There is increasing interest in using ozone in water treatment because it is a strong disinfectant and is able to oxidize the precursors of some disinfection by-products (DBPs). However, ozonation itself produces DBPs, like aldehydes and ketones, and increases the concentration ...

  13. Preparation of oxygen-containing organic products from bed-oxidized brown coal by ozonation

    SciTech Connect

    Semenova, S.A.; Patrakov, Y.F.; Batina, M.V.

    2009-01-15

    The possibility of modifying the functional composition of humic acids by gas-phase ozonation of bed-oxidized brown coal was examined. About 90% of the organic matter of brown coal was converted to low-molecular weight soluble oxygen-containing products by stepwise liquid-phase ozonation (in chloroform and acetic acid).

  14. The effects of tropospheric ozone on net primary production and implications for climate change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropospheric ozone (O3) is a global air pollutant that causes billions of dollars in lost plant productivity annually. It is an important anthropogenic greenhouse gas, and as a secondary air pollutant, can persist at high concentrations in rural areas far from industrial sources. Ozone reduces plant...

  15. THE EFFECTS OF COMBINED OZONATION AND FILTRATION ON DISINFECTION BY-PRODUCT FORMATION. (R830908)

    EPA Science Inventory

    The effects of combined ozonation and membrane filtration on the removal of the natural organic matter (NOM) and the formation of disinfection by-products (DBPs) were investigated. Ozonation/filtration resulted in a reduction of up to 50% in the dissolved organic carbon (DOC) ...

  16. Evaluation of Aura/OMI Total Column Ozone and Tropospheric Ozone Residual Products using Ozonesonde Profiles from the ARCIONS Campaign

    NASA Astrophysics Data System (ADS)

    Witte, J.; Schoeberl, M.; Thompson, A. M.; Tarasick, D.; Oltmans, S.; Johnson, B.; Davies, J.

    2009-05-01

    During the Arctic Intensive Ozonesonde Network Study (ARCIONS), a large number of sites located over the middle to high latitudes of North America launched daily ozonesondes in the spring (April) and summer (June/July) of 2008. We take advantage of the large number of launches at high northern latitudes to examine the retrieval accuracy of Aura's Ozone Monitoring Instrument (OMI) Total Column Ozone (TCO) and derived Tropospheric Ozone Residual (TOR) products with the equivalent integrated column amounts from ozonesondes with the SBUV/SAGE climatology add-on that estimates the ozone column amounts from the top of the sonde profile to the top of the atmosphere. We find that the OMI TCO and TOR tend to underestimate the sondes for all sites and both seasons. TCO differences between OMI and the sondes are found to be within 10%, while TOR-Sonde differences are observed to be as high as 50% at a number of sites, regardless of latitude and season. TCO amounts from OMI compared to those sonde sites located above 50N are found to be typically over 375 DU in April 2008 while June/July values are clustered around 300-350 DU. Below 50N, OMI-Sonde comparisons show less seasonal separation in total column ozone amounts. Comparisons between the TOR product and sonde integrated tropospheric column (ITC) show no apparent difference between spring and summer. Large differences in troposphere amounts occur even though tropopause heights compare to within just a few percent. Evaluation of the stratospheric column amounts between the ARCIONS sondes and Aura's Microwave Limb Sounder instrument may also be presented. Further investigation into a preliminary method of improving the TOR product using sondes as a validation source shows promise, particularly at high latitudes.

  17. 40 CFR 75.75 - Additional ozone season calculation procedures for special circumstances.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING NOX Mass Emissions Provisions... lbs/mmBtu) shall do so by dividing ozone season NOX mass emissions(in lbs) determined in...

  18. 40 CFR 75.75 - Additional ozone season calculation procedures for special circumstances.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING NOX Mass Emissions Provisions... lbs/mmBtu) shall do so by dividing ozone season NOX mass emissions(in lbs) determined in...

  19. 40 CFR 75.75 - Additional ozone season calculation procedures for special circumstances.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING NOX Mass Emissions Provisions... lbs/mmBtu) shall do so by dividing ozone season NOX mass emissions(in lbs) determined in...

  20. 40 CFR 75.75 - Additional ozone season calculation procedures for special circumstances.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING NOX Mass Emissions Provisions... lbs/mmBtu) shall do so by dividing ozone season NOX mass emissions(in lbs) determined in...

  1. 40 CFR 75.75 - Additional ozone season calculation procedures for special circumstances.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING NOX Mass Emissions Provisions... lbs/mmBtu) shall do so by dividing ozone season NOX mass emissions(in lbs) determined in...

  2. Indoor secondary pollutants from cleaning product and air freshener use in the presence of ozone

    NASA Astrophysics Data System (ADS)

    Singer, Brett C.; Coleman, Beverly K.; Destaillats, Hugo; Hodgson, Alfred T.; Lunden, Melissa M.; Weschler, Charles J.; Nazaroff, William W.

    This study investigated the formation of secondary pollutants resulting from household product use in the presence of ozone. Experiments were conducted in a 50-m 3 chamber simulating a residential room. The chamber was operated at conditions relevant to US residences in polluted areas during warm-weather seasons: an air exchange rate of 1.0 h -1 and an inlet ozone concentration of approximately 120 ppb, when included. Three products were used in separate experiments. An orange oil-based degreaser and a pine oil-based general-purpose cleaner were used for surface cleaning applications. A plug-in scented-oil air freshener (AFR) was operated for several days. Cleaning products were applied realistically with quantities scaled to simulate residential use rates. Concentrations of organic gases and secondary organic aerosol from the terpene-containing consumer products were measured with and without ozone introduction. In the absence of reactive chemicals, the chamber ozone level was approximately 60 ppb. Ozone was substantially consumed following cleaning product use, mainly by homogeneous reaction. For the AFR, ozone consumption was weaker and heterogeneous reaction with sorbed AFR-constituent VOCs was of similar magnitude to homogeneous reaction with continuously emitted constituents. Formaldehyde generation resulted from product use with ozone present, increasing indoor levels by the order of 10 ppb. Cleaning product use in the presence of ozone generated substantial fine particle concentrations (more than 100 μg m -3) in some experiments. Ozone consumption and elevated hydroxyl radical concentrations persisted for 10-12 h following brief cleaning events, indicating that secondary pollutant production can persist for extended periods.

  3. Evidence for an unidentified ground-level source of formaldehyde in the Po Valley with potential implications for ozone production

    NASA Astrophysics Data System (ADS)

    Kaiser, J.; Wolfe, G. M.; Bohn, B.; Broch, S.; Fuchs, H.; Ganzeveld, L. N.; Gomm, S.; Häseler, R.; Hofzumahaus, A.; Holland, F.; Jäger, J.; Li, X.; Lohse, I.; Lu, K.; Rohrer, F.; Wegener, R.; Mentel, T. F.; Kiendler-Scharr, A.; Wahner, A.; Keutsch, F. N.

    2014-10-01

    Ozone concentrations in the Po Valley of Northern Italy often exceed international regulations. As both a source of radicals and an intermediate in the oxidation of most volatile organic compounds (VOCs), formaldehyde (HCHO) is a useful tracer for the oxidative processing of hydrocarbons that leads to ozone production. We investigate the sources of HCHO in the Po Valley using vertical profile measurements acquired from the airship Zeppelin NT over an agricultural region during the PEGASOS 2012 campaign. Using a 1-D model, the total VOC oxidation rate is examined and discussed in the context of formaldehyde and ozone production in the early morning. While model and measurement discrepancies in OH reactivity are small (on average 3.4±11%), HCHO concentrations are underestimated by as much as 1.5 ppb (45%) in the convective mixed layer. A similar underestimate in HCHO was seen in the 2002-2003 FORMAT Po-Valley measurements, though the additional source of HCHO was not identified. Oxidation of unmeasured VOC precursors cannot explain the missing HCHO source, as measured OH reactivity is explained by measured VOCs and their calculated oxidation products. We conclude that local direct emissions from agricultural land are the most likely source of missing HCHO. Model calculations demonstrate that radicals from degradation of this non-photochemical HCHO source increase model ozone production rates by as much as 0.7 ppb h-1 (10%) before noon.

  4. Nimbus-7 Total Ozone Mapping Spectrometer (TOMS) Data Products User`s Guide

    SciTech Connect

    Mcpeters, R.D.; Bhartia, P.K.; Krueger, A.J.; Herman, J.R.; Schlesinger, B.M.; Wellemeyer, C.G.; Seftor, C.J.; Jaross, G.; Taylor, S.L.; Swissler, T.

    1996-04-01

    Two data products from the Total Ozone Mapping Spectrometer (TOMS) onboard Nimbus-7 have been archived at the Distributed Active Archive Center, in the form of Hierarchical Data Format files. The instrument measures backscattered Earth radiance and incoming solar irradiance; their ratio is used in ozone retrievals. Changes in the instrument sensitivity are monitored by a spectral discrimination technique using measurements of the intrinsically stable wavelength dependence of derived surface reflectivity. The algorithm to retrieve total column ozone compares measured Earth radiances at sets of three wavelengths with radiances calculated for different total ozone values, solar zenith angles, and optical paths. The initial error in the absolute scale for TOMS total ozone is 3 percent, the one standard deviation random error is 2 percent, and drift is less than 1.0 percent per decade. The Level-2 product contains the measured radiances, the derived total ozone amount, and reflectivity information for each scan position. The Level-3 product contains daily total ozone amount and reflectivity in a 1 - degree latitude by 1.25 degrees longitude grid. The Level-3 product also is available on CD-ROM. Detailed descriptions of both HDF data files and the CD-ROM product are provided.

  5. Nimbus-7 Total Ozone Mapping Spectrometer (TOMS) Data Products User's Guide

    NASA Technical Reports Server (NTRS)

    McPeters, Richard D.; Bhartia, P. K.; Krueger, Arlin J.; Herman, Jay R.; Schlesinger, Barry M.; Wellemeyer, Charles G.; Seftor, Colin J.; Jaross, Glen; Taylor, Steven L.; Swissler, Tom; Torres, Omar; Labow, Gordon; Byerly, William; Cebula, Richard P.

    1996-01-01

    Two data products from the Total Ozone Mapping Spectrometer (TOMS) onboard Nimbus-7 have been archived at the Distributed Active Archive Center, in the form of Hierarchical Data Format files. The instrument measures backscattered Earth radiance and incoming solar irradiance; their ratio is used in ozone retrievals. Changes in the instrument sensitivity are monitored by a spectral discrimination technique using measurements of the intrinsically stable wavelength dependence of derived surface reflectivity. The algorithm to retrieve total column ozone compares measured Earth radiances at sets of three wavelengths with radiances calculated for different total ozone values, solar zenith angles, and optical paths. The initial error in the absolute scale for TOMS total ozone is 3 percent, the one standard deviation random error is 2 percent, and drift is less than 1.0 percent per decade. The Level-2 product contains the measured radiances, the derived total ozone amount, and reflectivity information for each scan position. The Level-3 product contains daily total ozone amount and reflectivity in a I - degree latitude by 1.25 degrees longitude grid. The Level-3 product also is available on CD-ROM. Detailed descriptions of both HDF data files and the CD-ROM product are provided.

  6. Development of a portable instrument to measure ozone production rates in the troposphere

    NASA Astrophysics Data System (ADS)

    Sklaveniti, Sofia; Locoge, Nadine; Stevens, Philip; Kumar, Vinod; Sinha, Vinayak; Dusanter, Sébastien

    2015-04-01

    Ground-level ozone is a key species related to air pollution, causing respiratory problems, damaging crops and forests, and affecting the climate. Our current understanding of the tropospheric ozone-forming chemistry indicates that net ozone production occurs via reactions of peroxy radicals (HO2 + RO2) with NO producing NO2, whose photolysis leads to O3 formation. Production rates of tropospheric ozone, P(O3), depend on concentrations of oxides of nitrogen (NOx = NO + NO2) and Volatile Organic Compounds (V OCs), but also on production rates of ROx radicals (OH + HO2 + RO2). The formation of ozone follows a complex nonlinear chemistry that makes strategies for reducing ozone difficult to implement. In this context, atmospheric chemistry models are used to develop emission regulations, but there are still uncertainties associated with the chemical mechanisms used in these models. Testing the ozone formation chemistry in atmospheric models is needed, in order to ensure the development of effective strategies for ozone reduction. We will present the development of an instrument for direct measurements of ozone production rates (OPR) in ambient air. The OPR instrument is made of three components: (i) two quartz flow tubes to sample ambient air, one exposed to solar radiation and one covered by a UV filter, (ii) a NO2-to-O3 conversion unit, and (iii) an ozone analyzer. The total amount of ozone exiting each flow tube is conserved in the form of Ox = NO2 + O3. Ozone production rates P(O3) are derived from the difference in Ox concentration between the two flow tubes, divided by the exposure time of air inside the flow tubes. We will present studies that were carried out in the laboratory to characterize each part of the instrument and we will discuss the performances of the OPR instrument based on experiments carried out using synthetic air mixtures of known composition (NOx and V OCs). Chemical modeling will also be presented to assess the reliability of ozone

  7. Ozonation and peroxone oxidation of ethylenethiourea in water: operational parameter optimization and by-product identification.

    PubMed

    Bottrel, S; Amorim, C; Ramos, V; Romão, G; Leao, M

    2015-01-01

    The objective of this work was to study the degradation and mineralization of ethylenethiourea (ETU) in water by ozonation at different pH values and in the presence of hydrogen peroxide. Degradation experiments were performed using an initial ETU concentration of 50 ppm for 180 min with a gas flux of 0.25 dm(3) min(-1) and an O3 production rate of 12.1 mg min(-1). Degradation of by-products was monitored by direct injection electrospray ionization mass spectrometry (ESI-MS), ETU concentration was determined by HPLC-UV, and its mineralization was detected by total organic carbon (TOC) analysis. Optimum degradation of ETU in water was observed at pH = 11, whereas at pH = 3, the degradation of ETU was slowest, indicating that the reaction occurred through different mechanisms. The additional effects of hydroxyl radicals formed at the highest pH can be used to explain the results obtained in this study. Peroxone experiments were carried out in the presence of 400 and 800 mg L(-1) H2O2; the degradation of ETU was faster at 400 mg L(-1) H2O2. This was attributed to the scavenging effect of the excess H2O2. ETU treatment by ozonation produced several by-products of degradation such as ethylene urea and 2-imidazoline. PMID:25256586

  8. Earth Probe Total Ozone Mapping Spectrometer (TOMS) Data Product User's Guide

    NASA Technical Reports Server (NTRS)

    McPeters, R.; Bhartia, P. K.; Krueger, A.; Herman, J.; Wellemeyer, C.; Seftor, C.; Jaross, G.; Torres, O.; Moy, L.; Labow, G.; Byerly, W.; Taylor, S.; Swissler, T.; Cebula, R.

    1998-01-01

    Two data products from the Earth Probe Total Ozone Mapping Spectrometer (EP/TOMS) have been archived at the Distributed Active Archive Center, in the form of Hierarchical Data Format files. The EP/ TOMS began taking measurements on July 15, 1996. The instrument measures backscattered Earth radiance and incoming solar irradiance; their ratio is used in ozone retrievals. Changes in the reflectivity of the solar diffuser used for the irradiance measurement are monitored using a carousel of three diffusers, each exposed to the degrading effects of solar irradiation at different rates. The algorithm to retrieve total column ozone compares measured Earth radiances at sets of three wavelengths with radiances calculated for different total ozone values. The initial error in the absolute scale for TOMS total ozone is 3 percent, the one standard deviation random error is 2 percent, and the drift is less than 0.5 percent over the first year of data. The Level-2 product contains the measured radiances, the derived total ozone amount, and reflectivity information for each scan position. The Level-3 product contains daily total ozone and reflectivity in a 1-degree latitude by 1.25 degrees longitude grid. Level-3 files containing estimates of LTVB at the Earth surface and tropospheric aerosol information are also available, Detailed descriptions of both HDF data-files and the CD-ROM product are provided.

  9. IDENTIFICATION OF NEW DRINKING WATER DISINFECTION BY-PRODUCTS FROM OZONE, CHLORINE DIOXIDE, CHLORAMINE, AND CHLORINE

    EPA Science Inventory

    Due to concern over the potential adverse health effects of trihalomethanes (THMs) and other chlorinated by-products in chlorinated drinking water, alternative disinfection methods are being explored. Ozone, chlorine dioxide, and chloramine are currently popular alternatives to ...

  10. Efficiency and products investigations on the ozonation of 2-methylisoborneol in drinking water.

    PubMed

    Qi, Fei; Xu, Bingbing; Chen, Zhonglin; Ma, Jun; Sun, Dezhi; Zhang, Liqiu

    2009-12-01

    2-Methylisobomeol (MIB) is a terpenoid produced as a secondary metabolite by some cyanobacteria and actinomycetes and thus can be present in some drinking water source waters. The removal efficiency, products, and degradation pathway of MIB in drinking water by ozonation were studied. The results showed that ozone is efficient in removing MIB from an aqueous solution, regardless of the initial MIB concentration. Hydroxyl radicals (OH) scavenger experiments indicated that hydroxyl radicals are involved in MIB degradation. The degradation products of MIB were identified by gas chromatography-mass spectrometry. Camphor was identified as a primary degradation product, which was further oxidized to form other degradation intermediates, such as aldehydes, ketones, and carboxylic acids. A possible degradation pathway for the ozonation of MIB was proposed. Qualitative and quantitative analysis of the formation of aldehydes was carried out. It was found that six aldehydes are the main aldehydes products of ozonation of MIB, namely formaldehyde, acetaldehyde, propanal, butanal, glyoxal, and methyl glyoxal. PMID:20099625

  11. EXAMINING THE INFLAMMATORY RESPONSES OF HAPS: THE ROLE OF OZONE AND OTHER PHTOTCHEMICAL TRANSFORMATION PRODUCTS

    EPA Science Inventory

    The chemistry and health effects of individual hazardous air pollutants (HAPS) have been studied for many years. Once released into the atmosphere, HAPS interact with hydroxyl radicals and ozone (created by photochemical processes), to produce many different products, whose toxic...

  12. LABORATORY AND COMPUTATIONAL INVESTIGATIONS OF THE ATMOSPHERIC CHEMISTRY OF KEY OXIDATION PRODUCTS CONTROLLING TROPOSPHERIC OZONE FORMATION

    EPA Science Inventory

    Major uncertainties remain in our ability to identify the key reactions and primary oxidation products of volatile hydrocarbons that contribute to ozone formation in the troposphere. To reduce these uncertainties, computational chemistry, mechanistic and process analysis techniqu...

  13. Effects of ozone treatment on Botrytis cinerea and Sclerotinia sclerotiorum in relation to horticultural product quality.

    PubMed

    Sharpe, Deana; Fan, Lihua; McRae, Ken; Walker, Brad; MacKay, Ron; Doucette, Craig

    2009-08-01

    Botrytis cinerea and Sclerotinia sclerotiorum are fungal pathogens that cause the decay of many fruits and vegetables. Ozone may be used as an antimicrobial agent to control the decay. The effect of gaseous ozone on spore viability of B. cinerea and mycelial growth of B. cinerea and S. sclerotiorum were investigated. Spore viability of B. cinerea was reduced by over 99.5% (P < 0.01) and height of the aerial mycelium was reduced from 4.7 mm in the control to less than 1 mm after exposure to 450 or 600 ppb ozone for 48 h at 20 degrees C. Sporulation of B. cinerea was also substantially inhibited by ozone treatments. However, ozone had no significant effect on mycelial growth of S. sclerotiorum in vitro. Decay and quality parameters including color, chlorophyll fluorescence (CF), and ozone injury were further assessed for various horticultural commodities (apple, grape, highbush blueberry, and carrot) treated with 450 ppb of ozone for 48 h at 20 degrees C over a period of 12 d. Lesion size and height of the aerial mycelium were significantly reduced by the ozone treatment on carrots inoculated with mycelial agar plugs of B. cinerea or S. sclerotiorum. Lesion size was also reduced on treated apples inoculated with 5 x 10(6) spores/mL of B. cinerea, and decay incidence of treated grapes was reduced. The 450 ppb ozone for 48 h treatment had no significant effect on color of carrots and apples or on CF of apples and grapes. Ozone, an environmentally sound antimicrobial agent, inactivates microorganisms through oxidization and residual ozone spontaneously decomposes to nontoxic products. It may be applied to fruits and vegetables to reduce decay and extend shelf life. PMID:19723209

  14. An Improved Tropospheric Ozone Residual Product: Limitations and Applications

    NASA Astrophysics Data System (ADS)

    Witte, J. C.; Douglass, A. R.; Olsen, M. A.; Thompson, A. M.

    2012-12-01

    The Tropospheric Ozone Residual (TOR) product is derived from Aura's Ozone (O3) Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS). OMI and MLS can estimate the TOR by subtracting the MLS stratospheric O3 from the OMI total column O3. Our improved TOR is a subset of the 2005-2012 database that takes into account (1) outliers that occur regularly in the mid to high latitudes, and (2) decreased sensitivity in the OMI O3 total column below clouds that contributes to a low-bias in the TOR compared to in-situ ozonesonde observations. To remove outliers, we have devised a filtering criteria based on the expected range of tropospheric O3 values from sondes, in combination with the tropospheric column fraction amount represented by the ratio of the OMI total column O3 to the MLS stratospheric column amount. We take advantage of a new cloud height algorithm - the optical centroid cloud pressure algorithm (OCCP) - that is sensitive to O3 below the nominal cloud-top pressure and can extend significantly below previous estimates of the assigned effective cloud height. Applying the new algorithm significantly improves the agreement with sondes for effective cloud pressures greater than 800-850 hPa, thereby reducing the need to assign a below-cloud O3 climatology. Finally, we assess the viability of applying the improved TOR for pollution studies and monitoring in the northern mid-latitudes. We examine O3 variability in the improved TOR over case study regions of Europe, Southeast Asia, and the US between 2005 and 2012, along with available sonde observations. We record the frequency, dates, and locations of the best and worst agreements with sondes to estimate when and where the TOR can be optimally used, and show cases where the variability of the TOR is representative of O3 variability in the boundary layer. A potential application of the improved TOR is to study inter-annual variability in summertime continental pollution outflow over regions of the US and

  15. Production of single- and double-strand breaks in plasmid DNA by ozone

    SciTech Connect

    Hamelin, C.

    1985-02-01

    Agarose gel electrophoresis and electron microscopy were used to determine the type of lesions produced in DNA by ozone. This strong oxidizing agent was found to relax, linearize, then degrade native plasmid (pAT153) DNA molecules in solution. Ozone, like ionizing radiation, thus produced DNA breakage. To ascertain this point, wild-type and radiosensitive strains of Escherichia coli were transfected with control or ozonated plasmid DNA, and the host cells were selected for antibiotic resistance. A significant reduction in the transforming ability of pAT153 was observed following ozonation. Mutants deficient in the repair of DNA single-strand breaks yielded less ampicillin- or tetracycline-resistant clones than repair-proficient strains. In E. coli, the same gene products are probably involved in the repair of both radiation- and ozone-induced DNA breaks.

  16. Application of catalytic ozone chemistry for improving biodiesel product performance.

    PubMed

    Baber, Tylisha M; Graiver, Daniel; Lira, Carl T; Narayan, Ramani

    2005-01-01

    Ozonolysis of methyl soyate (biodiesel) was conducted in the presence of methanol, dichloromethane (solvent), and triethylamine (catalyst) at -75 degrees C. Structural analysis, including FTIR, GC, and GC-MS, showed that the total amount of double bonds in the mixture was reduced by more than 90% after 2 h of ozonolysis. All of the esters predicted by this novel application of ozone reaction chemistry were successfully produced. Other major components were identified by GC-MS. Thermogravimetric analysis showed a dramatic decrease in the onset volatilization temperature from 135 to 73 degrees C, making ozonated biodiesel fuel comparable to diesel fuel (76 degrees C). Differential scanning calorimetric studies showed that the cooling curves for both methyl soyate and ozonated methyl soyate displayed two exothermic regions. The onset freezing temperature of ozonated methyl soyate in the "colder" region was significantly reduced from -63 to -86 degrees C. Furthermore, the degree of crystallinity in the "hotter" region was also reduced. PMID:15877350

  17. Ozone Production and Loss Rate Measurements in the Middle Stratosphere

    NASA Technical Reports Server (NTRS)

    Jucks, Kenneth W.; Johnson, David G.; Chance, K. V.; Traub, Wesley A.; Salawitch, R. J.; Stachnik, R. A.

    1996-01-01

    The first simultaneous measurements of HO(x), NO(x), and Cl(x) radicals in the middle stratosphere show that NO(x) catalytic cycles dominate loss of ozone (O3) for altitudes between 24 and 38 km; Cl(x) catalytic cycles are measured to be less effective than previously expected; and there is no 'ozone deficit' in the photochemically dominated altitude range from 31 and 38 km, contrary to some previous theoretical studies.

  18. The GOME-2 total column ozone product: Retrieval algorithm and ground-based validation

    NASA Astrophysics Data System (ADS)

    Loyola, D. G.; Koukouli, M. E.; Valks, P.; Balis, D. S.; Hao, N.; van Roozendael, M.; Spurr, R. J. D.; Zimmer, W.; Kiemle, S.; Lerot, C.; Lambert, J.-C.

    2011-04-01

    The Global Ozone Monitoring Instrument (GOME-2) was launched on EUMESAT's MetOp-A satellite in October 2006. This paper is concerned with the retrieval algorithm GOME Data Processor (GDP) version 4.4 used by the EUMETSAT Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF) for the operational generation of GOME-2 total ozone products. GDP 4.4 is the latest version of the GDP 4.0 algorithm, which is employed for the generation of official Level 2 total ozone and other trace gas products from GOME and SCIAMACHY. Here we focus on enhancements introduced in GDP 4.4: improved cloud retrieval algorithms including detection of Sun glint effects, a correction for intracloud ozone, better treatment of snow and ice conditions, accurate radiative transfer modeling for large viewing angles, and elimination of scan angle dependencies inherited from Level 1 radiances. Furthermore, the first global validation results for 3 years (2007-2009) of GOME-2/MetOp-A total ozone measurements using Brewer and Dobson measurements as references are presented. The GOME-2/MetOp-A total ozone data obtained with GDP 4.4 slightly underestimates ground-based ozone by about 0.5% to 1% over the middle latitudes of the Northern Hemisphere and slightly overestimates by around 0.5% over the middle latitudes in the Southern Hemisphere. Over high latitudes in the Northern Hemisphere, GOME-2 total ozone has almost no offset relative to Dobson readings, while over high latitudes in the Southern Hemisphere GOME-2 exhibits a small negative bias below 1%. For tropical latitudes, GOME-2 measures on average lower ozone by 0% to 2% compared to Dobson measurements.

  19. Evaluation of the persistence of transformation products from ozonation of trace organic compounds - a critical review.

    PubMed

    Hübner, Uwe; von Gunten, Urs; Jekel, Martin

    2015-01-01

    Ozonation is an efficient treatment system to reduce the concentration of trace organic compounds (TrOCs) from technical aquatic systems such as drinking water, wastewater and industrial water, etc. Although it is well established that ozonation generally improves the removal of organic matter in biological post-treatment, little is known about the biodegradability of individual transformation products resulting from ozonation of TrOCs. This publication provides a qualified assessment of the persistence of ozone-induced transformation products based on a review of published product studies and an evaluation of the biodegradability of transformation products with the biodegradability probability program (BIOWIN) and the University of Minnesota Pathway Prediction System (UM-PPS). The oxidation of TrOCs containing the four major ozone-reactive sites (olefins, amines, aromatics and sulfur-containing compounds) follows well described reaction pathways leading to characteristic transformation products. Assessment of biodegradability revealed a high sensitivity to the formed products and hence the ozone-reactive site present in the target compound. Based on BIOWIN, efficient removal can be expected for products from cleavage of olefin groups and aromatic rings. In contrast, estimations and literature indicate that hydroxylamines and N-oxides, the major products from ozonation of secondary and tertiary amines are not necessarily better removed in biological post-treatment. According to UM-PPS, degradation of these products might even occur via reformation of the corresponding amine. Some product studies with sulfide-containing TrOCs showed a stoichiometric formation of sulfoxides from oxygen transfer reactions. However, conclusions on the fate of transformation products in biological post-treatment cannot be drawn based on BIOWIN and UM-PPS. PMID:25462725

  20. Development and field deployment of an instrument to measure ozone production rates in the troposphere

    NASA Astrophysics Data System (ADS)

    Sklaveniti, S.; Locoge, N.; Dusanter, S.; Leonardis, T.; Lew, M.; Bottorff, B.; Sigler, P. S. R.; Stevens, P. S.; Wood, E. C. D.; Kundu, S.; Gentner, D. R.

    2015-12-01

    Ozone is a greenhouse gas and a primary constituent of urban smog, irritating the respiratory system and damaging the vegetation. The current understanding of ozone chemistry in the troposphere indicates that net ozone production P(O3) occurs when peroxy radicals (HO2+RO2) react with NO producing NO2, whose photolysis leads to O3 formation. P(O3) values can be calculated from peroxy radical concentrations, either from ambient measurements or box model outputs. These two estimation methods often disagree for NOx mixing ratios higher than a few ppb, questioning our ability to measure peroxy radicals under high NOx conditions or indicating that there are still unknowns in our understanding of the radical and ozone production chemistry. Direct measurements of ozone production rates will help to address this issue and improve air quality regulations. We will present the development of an instrument for direct measurements of ozone production rates (OPR). The OPR instrument consists of three parts: (i) two quartz flow tubes sampling ambient air ("Ambient" and "Reference" flow tube), (ii) an O3-to-NO2 conversion unit, and (iii) a Cavity Attenuated Phase Shift (CAPS) monitor to measure NO2. The air in the Ambient flow tube undergoes the same photochemistry as in ambient air, while the Reference flow tube is covered by a UV filter limiting the formation of ozone. Exiting the flow tubes, ozone is converted into NO2 and the sum O3+NO2 (Ox) is measured by the CAPS monitor. The difference in Ox between the two flow tubes divided by the residence time yields the Ox production rate, P(Ox). P(O3) is assumed to be equal to P(Ox) when NO2 is efficiently photolyzed during daytime. We will present preliminary results from the Indiana Radical, Reactivity and Ozone Production Intercomparison (IRRONIC) campaign in Bloomington, Indiana, during July 2015, where ozone production rates were measured by introducing various amounts of NO inside the flow tubes to investigate the ozone

  1. Ozonation of wastewater: removal and transformation products of drugs of abuse.

    PubMed

    Rodayan, Angela; Segura, Pedro Alejandro; Yargeau, Viviane

    2014-07-15

    In this study amphetamine, methamphetamine, methylenedioxymethamphetamine (MDMA), cocaine (COC), benzoylecgonine (BE), ketamine (KET) and oxycodone (OXY) in wastewater at concentrations of 100 μgL(-1) were subjected to ozone to determine their removals as a function of ozone dose and to identify significant oxidation transformation products (OTPs) produced as a result of ozonation. A method based on high resolution mass spectrometry and differential analysis was used to facilitate and accelerate the identification and structural elucidation of the transformation products. The drug removal ranged from 3 to 50% depending on the complexity of the matrix and whether a mixture or individual drugs were ozonated. Both transient and persistent oxidation transformation products were identified for MDMA, COC and OXY and their chemical formulae were determined. Three possible structures of the persistent transformation product of MDMA (OTP-213) with chemical formula C10H16O4N, were determined based on MS(n) mass spectra and the most plausible structure (OTP-213a) was determined based on the chemistry of ozone. These results indicate that ozone is capable of removing drugs of abuse from wastewater to varying extents and that persistent transformation products are produced as a result of treatment. PMID:24315025

  2. Characterization of surface dielectric barrier discharge influenced by intermediate frequency for ozone production

    NASA Astrophysics Data System (ADS)

    Abdelaziz, Ayman A.; Ishijima, Tatsuo; Seto, Takafumi; Osawa, Naoki; Wedaa, Hassan; Otani, Yoshio

    2016-06-01

    The aim of this study is to investigate the effect of the intermediate frequency (1–10 kHz) of the sinusoidal driving voltage on the characteristics of a developed surface dielectric barrier discharge (SDBD)-based reactor having spikes on its discharge electrode. Moreover, its influence on the production of ozone and nitrogen oxide byproducts is evaluated. The results show that SDBD is operated in the filamentary mode at all the frequencies. Nevertheless, the pulses of the discharge current at high frequencies are much denser and have higher amplitudes than those at low frequencies. The analysis of the power consumed in the reactor shows that a small portion of the input power is dissipated in the dielectric material of SDBD source, whereas the major part of the power is consumed in the plasma discharge. The results of the ozone production show that higher frequencies have a slightly adverse effect on the ozone production at relatively high energy density values, where the ozone concentration is slightly decreased when the frequency is increased at the same energy density. The temperature of the discharge channels and gas is not a crucial factor for the decomposition of ozone in this reactor, while the results of the measurements of nitrogen oxides characteristics indicate that the formation of NO and NO2 has a significant adverse effect on the production efficiency of ozone due to their oxidation to another nitrogen oxides and their catalytic effect.

  3. Ozone production efficiency calculated for different cities in North China

    NASA Astrophysics Data System (ADS)

    Xue, Min; Ma, Jianzhong

    2014-05-01

    North China, or Huabei in Chinese, is one of the most severely polluted regions in China. There are many large, complex and strong emission sources in Beijing, Tianjin and Tangshan (together called Jing-Jin-Tang in Chinese) and other urban and industrial centers in Huabei. We applied a regional chemical transport model including the tracer-tagging technique to investigate the chemical characteristics of air masses from different pollution hotspots in Huabei during the IPAC-NC campaign in spring 2006. We calculated the ozone production efficiency of NOx (OPEx) using selected data points of Ox and NOz corresponding to a large number of model grids, which have a good representation of the chemical characteristics of air masses for an entire investigated region. The estimated OPEx for Beijing, Tianjin, Tangshan, and Shijiazhuang general plumes is 3.35, 2.75, 1.43 and 2.33 mole/mole, respectively. We also calculated the OPEx using selected data points of Ox and NOz corresponding to different air masses arriving at Xin'an (one model grid), a rural station located in the center part of Jing-Jin-Tang. The estimated OPEx in Beijing, Tianjin, and Tangshan air masses arriving at Xin'an is 2.98, 2.52, and 1.42 mole/mole, respectively. The difference in estimated OPEx can be attributed to the difference in the emission source types and strength between these regions. The estimated OPEx in Beijing, Tianjin and Tangshan air masses arriving at Xin'an are comparable to those in their general pollution plumes. This indicates that air masses from different urban and industrial centers in Huabei can also maintain their different chemical characteristics while being transported to the rural areas.

  4. Nimbus-7 Total Ozone Mapping Spectrometer (TOMS) data products user's guide

    NASA Technical Reports Server (NTRS)

    Mcpeters, Richard D.; Krueger, Arlin J.; Bhartia, P. K.; Herman, Jay R.; Oaks, Arnold; Ahmad, Ziuddin; Cebula, Richard P.; Schlesinger, Barry M.; Swissler, Tom; Taylor, Steven L.

    1993-01-01

    Two tape products from the Total Ozone Mapping Spectrometer (TOMS) aboard the Nimbus-7 have been archived at the National Space Science Data Center. The instrument measures backscattered Earth radiance and incoming solar irradiance; their ratio -- the albedo -- is used in ozone retrievals. In-flight measurements are used to monitor changes in the instrument sensitivity. The algorithm to retrieve total column ozone compares the observed ratios of albedos at pairs of wavelengths with pair ratios calculated for different ozone values, solar zenith angles, and optical paths. The initial error in the absolute scale for TOMS total ozone is 3 percent, the one standard-deviation random error is 2 percent, and the drift is +/- 1.5 percent over 14.5 years. The High Density TOMS (HDTOMS) tape contains the measured albedos, the derived total ozone amount, reflectivity, and cloud-height information for each scan position. It also contains an index of SO2 contamination for each position. The Gridded TOMS (GRIDTOMS) tape contains daily total ozone and reflectivity in roughly equal area grids (110 km in latitude by about 100-150 km in longitude). Detailed descriptions of the tape structure and record formats are provided.

  5. Photochemical production of ozone in the upper troposphere in association with cumulus convection over Indonesia

    NASA Astrophysics Data System (ADS)

    Kita, K.; Kawakami, S.; Miyazaki, Y.; Higashi, Y.; Kondo, Y.; Nishi, N.; Koike, M.; Blake, D. R.; Machida, T.; Sano, T.; Hu, W.; Ko, M.; Ogawa, T.

    2003-02-01

    The Biomass Burning and Lightning Experiment phase A (BIBLE-A) aircraft observation campaign was conducted from 24 September to 10 October 1998, during a La Niña period. During this campaign, distributions of ozone and its precursors (NO, CO, and nonmethane hydrocarbons (NMHCs)) were observed over the tropical Pacific Ocean, Indonesia, and northern Australia. Mixing ratios of ozone and its precursors were very low at altitudes between 0 and 13.5 km over the tropical Pacific Ocean. The mixing ratios of ozone precursors above 8 km over Indonesia were often significantly higher than those over the tropical Pacific Ocean, even though the prevailing easterlies carried the air from the tropical Pacific Ocean to over Indonesia within several days. For example, median NO and CO mixing ratios in the upper troposphere were 12 parts per trillion (pptv) and 72 parts per billion (ppbv) over the tropical Pacific Ocean and were 83 pptv and 85 ppbv over western Indonesia, respectively. Meteorological analyses and high ethene (C2H4) mixing ratios indicate that the increase of the ozone precursors was caused by active convection over Indonesia through upward transport of polluted air, mixing, and lightning all within the few days prior to observation. Sources of ozone precursors are discussed by comparing correlations of some NMHCs and CH3Cl concentrations with CO between the lower and upper troposphere. Biomass burning in Indonesia was nearly inactive during BIBLE-A and was not a dominant source of the ozone precursors, but urban pollution and lightning contributed importantly to their increases. The increase in ozone precursors raised net ozone production rates over western Indonesia in the upper troposphere, as shown by a photochemical model calculation. However, the ozone mixing ratio (~20 ppbv) did not increase significantly over Indonesia because photochemical production of ozone did not have sufficient time since the augmentation of ozone precursors. Backward trajectories

  6. Photochemical production of ozone in the upper troposphere in association with cumulus convection over Indonesia

    NASA Astrophysics Data System (ADS)

    Kita, K.; Kawakami, S.; Miyazaki, Y.; Higashi, Y.; Kondo, Y.; Nishi, N.; Koike, M.; Blake, D. R.; Machida, T.; Sano, T.; Hu, W.; Ko, M.; Ogawa, T.

    2002-02-01

    The Biomass Burning and Lightning Experiment phase A (BIBLE-A) aircraft observation campaign was conducted from 24 September to 10 October 1998, during a La Niña period. During this campaign, distributions of ozone and its precursors (NO, CO, and nonmethane hydrocarbons (NMHCs)) were observed over the tropical Pacific Ocean, Indonesia, and northern Australia. Mixing ratios of ozone and its precursors were very low at altitudes between 0 and 13.5 km over the tropical Pacific Ocean. The mixing ratios of ozone precursors above 8 km over Indonesia were often significantly higher than those over the tropical Pacific Ocean, even though the prevailing easterlies carried the air from the tropical Pacific Ocean to over Indonesia within several days. For example, median NO and CO mixing ratios in the upper troposphere were 12 parts per trillion (pptv) and 72 parts per billion (ppbv) over the tropical Pacific Ocean and were 83 pptv and 85 ppbv over western Indonesia, respectively. Meteorological analyses and high ethene (C2H4) mixing ratios indicate that the increase of the ozone precursors was caused by active convection over Indonesia through upward transport of polluted air, mixing, and lightning all within the few days prior to observation. Sources of ozone precursors are discussed by comparing correlations of some NMHCs and CH3Cl concentrations with CO between the lower and upper troposphere. Biomass burning in Indonesia was nearly inactive during BIBLE-A and was not a dominant source of the ozone precursors, but urban pollution and lightning contributed importantly to their increases. The increase in ozone precursors raised net ozone production rates over western Indonesia in the upper troposphere, as shown by a photochemical model calculation. However, the ozone mixing ratio (˜20 ppbv) did not increase significantly over Indonesia because photochemical production of ozone did not have sufficient time since the augmentation of ozone precursors. Backward trajectories

  7. Ozone Effects on Global Net Primary Production and Carbon Sequestration Using a Biogeochemistry Model

    NASA Astrophysics Data System (ADS)

    Felzer, B. S.; Kicklighter, D. W.; Melillo, J. M.; Wang, C.; Zhuang, Q.; Prinn, R. G.

    2002-12-01

    The effects of air pollution on vegetation may provide another important control on the carbon cycle that has not yet been widely considered. Prolonged exposure to high levels of ozone, in particular, has been observed to inhibit photosynthesis by direct cellular damage within the leaves and through changes in stomatal conductance. We have incorporated simple empirical equations derived for hardwoods, pines, and crops into the Terrestrial Ecosystem Model (TEM, version 4.3) to explore spatial and temporal variations of ozone effects on net primary productivity (NPP) and carbon sequestration across the globe. Although our results show up to a 2% reduction in annual NPP as a result of historical ozone levels during the late 1980s-early 1990s, regionally this reduction is much larger. The largest decreases (up to 39% in some locations) occur in the eastern U.S., Europe, and China, during months with high ozone levels and substantial production. Carbon sequestration during the early 1990s is reduced by as much as 0.43 PgC/yr, or 15%, with the presence of ozone. Thus the effects of ozone on net primary production and carbon sequestration should be factored into future calculations of the global carbon budget.

  8. Using back trajectories and process analysis to investigate photochemical ozone production in the Puget Sound region

    NASA Astrophysics Data System (ADS)

    Jiang, Guangfeng; Lamb, Brian; Westberg, Hal

    A photochemical Eulerian grid modeling system, consisting of MM5/CALMET/CALGRID, was modified to include a process analysis scheme, and a back trajectory method using the CALPUFF model in a reverse diffusion mode was implemented to define the air mass transport path reaching a downwind receptor from urban Seattle, WA. Process analysis was used to determine the relative importance of chemical production, advection, diffusion and deposition within the receptor grid cell and also along the air mass transport path from the urban source area to the receptor. This analysis was applied to an ozone episode occurring during 11-14 July 1996, in the Puget Sound region of Washington State. Within the receptor grid, the process analysis showed that ozone concentrations increase during the day as chemical production exceeds the net effects of deposition and vertical diffusion. Concentrations decrease after mid-afternoon when horizontal advection begins to dominate the other processes. When applied along the air mass transport path, process analysis shows that during most of the day, chemical production is larger than the other processes and causes the air mass ozone concentration to steadily increase during transport downwind of the urban core. Maximum ozone production rates equaled 20-25 ppb/h along the trajectory to the rural monitoring site where peak ozone levels occurred approximately 40 km downwind of urban Seattle, WA. The chemical production rates during this ozone evolution process play an important role in the peak ozone values. Higher peak ozone concentrations that occurred on Sunday, 14 July 1996 (118 ppbv), compared to those on Friday, 12 July 1996 (80 ppbv), were due, in part, to the higher ozone production rates along the trajectory to the rural monitoring site on 14 July compared to 12 July. These differences in chemical production appear to be related to differences in VOC/NO x ratios within the urban air mass for each day. The importance of VOC/NO x effects on

  9. Ozone exposure of human tracheal epithelial cells inactivates cyclooxygenase and increases 15-HETE production.

    PubMed

    Alpert, S E; Walenga, R W

    1995-12-01

    We assessed the immediate and prolonged effects of ozone on arachidonic acid (AA) metabolism by primary cultured human tracheal epithelial (TE) cells. TE monolayers were exposed at a gas-fluid interface to air or 0.1, 0.25, or 0.5 ppm ozone (15 min air, then 45 min air/ozone), and serially collected effluents were analyzed by thin-layer chromatography (TLC) and/or high-performance liquid chromatography. Release of prostaglandin E2 (PGE2) and AA, but not 15-hydroxyeicosatetraenoic acid (15-HETE) or its metabolites, was detected from cultures prelabeled with [14C]AA. PGE2 production, measured by immunoassay, was nearly constant during air exposure. In contrast, PGE2 increased two- to threefold during the first 15-min exposure to all concentrations of ozone, but then progressively declined to 78 +/- 17, 57 +/- 12 (P < or = 0.05), and 45 +/- 15% (P < or = 0.05) of air controls after exposure to 0.1, 0.25, and 0.5 ppm ozone. Ozone did not induce a new spectrum of AA metabolites; only PGE2, lesser amounts of PGF2 alpha, and 15-HETE were present in media and cell extracts of air- or ozone-exposed cultures provided with 30 microM exogenous AA. However, cyclooxygenase (CO) activity (PGE2 produced from 30 microM AA) decreased to 82 +/- 9, 53 +/- 8 (P < or = 0.05), and 28 +/- 6% (P < or = 0.05) vs. controls after 0.1, 0.25, and 0.5 ppm ozone, whereas 15-HETE production was unimpaired. When cells exposed to 0.5 ppm ozone were maintained for up to 6 h in 5% CO2-air, spontaneous PGE2 production remained decreased and recovery of CO activity was extremely slow. TLC analysis of lipid extracts from [14C]AA-labeled cells revealed a nearly twofold increase in free intracellular 15-HETE, and hydrolysis of phospholipids demonstrated increased esterified 15-HETE. Exposure of human TE cells to ozone leads to a transient increase followed by prolonged decrease in PGE2 production and increased intracellular retention of 15-HETE. Loss of the bronchodilator and anti-inflammatory properties

  10. 30 CFR 250.803 - Additional production system requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Additional production system requirements. 250... Production Safety Systems § 250.803 Additional production system requirements. (a) For all production platforms, you must comply with the following production safety system requirements, in addition to...

  11. 30 CFR 250.803 - Additional production system requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Additional production system requirements. 250... Production Safety Systems § 250.803 Additional production system requirements. (a) For all production platforms, you must comply with the following production safety system requirements, in addition to...

  12. Additives In Meat and Poultry Products

    MedlinePlus

    ... all cases, ingredients must be listed on the product label in the ingredients statement in order by weight, ... acid pyrophosphate, or orthophosphates, declared as "phosphates" on labels. PROPYL GALLATE - used as an antioxidant to prevent rancidity in products such as rendered fats or pork sausage. It ...

  13. Ozone effects on productivity and diversity of an early successional forest community

    SciTech Connect

    Barbo, D.N.; Chappelka, A.H.; Stolte, K.W.

    1995-06-01

    There has been little research on the effects of tropospheric ozone on diversity and productivity of native understory vegetation and tree species growing in competition. Loblolly pine and an associated early successional forest community was exposed to 4 treatments of ozone. The treatments were: CF=carbon-filtered air, NF=non-filtered 1X air, AA=ambient air and 2X=twice AA air. Pine height and diameter, number of understory species, and percent-cover were measured. First-year results show the number of species were significantly reduced in 2X compared to CF. Blackberry, although severely injured (visible), dominated the 2X treatments. Bahia grass increased in abundance and cover with decreasing ozone, panicum grass increased in abundance and cover with increasing ozone, and andropogon was unaffected. Pine height and diameter was significantly reduced in the CF treatment. This study will continue for at least one more growing season.

  14. Inhalation of ozone produces a decrease in superoxide anion radical production in mouse alveolar macrophages

    SciTech Connect

    Ryer-Powder, J.E.; Amoruso, M.A.; Czerniecki, B.; Witz, G.; Goldstein, B.D.

    1988-11-01

    The potentiation of fatal bacterial pneumonia in mice by prior inhalation of ozone occurs at levels of this oxidant pollutant that are frequently present in ambient air. A likely mechanism for this effect is an ozone-induced inhibition in the ability of pulmonary alveolar macrophages (PAM) to produce superoxide anion radical (O2-) demonstrated in the present study. A 25% decrease in PAM O2- production, as measured by nitroblue tetrazolium reduction, occurred after exposure of Swiss-Webster mice to 0.11 ppm ozone for 3 h (p less than 0.05). After 1 ppm there was almost complete inhibition of O2- release. In contrast, the rat, which is highly resistant to the potentiation of bacterial infections by ozone, was less sensitive to inhibition of PAM O2- production, as measured by cytochrome c reduction (mouse IC50, 0.41 ppm; rat IC50, 3.0 ppm ozone for 3 h). The observed decrement in mouse PAM O2- production was not associated with any change in phagocytic ability, as measured by both latex bead ingestion and 51Cr-labeled sheep red blood cell ingestion. This decrease in O2- production in the presence of normal phagocytic activity is analogous to certain of the findings in the neutrophils of children with chronic granulomatous disease. A decrease in rat PAM membrane cytochrome b558 levels was observed after ozone exposure of 3 ppm for 3 h, preliminarily suggesting that the mechanism by which ozone interferes with PAM O2- production may be through interaction with this heme-containing electron carrier.

  15. Ozone impacts on the productivity of selected crops. [Corn, wheat, soybean and peanut crops

    SciTech Connect

    Heck, W.W.; Cure, W.W.; Shriner, D.S.; Olson, R.J.; Heagle, A.S.

    1982-01-01

    The regional impacts of ozone on corn, wheat, soybean, and peanut crops are estimated by using dose-response functions to relate ambient maximum 7 h/d seasonal ozone concentrations to crop productivity data. Linear dose-response functions were developed from open-top field chamber studies. It was assumed that the limited number of cultivars and growing conditions available for the analysis were representative of major agricultural regions. Hourly ozone data were selected to represent rural concentrations and used to calculate maximum 7-h/d average values. Seasonal ozone averages for counties were extrapolated from approximately 300 monitoring sites. Results must be interpreted with knowledge of these assumptions and sources of uncertainty. Impacts are calculated for county units for the conterminous United States with maps showing patterns and tables summarizing the potential magnitude of ozone effects on selected crop yields. The assessment estimates that approximately three billion dollars of productivity could be gained if current maximum 7 hour per day ozone levels were reduced from present levels to below 25 parts per billion. Dollar values are based on 1978 crop prices, without accounting for price effects, to provide an overall estimate of the impact. Of the estimated economic impact, soybean represents 64%, corn 17%, wheat 12%, and peanuts 7%.

  16. Ozone production in the New York City urban plume

    NASA Astrophysics Data System (ADS)

    Kleinman, Lawrence I.; Daum, Peter H.; Imre, Dan G.; Lee, Jai H.; Lee, Yin-Nan; Nunnermacker, Linda J.; Springston, Stephen R.; Weinstein-Lloyd, Judith; Newman, Leonard

    2000-06-01

    In the summer of 1996 the Department of Energy G-1 aircraft was deployed in the New York City metropolitan area as part of the North American Research Strategy for Tropospheric Ozone-Northeast effort to determine the causes of elevated O3 levels in the northeastern United States. Measurements of O3, O3 precursors, and other photochemically active trace gases were made upwind and downwind of New York City with the objective of characterizing the O3 formation process and its dependence on ambient levels of NOx and volatile organic compounds (VOCs). Four flights are discussed in detail. On two of these flights, winds were from the W-SW, which is the typical direction for an O3 episode. On the other two flights, winds were from the NW, which puts a cleaner area upwind of the city. The data presented include plume and background values of O3, CO, NOx, and NOy concentration and VOC reactivity. On the W-SW flow days O3 reached 110 ppb. According to surface observations the G-1 intercepted the plume close to the region where maximum O3 occurred. At this point the ratio NOx/NOy was 20-30%, indicating an aged plume. Plume values of CO/NOy agree to within 20% with emission estimates from the core of the New York City metropolitan area. Steady state photochemical calculations were performed using observed or estimated trace gas concentrations as constraints. According to these calculations the local rate of O3 production P(O3) in all four plumes is VOC sensitive, sometimes strongly so. The local sensitivity calculations show that a specified fractional decrease in VOC concentration yields a similar magnitude fractional decrease in P(O3). Imposing a decrease in NOx, however, causes P(O3) to increase. The question of primary interest from a regulatory point of view is the sensitivity of O3 concentration to changes in emissions of NOx and VOCs. A qualitative argument is given that suggests that the total O3 formed in the plume, which depends on the entire time evolution of the

  17. Fate of three anti-influenza drugs during ozonation of wastewater effluents - degradation and formation of transformation products.

    PubMed

    Fedorova, Ganna; Grabic, Roman; Nyhlen, Jonas; Järhult, Josef D; Söderström, Hanna

    2016-05-01

    Anti-influenza drugs constitute a key component of pandemic preparedness plans against influenza. However, the occurrence of such drugs in water environments, the potential of resistance development in the natural hosts, and the risk for transmission of antiviral resistance to humans call for measures to increase removal in wastewater treatment plants (WWTPs). In this study, removal of three anti-influenza drugs; amantadine (AM), oseltamivir carboxylate (OC) and zanamivir (ZA), and formation/removal of their transformation products during ozonation of wastewater effluents from two Swedish WWTPs in Uppsala and Stockholm were studied. The removal profile of target antivirals and formation/removal of their transformation products were studied by liquid chromatography/high resolution mass spectrometry. 3.5 h of ozone exposure (total dose of ozone 5.95 g) led to complete removal of the three anti-influenza drugs with a degradation in the following order ZA > OC > AM. Two, five and one transformation products were identified and semi-quantified for AM, OC and ZA, respectively. Increasing and later decreasing transformation products concentration followed the decrease in concentration of target compounds. All transformation products detected, except one of AM in wastewater from Stockholm WWTP, were removed at the end of the experiment. The removal efficiency was higher for all studied compounds in wastewater from Uppsala WWTP, which had lower TOC and COD values, less phosphorus, and also higher pH in the water. Ozonation thus offers multiple benefits through its potential to degrade influenza antivirals, hence decrease the risk of environmental resistance development, in addition to degrading other pharmaceuticals and resistant microorganisms. PMID:26746418

  18. SHADOZ (Southern Hemisphere ADditional Ozonesondes}: What Have We Learned About Tropical Tropospheric Ozone from the First Three Years (1998-2000) Data

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    The first climatological overview of total, stratospheric and tropospheric ozone in the southern hemisphere tropical and subtropics is based on ozone sounding data from 10 sites comprising the Southern Hemisphere Additional OZonesondes (SHADOZ) network. The period covered is 1998-2000. Observations were made over: Ascension Island; Nairobi, Kenya; Irene, South Africa; Reunion Island; Watukosek, Java; Fiji; Tahiti; American Samoa; San Cristobal, Galapagos; Natal, Brazil. Campaign data were collected on an Trans-Atlantic oceanographic cruise and during SAFARI-2000 in Zambia. The ozone data, with simultaneous temperature profiles to approximately 7 hPa and relative humidity to approximately 200 hPa, reside at: . SHADOZ ozone time-series and profiles give a perspective on tropical total, stratospheric and tropospheric ozone in 1998-2000. Prominent features are highly variable tropospheric ozone, a zonal wave-one pattern in total (and tropospheric) column ozone, and signatures of the Quasi-Biennial Oscillation (QBO) in stratospheric ozone. Total, stratospheric and tropospheric column ozone amounts peak between August and November and are lowest between March and May. Tropospheric ozone variability over the Indian and Pacific Ocean displays influences of the Indian Ocean Dipole, and convective mixing. Pollution transport from Africa, South American and the Maritime Continent is a seasonal feature. Tropospheric ozone seasonality over the Atlantic Basin shows effects of regional subsidence and recirculation as well as biomass burning. Dynamical and chemical influences appear to be of comparable magnitude though model studies are needed to quantify this.

  19. SHADOZ (Southern Hemisphere ADditional Ozonesondes): What Have We Learned About Tropical Tropospheric Ozone from the First Three Years' (1998-2000) Data?

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Bhartia, Pawan (Technical Monitor)

    2002-01-01

    The first climatological overview of total, stratospheric and tropospheric ozone in the southern hemisphere tropical and subtropics is based on ozone sounding data from 10 sites comprising the Southern Hemisphere Additional OZonesondes (SHADOZ) network. The period covered is 1998-2000. Observations were made over: Ascension Island; Nairobi, Kenya; Irene, South Africa; RCunion Island; Watukosek, Java; Fiji; Tahiti; American Samoa; San Cristobal, Galapagos; Natal, Brazil. Campaign data were collected on a trans-Atlantic oceanographic cruise and during SAFARI-2000 in Zambia. The ozone data, with simultaneous temperature profiles to approx. 7 hPa and relative humidity to approx. 200 hPa, reside at: . SHADOZ ozone time-series and profiles give a perspective on tropical total, stratospheric and tropospheric ozone in 1998-2000. Prominent features are highly variable tropospheric ozone, a zonal wave-one pattern in total (and tropospheric) column ozone, and signatures of the Quasi-Biennial Oscillation (QBO) in stratospheric ozone. Total, stratospheric and tropospheric column ozone amounts peak between August and November and are lowest between March and May. Tropospheric ozone variability over the Indian and Pacific Ocean displays influences of the Indian Ocean Dipole, and convective mixing. Pollution transport from Africa, South American and the Maritime Continent is a seasonal feature. Tropospheric ozone seasonality over the Atlantic Basin shows effects of regional subsidence and recirculation as well as biomass burning. Dynamical and chemical influences appear to be of comparable magnitude though model studies are needed to quantify this.

  20. Identification and quantification of ozonation products of anthracene and phenanthrene adsorbed on silica particles

    NASA Astrophysics Data System (ADS)

    Perraudin, Emilie; Budzinski, Hélène; Villenave, Eric

    Primary products of the reactions of gas-phase ozone with anthracene and phenanthrene adsorbed on silica model particles have been investigated. Silica was selected as proxy for mineral atmospheric particles. The particles, coated with anthracene or phenanthrene and placed on a filter, were exposed in a reaction cell to a gaseous ozone flow. Ozone concentration was constant ((6.0±0.6)×10 13 molecule cm -3) during the experiments. Anthracene, phenanthrene and their ozonation products were then extracted by focused microwave-assisted extraction or fluid pressurized extraction and analyzed by gas chromatography coupled to mass spectrometry. Anthraquinone and anthrone on the one hand, and 1,1'-biphenyl-2,2'-dicarboxaldehyde on the other hand were identified as the products of anthracene and phenanthrene, respectively and quantified versus time of ozone exposure. This kinetical approach allowed to show that anthraquinone, anthrone and 1,1'-biphenyl-2,2'-dicarboxaldehyde are the primary products of the studied reactions, and to determine their formation yields (respectively, 0.42±0.04, 0.056±0.005 and 1.0±0.4).

  1. The 1998-2000 SHADOZ (Southern Hemisphere ADditional OZonesondes) Tropical Ozone Climatology: Ozonesonde Precision, Accuracy and Station-to-Station Variability

    NASA Technical Reports Server (NTRS)

    Witte, J. C.; Thompson, Anne M.; McPeters, R. D.; Oltmans, S. J.; Schmidlin, F. J.; Bhartia, P. K. (Technical Monitor)

    2001-01-01

    As part of the SAFARI-2000 campaign, additional launches of ozonesondes were made at Irene, South Africa and at Lusaka, Zambia. These represent campaign augmentations to the SHADOZ database described in this paper. This network of 10 southern hemisphere tropical and subtropical stations, designated the Southern Hemisphere ADditional OZonesondes (SHADOZ) project and established from operational sites, provided over 1000 profiles from ozonesondes and radiosondes during the period 1998-2000. (Since that time, two more stations, one in southern Africa, have joined SHADOZ). Archived data are available at: http://code9l6.gsfc.nasa.gov/Data-services/shadoz>. Uncertainties and accuracies within the SHADOZ ozone data set are evaluated by analyzing: (1) imprecisions in stratospheric ozone profiles and in methods of extrapolating ozone above balloon burst; (2) comparisons of column-integrated total ozone from sondes with total ozone from the Earth-Probe/TOMS (Total Ozone Mapping Spectrometer) satellite and ground-based instruments; (3) possible biases from station-to-station due to variations in ozonesonde characteristics. The key results are: (1) Ozonesonde precision is 5%; (2) Integrated total ozone column amounts from the sondes are in good agreement (2-10%) with independent measurements from ground-based instruments at five SHADOZ sites and with overpass measurements from the TOMS satellite (version 7 data). (3) Systematic variations in TOMS-sonde offsets and in groundbased-sonde offsets from station to station reflect biases in sonde technique as well as in satellite retrieval. Discrepancies are present in both stratospheric and tropospheric ozone. (4) There is evidence for a zonal wave-one pattern in total and tropospheric ozone, but not in stratospheric ozone.

  2. Spectroscopic study of degradation products of ciprofloxacin, norfloxacin and lomefloxacin formed in ozonated wastewater.

    PubMed

    Liu, Chen; Nanaboina, Venkateswarlu; Korshin, Gregory V; Jiang, Wenju

    2012-10-15

    This study addressed the formation and properties of degradation products of ciprofloxacin, norfloxacin and lomefloxacin formed during ozonation of secondary wastewater effluent containing these fluoroquinolone antibiotics. The generation of the degradation products was interpreted in the context of transformations of effluent organic matter (EfOM) tracked via absorbance measurements. The structures of 20 degradation products were elucidated for ciprofloxacin and norfloxacin, respectively. 27 degradation products were identified for lomefloxacin. The prevalent oxidation pathways were suggested based on the structures of the identified products formed in the absence and presence of the hydroxyl radical scavenger t-butanol. These pathways were largely similar for all studied fluoroquinolones and involved attacks on the piperazine ring and the quinolone structure. The quinolone ring remained intact in the presence of t-butanol thus indicating that this functional group could only be oxidized by OH radicals while the piperazine ring was readily oxidized by molecular ozone. The cleavage of the quinolone moiety that resulted in several identified degradation products occurred via the attack by hydroxyl radicals on the carbon-carbon double bond adjacent to the carboxylic acid group. Lomefloxacin had more diverse oxidation products due to the presence of a methyl group on its piperazinyl ring. The concentrations of the identified degradation products behaved non-monotonically as a function of ozone dose or treatment time, yet exhibited interpretable correlations versus changes of EfOM absorbance. Examination of these correlations allowed developing a novel approach for elucidating the transformations of fluoroquinolone antibiotics during ozonation. PMID:22863026

  3. Remediation of residues on stored product surfaces using ozone-based fumgiations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ozone fumigation, alone and in combination with other gases, was explored as a means for degrading “undesirable” organic residues on stored products. Organic residues sorbed onto model abiotic glass surfaces or onto stored products were fumigated separately in a flow-through chamber at 150 - 900 ± 1...

  4. Production of Ethylene Following Soil Biochar Additions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Overall, the initial hypotheses behind biochar’s impact on the soil microbial and plant systems have principally been focused on the interaction of the biochar with the soil structure, providing additional microbial habitat, improving water retention and infiltration, improving nutrient availability...

  5. Exploring the roles of temperature and NOx on ozone production in the Sacramento urban plume

    NASA Astrophysics Data System (ADS)

    Lafranchi, B. W.; Cohen, R. C.

    2009-12-01

    We investigate the role of temperature and NOx (NOx = NO+NO2) on ozone (O3) production in the Sacramento urban plume over a stretch of seven years (2001-2007) using data collected at UC Blodgett Forest Research Station (a forested site in the Sierra Nevadas about 80 km downwind of Sacramento, CA) and at a series of California Air Resources Board (CARB) sites along the Sacramento-Blodgett transect. The consistent daytime wind patterns between the Central Valley of California and the foothills of the Sierra Nevada mountains permits the assumption of plume transport from downtown Sacramento, over the CARB monitoring sites in the eastern suburbs, and past the Blodgett Forest research site. While NOx emissions are limited primarily to the urban and suburban regions of the transect, biogenic volatile organic compound (VOC) emissions are significant throughout the transect, thus there is a fast transition from VOC-limited to NOx-limited as the plume travels away from the urban center, and we have the opportunity to analyze the differences in ozone production across these two chemical regimes. For this analysis, the Sacramento-Blodgett transect is separated into three segments: urban, suburban, and rural, defined by the locations of selected monitoring sites. Ozone concentrations across each segment are controlled by chemical production (Pchem) and loss (Lchem), deposition to surfaces (Ldep), and mixing with background air (Lmix). At an assumed deposition rate, mixing rate, and background O3 concentration, the net chemical flux of ozone (Pchem - Lchem) can be inferred from differences in ozone concentrations between adjacent monitoring sites. We show that ozone production rates, in general, increase with temperature. We also show that decreases in NOx emissions over the period from 2001-2007 have been effective at reducing ozone production at all points along the transect, but only on days where temperatures are highest. At low temperatures, this decrease is less apparent

  6. Growth of continental-scale metro-agro-plexes, regional ozone pollution, and world food production

    SciTech Connect

    Chameides, W.L.; Kasibhatla, P.S. ); Yienger, J.; Levy, H. II )

    1994-04-01

    Three regions of the northern mid-latitudes, the continental-scale metro-agro-plexes, presently dominate global industrial and agricultural productivity. Although these regions cover only 23 percent of the Earth's continents, they account for most of the world's commercial energy consumption, fertilizer use, food-crop production, and food exports. They also account for more than half of the world's atmospheric nitrogen oxide (NO[sub x]) emissions and, as a result, are prone to ground-level ozone (O[sub 3]) pollution during the summer months. On the basis of a global simulation of atmospheric reactive nitrogen compounds, it is estimated that about 10 to 35 percent of the world's grain production may occur in parts of these regions where ozone pollution may reduce crop yields. Exposure to yield-reducing ozone pollution may triple by 2025 if rising anthropogenic NO[sub x] emissions are not abated.

  7. Growth of Continental-Scale Metro-Agro-Plexes, Regional Ozone Pollution, and World Food Production

    NASA Astrophysics Data System (ADS)

    Chameides, W. L.; Kasibhatla, P. S.; Yienger, J.; Levy, H., II

    1994-04-01

    Three regions of the northern mid-latitudes, the continental-scale metro-agro-plexes, presently dominate global industrial and agricultural productivity. Although these regions cover only 23 percent of the Earth's continents, they account for most of the world's commercial energy consumption, fertilizer use, food-crop production, and food exports. They also account for more than half of the world's atmospheric nitrogen oxide (NO_x) emissions and, as a result, are prone to ground-level ozone (O_3) pollution during the summer months. On the basis of a global simulation of atmospheric reactive nitrogen compounds, it is estimated that about 10 to 35 percent of the world's grain production may occur in parts of these regions where ozone pollution may reduce crop yields. Exposure to yield-reducing ozone pollution may triple by 2025 if rising anthropogenic NO_x emissions are not abated.

  8. The 1998-2000 SHADOZ (Southern Hemisphere ADditional Ozonesondes) Tropical Ozone Climatology: Comparison with TOMS and Ground-Based Measurements

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Witte, Jacquelyn; McPeters, Richard D.; Oltmans, Samuel J.; Schmidlin, Francis J.; Logan, Jennifer A.; Fujiwara, Masatormo; Kirchhoff, Volker W. J. H.; Posny, Francoise; Coetzee, Gerhard J. R.; Bhartia, P. K. (Technical Monitor)

    2001-01-01

    A network of 10 southern hemisphere tropical and Subtropical stations, designated the Southern Hemisphere ADditional OZonesondes, (SHADOZ) project and established from operational sites, provided over 1000 ozone profiles during the period 1998-2000. Balloon-borne electrochemical concentration cell (ECC) ozonesondes, combined with standard radiosondes for pressure, temperature and relative humidity measurements, collected profiles in the troposphere and lower- to mid-stratosphere at: Ascension Island; Nairobi, Kenya; Irene, South Africa: Reunion Island, Watukosek Java; Fiji; Tahiti; American Samoa; San Cristobal, Galapagos; Natal, Brazil.

  9. Turbulent transport and production/destruction of ozone in a boundary layer over complex terrain

    NASA Technical Reports Server (NTRS)

    Greenhut, Gary K.; Jochum, Anne M.; Neininger, Bruno

    1994-01-01

    The first Intensive Observation Period (IOP) of the Swiss air pollution experiment POLLUMET took place in 1990 in the Aare River Valley between Bern and Zurich. During the IOP, fast response measurements of meteorological variables and ozone concentration were made within the boundary layer aboard a motorglider. In addition, mean values of meteorological variables and the concentrations of ozone and other trace species were measured using other aircraft, pilot balloons, tethersondes, and ground stations. Turbulent flux profiles of latent and sensible heat and ozone are calculated from the fast response data. Terms in the ozone mean concentration budget (time rate of change of mean concentration, horizontal advection, and flux divergence) are calculated for stationary time periods both before and after the passage of a cold front. The source/sink term is calculated as a residual in the budget, and its sign and magnitude are related to the measured concentrations of reactive trace species within the boundary layer. Relationships between concentration ratios of trace species and ozone concentration are determined in order to understand the influence of complex terrain on the processes that produce and destroy ozone.

  10. The Influence of Pyrogenic, Biogenic and Anthropogenic Emissions on Ozone Production Downwind from Boreal Forest Fires

    NASA Astrophysics Data System (ADS)

    Finch, Douglas; Palmer, Paul

    2016-04-01

    Boreal forest fires emit pollutants that can have a strong influence on downwind surface ozone concentrations, with potential implications for exceeding air quality regulations. The influence of the mixing of pyrogenic, biogenic and anthropogenic emissions on ozone is not well understood. Using the nested 0.5° latitude x 0.667° longitude GEOS-Chem chemical transport model we track biomass burning plumes in North America. We identify the changes in key chemical reactions within these plumes as well as the sensitivity of ozone to the different emission sources. We illustrate the importance of this method using a case study of a multi-day forest fire during the BORTAS aircraft campaign over eastern Canada during summer 2011. We focus on emissions from the fire on the 17th of July and follow the plume for eight days. After the initial 24 hours of pyrogenic emissions the main source of VOCs is biogenic with increasing emissions from anthropogenic sources including outflow from Quebec City and Newfoundland. Using a Lagrangian framework, we show that the ozone production efficiency (OPE) of this plume decreases steadily as it moves away from the fire but increases rapidly as the plume reaches the east coast of Canada. Using a Eulerian framework we show that ozone mixing ratios of a east coast receptor region increase by approximately 15% even though the ozone tendency of the regional air mass is negative, which we find is due to the arrival of ozone precursors in the plume. We also consider the contribution of anthropogenic outflow over Nova Scotia that originates from the eastern seaboard of the United States to the local chemistry. Using these sensitivity model runs we generate a chemical reaction narrative for the plume trajectory that helps to understand the attribution of observed ozone variations.

  11. Simulation of Halocarbon Production and Emissions and Effects on Ozone Depletion

    PubMed

    Holmes; Ellis

    1997-09-01

    / This paper describes an integrated model that simulates future halocarbon production/emissions and potential ozone depletion. Applications and historical production levels for various halocarbons are discussed first. A framework is then presented for modeling future halocarbon impacts incorporating differences in underlying demands, applications, regulatory mandates, and environmental characteristics. The model is used to simulate the potential impacts of several prominent issues relating to halocarbon production, regulation, and environmental interactions, notably: changes in agricultural methyl bromide use, increases in effectiveness of bromine for ozone depletion, modifications to the elimination schedule for HCFCs, short-term expansion of CFC demand in low use compliance countries, and delays in Russian Federation compliance. Individually, each issue does not unequivocally represent a significant likely increase in long-term atmospheric halogen loading and stratospheric ozone depletion. In combination, however, these impacts could increase peak halogen concentrations and long-term integral halogen loading, resulting in higher levels of stratospheric ozone depletion and longer exposure to increased levels of UV radiation.KEY WORDS: Halocarbons; Ozone depletion; Montreal Protocol; Integrated assessment PMID:9236283

  12. An Observational Based Assessment of In-situ Photochemical Ozone Productivity in the European Boundary Layer

    NASA Astrophysics Data System (ADS)

    Rickard, A. R.; Monks, P. S.; Jonson, J. E.

    2003-04-01

    Empirical observational-based indicator relationships have been used over the past decade in order to investigate ozone production sensitivities to different NO_x/VOC levels. If such relationships can be proven to show marked and consistently different values under different NO_x- and VOC-limited regimes over a broad variety of conditions and geographical locations, then O_3-NO_x-VOC sensitivities and ozone production trends can be determined relatively quickly and simply from measurements rather than from complex models. Such correlations would also provide invaluable measurement data to test the accuracy of model chemistry sensitivities. The tracer indicator relationships O_3/NO_z, H_2O_2/HCHO, H_2O_2/NO_z and O_3/2H_2O_2+NO_z have principally been investigated using data from the Eastern Atlantic Summer/Spring Experiments (EASE 96 and 97 respectively), which took place at Mace Head, on the west coast of Ireland. In order to study the chemistry occurring in the different air masses arriving at Mace Head, minute-averaged data were divided up into five wind sectors according to wind direction and speed. The measurements were additionally segregated using a back trajectory classification method in order to identify the pollution regimes encountered. Some of the calculated results have been compared and contrasted to those calculated from data measured under southern hemispheric "baseline" conditions, collected during the Southern Ocean Atmospheric Photochemistry EXperiment (SOAPEX 2), which took place at Cape Grim on the Tasmanian coast in the Austral summer of 1999 and from the Terrestrial Initiative in Global Environmental Research program (TIGER 95) which took place at Weybourne on the North Norfolk coast in summer 1995. Finally, the above observed indicator ratios, calculated from hourly values for EASE 97, have been compared to those calculated from model data from the EMEP-E regional model (DNMI) for May 1997.

  13. By-products formation during degradation of isoproturon in aqueous solution. I: Ozonation.

    PubMed

    Mascolo, G; Lopez, A; James, H; Fielding, M

    2001-05-01

    The degradation of the herbicide isoproturon during its ozonation in aqueous solution has been investigated with the aim of identifying intermediate as well as final by-products formed. At ambient temperature, phosphate-buffered (pH = 7) isoproturon aqueous solutions (10, 10(-1) and 10(-3) mg/l) were ozonated in a semi-batch reactor, under a continuous flow of ozonated air whose ozone concentration was 9 and 0.9 mg O3/lair for the highest and the two lower herbicide concentrations respectively. Measured steady-state ozone concentrations during the two sets of experiments (i.e. the highest and the lower isoproturon concentration) were 1.9 and 0.7 mg O3/l. Under all of the above conditions, isoproturon was always completely removed in a period ranging between 5 and 15 min, essentially by reacting with molecular ozone. High-performance liquid chromatography-mass spectrometry (HPLC-MS) analyses indicate that primary degradation by-products are formed either by introducing OH groups in the aromatic ring and/or in the side-chain substituents, or by breaking down the isopropyl alkyl chain. The results also show that these primary intermediates are successively degraded yielding low molecular weight compounds such as aldehydes, simple organic acids and alpha-oxo-acids, which have been identified by gas chromatography-electron capture detection (GC-ECD), ion chromatography (IC) and GC-MS, respectively. On the basis of the analytical results, a pathway for the degradation of isoproturon by ozone has been proposed. PMID:11329671

  14. INFLUENCE OF LIGHT ON OZONE-INDUCED 1-AMINOCYCLOPROPANE-1-CARBOXYLIC ACID AND ETHYLENE PRODUCTION FROM INTACT PLANTS

    EPA Science Inventory

    The influence of light on ozone-induced ethylene production from intact soybean (Glycine max L. Merr. cv. Dare) and tomato (Lycopersicon esculentum Mill. cv. Roma) plants was investigated. Ozone-induced stress ethylene production was 2.6-fold greater from dark-than light-incubate...

  15. The Characteristics Improvement of Ozone Water Production by Multi-layer Electrodes at Water Electrolysis Cell by Solid Polymer Electrolyte

    NASA Astrophysics Data System (ADS)

    Ohba, Takahiro; Kusunoki, Hironobu; Sunakawa, Daisuke; Araki, Takuto; Onda, Kazuo

    Ozone is recently used for many purposes as an environmental friendly oxidant, so the ozone production device with high ozone concentration and low production energy is desired. One of the candidates for such device is the ozone water production by water electrolysis cell using the solid polymer electrolyte with PbO2 anode catalyst, which has merits to be compact and to produce high-concentration ozone water directly by the deionized water electrolysis. In this study, we have tested ozone water production by changing electrodes and electrolytes constitution in order to improve the ozone production performance. Tested two electrolytes are Nafion117 and a membrane-electrode assembly (MEA) with Pt catalyst on cathode side of Nafion117. Tested two electrodes are mono-layer of Ti expanded metal and four different mesh layers of Ti expanded metal. Ozone water production tests are performed under long-term operations changing temperature and flow rate to optimize experimental conditions. The voltage-current characteristic for electrolysis cell have been improved significantly, when the electrode is four layers of Ti metal and the electrolyte is the MEA with Pt catalyst. The stable ozone water concentration has been obtained by operating the cell for about 8 hours. The optimum temperature and water flow rate for ozone water production are 25˜30° and 33L/h, respectively. Furthermore, the optimum overpotential was measured by a reference electrode at the cathode-side MEA, and the anode catalyst suitable for ozone water production was identified to be βPbO2 by the X ray diffraction pattern.

  16. Ozone production using dielectric barrier discharge in oxygen and carbon dioxide

    NASA Astrophysics Data System (ADS)

    Pontiga, Francisco; Abidat, Roukia; Moreno, Helena; Agustín, Fernández-Rueda; Rebiaï, Saida

    2015-09-01

    The generation of ozone in oxygen and carbon dioxide using a planar dielectric barrier discharge (DBD) has been experimentally investigated. The DBD reactor was operated at moderate voltages (4.2 to 5.6 kV) and frequencies (50 to 500 Hz) and the gas flow rate was varied in the range 50 to 200 cm3/min. The averaged consumed power (<1 W) was evaluated using a monitor capacitor of known capacitance (1 μF). The effluent gas from the DBD reactor was diverted to a gas cell situated inside the sample compartment of a UV spectrophotometer. Therefore, ozone concentration was determined from the measurement of absorbance using Beer-Lambert law. The results have shown that ozone concentration in oxygen grows very linearly with the input power. In contrast, the production of ozone in carbon dioxide is less regular, which may be due to the deposition of a thin layer over the stainless steel electrode during the application of the electrical discharge. Moreover, the rate of ozone production with the injected energy density was found to be 500 times weaker in carbon dioxide than in pure oxygen. This work was supported by the Spanish Government Agency ``Ministerio de Ciencia e Innovación'' under Contract No. FIS2011-25161.

  17. Products from the reaction of monoterpenes with ozone and their distribution between the gas- and particle-phase

    NASA Astrophysics Data System (ADS)

    Winterhalter, R.; Römpp, A.; Kavouras, I. G.; Moortgat, G. K.

    2003-04-01

    The monoterpene-ozone reaction is an important source of tropospheric aerosols, yet the formation mechanism and physico-chemical properties of the organic aerosol particles are not well understood. In this paper a detailed product study of the gas-phase ozonolysis of various monoterpenes (alpha-pinene, beta-pinene, sabinene, limonene, and 3-carene) is presented, with special focus on the distribution of the products between the gas- and aerosol phase. The reactions were performed in a 570 l glass reactor at 730 Torr and room temperature in synthetic air in the presence and absence of cyclohexane as OH-radical scavenger. The reaction was monitored by FTIR-spectroscopy (ozone, monoterpenes and gas-phase products) and by a Scanning Mobility Particle Sizer (Size distribution, aerosol volume and number concentration). The separation of gas-phase and particulate products was achieved by a combination of gas-phase denuder and filter sampling. Particles were collected with quartz fiber filter coated with 1M NaOH and additionally with teflon filters, while gaseous products were sampled with a diffusion denuder coated with 1M NaOH. The reaction products have been extracted with water, and the extracts have been analysed by LC-MS-MS-TOF using ESI (-) and APCI (+) ionisation. Furthermore the samples have been also analysed by GC-MS after derivatization of the organic acids. The products and their gas-particle partitioning will be presented, and the possible reaction mechanisms will be discussed.

  18. Comparison of NASA OMI and MLS Ozone Products with US Forest Service Ground-based Ozone Monitoring Data for US Forest Service Air Quality / Forest Management Decision Support

    NASA Astrophysics Data System (ADS)

    Barrett, S.; Brooks, A.; Moussa, Y.; Spencer, T.; Thompson, J.

    2013-12-01

    Tropospheric ozone, formed when nitrogen oxides (NOx) and volatile organic compounds (VOCs) react with sunlight, is a significant threat to the health of US National Forests. Approximately one third of ozone is absorbed by plants during the uptake of carbon dioxide. This increases the vegetation's susceptibility to drought, beetle infestation, and wildfire. Currently the US Forest Service has ground monitoring stations sparsely located across the country. This project looks specifically at the area surrounding several Class I Wilderness Areas in the Appalachian region. These areas are the highest priority for protection from air pollutants. The Forest Service must interpolate ozone concentrations for areas between these monitoring stations. Class I Wilderness Areas are designated by the Forest Service and are defined as a total 5000 acres or greater when the Clean Air Act was passed in 1977. This Act mandated that the EPA create national ambient air quality standards (NAAQS) for six major air pollutants including ground-level ozone. This project assessed the feasibility of incorporating NASA ozone data into Forest Service ozone monitoring in an effort to enhance the accuracy and precision of ozone exposure measurements in Class I Wilderness Areas and other federally managed lands in order to aid in complying with the Clean Air Act of 1977. This was accomplished by establishing a method of comparison between a preliminary data product produced at the Goddard Space Flight Center that uses OMI/MLS data to derive global tropospheric ozone measurements and Forest Service ozone monitoring station measurements. Once a methodology for comparison was established, statistical comparisons of these data were performed to assess the quantitative differences.

  19. 21 CFR 607.31 - Additional blood product listing information.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Additional blood product listing information. 607... BLOOD AND BLOOD PRODUCTS Procedures for Domestic Blood Product Establishments § 607.31 Additional blood... following information by letter or by Federal Register notice: (1) For a particular blood product so...

  20. 21 CFR 607.31 - Additional blood product listing information.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 7 2012-04-01 2012-04-01 false Additional blood product listing information. 607... BLOOD AND BLOOD PRODUCTS Procedures for Domestic Blood Product Establishments § 607.31 Additional blood... following information by letter or by Federal Register notice: (1) For a particular blood product so...

  1. 21 CFR 607.31 - Additional blood product listing information.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 7 2014-04-01 2014-04-01 false Additional blood product listing information. 607... BLOOD AND BLOOD PRODUCTS Procedures for Domestic Blood Product Establishments § 607.31 Additional blood... following information by letter or by Federal Register notice: (1) For a particular blood product so...

  2. 21 CFR 607.31 - Additional blood product listing information.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Additional blood product listing information. 607... BLOOD AND BLOOD PRODUCTS Procedures for Domestic Blood Product Establishments § 607.31 Additional blood... following information by letter or by Federal Register notice: (1) For a particular blood product so...

  3. 21 CFR 607.31 - Additional blood product listing information.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Additional blood product listing information. 607... BLOOD AND BLOOD PRODUCTS Procedures for Domestic Blood Product Establishments § 607.31 Additional blood... following information by letter or by Federal Register notice: (1) For a particular blood product so...

  4. Atmospheric oxidation chemistry and ozone production: Results from SHARP 2009 in Houston, Texas

    NASA Astrophysics Data System (ADS)

    Ren, Xinrong; Duin, Diana; Cazorla, Maria; Chen, Shuang; Mao, Jingqiu; Zhang, Li; Brune, William H.; Flynn, James H.; Grossberg, Nicole; Lefer, Barry L.; Rappenglück, Bernhard; Wong, Kam W.; Tsai, Catalina; Stutz, Jochen; Dibb, Jack E.; Thomas Jobson, B.; Luke, Winston T.; Kelley, Paul

    2013-06-01

    Ozone (O3) and secondary fine particles come from the atmospheric oxidation chemistry that involves the hydroxyl radical (OH) and hydroperoxyl radical (HO2), which are together called HOx. Radical precursors such as nitrous acid (HONO) and formaldehyde (HCHO) significantly affect the HOx budget in urban environments. These chemical processes connect surface anthropogenic and natural emissions to local and regional air pollution. Using the data collected during the Study of Houston Atmospheric Radical Precursors (SHARP) in spring 2009, we examine atmospheric oxidation chemistry and O3 production in this polluted urban environment. A numerical box model with five different chemical mechanisms was used to simulate the oxidation processes and thus OH and HO2 in this study. In general, the model reproduced the measured OH and HO2 with all five chemical mechanisms producing similar levels of OH and HO2, although midday OH was overpredicted and nighttime OH and HO2 were underpredicted. The calculated HOx production was dominated by HONO photolysis in the early morning and by the photolysis of O3 and oxygenated volatile organic compounds (OVOCs) in the midday. On average, the daily HOx production rate was 24.6 ppbv d-1, of which 30% was from O3 photolysis, 22% from HONO photolysis, 15% from the photolysis of OVOCs (other than HCHO), 14% from HCHO photolysis, and 13% from O3 reactions with alkenes. The O3 production was sensitive to volatile organic compounds (VOCs) in the early morning but was sensitive to NOx for most of afternoon. This is similar to the behavior observed in two previous summertime studies in Houston: the Texas Air Quality Study in 2000 (TexAQS 2000) and the TexAQS II Radical and Aerosol Measurement Project in 2006 (TRAMP 2006). Ozone production in SHARP exhibits a longer NOx-sensitive period than TexAQS 2000 and TRAMP 2006, indicating that NOx control may be an efficient approach for the O3 control in springtime for Houston. Results from this study

  5. EVALUATION OF OZONATION BY-PRODUCTS FROM TWO CALIFORNIA SURFACE WATERS

    EPA Science Inventory

    Ozonation by-products were analyzed for two surface water sources in Southern California-Los Angeles Aqueduct Water (LAWW) and State Project Water (SPW). Included are data obtained when LAAW was being treated at the Los Angeles Aqueduct Filtration Plant and similar data obtained...

  6. THE OZONE REACTION WITH BUTADIENE: FORMATION OF TOXIC PRODUCTS. (R826236)

    EPA Science Inventory

    Abstract

    The formation yields of acrolein, 1,2-epoxy-3-butene and OH radicals have been measured from reaction of ozone with 1,3-butadiene at room temperature and atmosphere pressure. 1,3,5-Trimethyl benzene was added to scavenge OH radicals in measurements of product ...

  7. FORMATION AND STABILITY OF OZONATION BY-PRODUCTS IN DRINKING WATER

    EPA Science Inventory

    A project is proposed that will study a wide-range of by-products resulting from the combined use of ozone (as a pre-oxidation treatment) with terminal disinfectants chlorine and chloramine. This study will first investigate new methodologies for targeting as yet unidentified by-...

  8. Toward Describing the Effects of Ozone Depletion on Marine Primary Productivity and Carbon Cycling

    NASA Technical Reports Server (NTRS)

    Cullen, John J.

    1995-01-01

    This project was aimed at improved predictions of the effects of UVB and ozone depletion on marine primary productivity and carbon flux. A principal objective was to incorporate a new analytical description of photosynthesis as a function of UV and photosynthetically available radiation (Cullen et. al., Science 258:646) into a general oceanographic model. We made significant progress: new insights into the kinetics of photoinhibition were used in the analysis of experiments on Antarctic phytoplankton to generate a general model of UV-induced photoinhibition under the influence of ozone depletion and vertical mixing. The way has been paved for general models on a global scale.

  9. Products and mechanisms of the reaction of gas phase ozone with organic colorants

    SciTech Connect

    Grosjean, D. ); Druzik, J.R. ); Sensharma, D.K. ); Whitmore, P.M.; DeMoor, C.P.; Cass, G.R. )

    1988-09-01

    Studies carried out in this laboratory have shown that many artists organic colorants fade substantially when exposed to ozone in the dark. These studies typically involved pigment exposure for 12 weeks to purified air containing 0.3-0.4 ppm of ozone at ambient temperature and humidity. These laboratory conditions are equivalent to about six years of exposure inside a typical air-conditioned building in Los Angeles, and the observed fading is therefore directly relevant to possible damage to works of arts in museum settings. Organic colorants that were most ozone-fugitive included natural colorants, such as curcumin and indigo, as well as modern synthetic colorants such as alizarin lakes and triphenylmethane dyes. Thus, these colorants were selected for further study with emphasis on the nature of the reaction products. Exposures were carried out on different substrates including watercolor paper, cellulose, silica gel, and Teflon. The experiments involved long-term exposure to low levels of ozone (e.g. {approximately} 0.3 ppm for 90 days) or shorter-term exposure to higher ozone concentrations (e.g. 10 ppm for 24 hours). Exposed and control samples, along with solvent and substrate blanks, were analyzed by mass spectrometry using a Kratos Scientific Instruments MS25 hexapole mass spectrometer operated in either methane chemical ionization (CI) or electron impact (EI) modes.

  10. Oestrogenicity assessment of s-triazines by-products during ozonation.

    PubMed

    Pereira, S V; Reis, T; Souza, B S; Dantas, R F; Azevedo, D A; Dezotti, M; Sans, C; Esplugas, S

    2015-01-01

    The triazines are a group of herbicides with a wide range of uses. Atrazine is, in fact, one of the most used agricultural pesticides in the world. The terbuthylazine is applied as a substitute of atrazine in some countries of Europe since 2004, when the European Union announced a ban of atrazine because of ubiquitous water contamination. In this study, both atrazine and terbuthylazine were degraded by the ozone process to estimate the efficiency on pesticide removal in water, the intermediates formed and their potential oestrogenic activity using the yeast oestrogen screen (YES) test. Both pesticides were rapidly eliminated from the medium during ozonation (applied ozone dose 0.083 and 0.02 mmol O3 L(-1), respectively). The results show that both compounds generated similar by-products from ozone degradation. Moreover, significant oestrogenic activity was detected for both atrazine and terbuthylazine intermediates, during the first minutes of ozonation. The YES assay used in this study proved to be a sensitive tool in assessing trace amounts of oestrogenic chemicals, which can represent critical issues influencing the experimental results in environmental applications. PMID:25491130

  11. Oxidation of cetirizine, fexofenadine and hydrochlorothiazide during ozonation: Kinetics and formation of transformation products.

    PubMed

    Borowska, Ewa; Bourgin, Marc; Hollender, Juliane; Kienle, Cornelia; McArdell, Christa S; von Gunten, Urs

    2016-05-01

    The efficiency of wastewater ozonation for the abatement of three nitrogen-containing pharmaceuticals, two antihistamine drugs, cetirizine (CTR) and fexofenadine (FXF), and the diuretic drug, hydrochlorothiazide (HCTZ), was investigated. Species-specific second-order rate constants for the reactions of the molecular, protonated (CTR, FXF) or deprotonated (HCTZ) forms of these compounds with ozone were determined. All three compounds are very reactive with ozone (apparent second order rate constants at pH 7: kO3,pH7 = 1.7·10(5) M(-1)s(-1), 8.5·10(4) M(-1)s(-1) and 9.0·10(3) M(-1)s(-1) for CTR, HCTZ and FXF, respectively). Transformation product (TP) structures were elucidated using liquid chromatography coupled with high-resolution tandem mass spectrometry, including isotope-labeled standards. For cetirizine and hydrochlorothiazide 8 TPs each and for fexofenadine 7 TPs were identified. The main TPs of cetirizine and fexofenadine are their respective N-oxides, whereas chlorothiazide forms to almost 100% from hydrochlorothiazide. In the bacteria bioluminescence assay the toxicity was slightly increased only during the ozonation of cetirizine at very high cetirizine concentrations. The main TPs detected in bench-scale experiments were also detected in full-scale ozonation of a municipal wastewater, for >90% elimination of the parent compounds. PMID:26971810

  12. 40 CFR Appendix H to Subpart A of... - Clean Air Act Amendments of 1990 Phaseout Schedule for Production of Ozone-Depleting Substances

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Phaseout Schedule for Production of Ozone-Depleting Substances H Appendix H to Subpart A of Part 82... STRATOSPHERIC OZONE Production and Consumption Controls Pt. 82, Subpt. A, App. H Appendix H to Subpart A of Part 82—Clean Air Act Amendments of 1990 Phaseout Schedule for Production of Ozone-Depleting...

  13. Markers of heterogeneous reaction products in α-pinene ozone secondary organic aerosol

    NASA Astrophysics Data System (ADS)

    Czoschke, Nadine M.; Jang, Myoseon

    A gas chromatograph iontrap mass spectrometer (GC-ITMS) was used to analyze the gas-and particle-phase products of α-pinene ozone oxidation in the presence of three different inorganic seed aerosols: sodium chloride, ammonium sulfate only, and ammonium sulfate with sulfuric acid. Products of α-pinene ozone oxidation common to the literature showed little difference in gas or particle-phase concentrations between seed types within the precision of the measurements even though significantly different aerosol yields were found between seed types. Small amounts of ring-opening products of four-membered cyclic oxygenates and markers of aldol condensation products were tentatively identified in the particle-phase for all seed types. These tentatively identified products are thought to be the result of acid-catalyzed heterogeneous reactions in the particle-phase or during sampling processes or analysis. The mechanisms for their formation are also proposed in this study.

  14. Intercontinental Transport of Tropical Ozone from Biomass Burning: Views from Satellite and SHADOZ (Southern Hemisphere Additional Ozonesondes)

    NASA Technical Reports Server (NTRS)

    Thompson, A. M.; Witte, J. C.; Chatfield, R. B.; Guam, H.

    2003-01-01

    There has been interest in the connection between tropical fires and ozone since about 1980. Photochemically reactive gases released by fires (e.g. NO, CO, volatile organic carbon) interact as they do in an urban environment to form ozone. Interacting with chemical sources, tropical meteorology plays a part in tropospheric ozone distributions in the tropics, through large-scale circulation, deep convection, and regional phenomena like the West African and Asian monsoons. An overview of observations, taken from satellite and from ozone soundings, illustrates regional influences and intercontinental- range ozone transport in the tropics. One of the most striking findings is evidence for impacts of Indian Ocean pollution on the south Atlantic ozone maximum referred to as the "ozone paradox" [Thompson et al., GRL, 2000; JGR, 2003; Chatfield et al., GRL, 20031.

  15. Release 2 data products from the Ozone Mapping and Profiler Suite (OMPS) Limb Profiler

    NASA Technical Reports Server (NTRS)

    Xu, Q. Philippe; Bhartia, Pawan K.; Jaross, Glen R.; Deland, Matthew T.; Larsen, Jack C.; Fleig, Albert; Kahn, Daniel; Zhu, Tong; Chen, Zhong; Gorkavyi, Nick; Warner, Jeremy; Linda, Mike; Chen, Hong; Kowitt, Mark; Haken, Michael; Hall, Peter

    2014-01-01

    The OMPS Limb Profiler (LP) was launched on board the NASA Suomi National Polar-orbiting Partnership (SNPP) satellite in October 2011. OMPS-LP is a limb-scattering hyperspectral sensor that provides ozone profiling capability at 1.5 km vertical resolution from cloud top to 60 km altitude. The use of three parallel slits allows global coverage in approximately four days. We have recently completed a full reprocessing of all LP data products, designated as Release 2, that improves the accuracy and quality of these products. Level 1 gridded radiance (L1G) changes include intra-orbit and seasonal correction of variations in wavelength registration, revised static and intra-orbit tangent height adjustments, and simplified pixel selection from multiple images. Ozone profile retrieval changes include removal of the explicit aerosol correction, exclusion of channels contaminated by stratospheric OH emission, a revised instrument noise characterization, improved synthetic solar spectrum, improved pressure and temperature ancillary data, and a revised ozone climatology. Release 2 data products also include aerosol extinction coefficient profiles derived with the prelaunch retrieval algorithm. Our evaluation of OMPS LP Release 2 data quality is good. Zonal average ozone profile comparisons with Aura MLS data typically show good agreement, within 5-10% over the altitude range 20-50 km between 60 deg S and 60 deg N. The aerosol profiles agree well with concurrent satellite measurements such as CALIPSO and OSIRIS, and clearly detect exceptional events such as volcanic eruptions and the Chelyabinsk bolide in February 2013.

  16. Simulation of halocarbon production and emissions and effects on ozone depletion

    SciTech Connect

    Holmes, K.J.; Ellis, H.

    1997-09-01

    This paper describes an integrated model that simulates future halocarbon production/emissions and potential ozone depletion. Applications and historical production levels for various halocarbons are discussed first. A framework is then presented for modeling future halocarbon impacts incorporating differences in underlying demands, applications, regulatory mandates, and environmental characteristics. The model is used to simulate the potential impacts of several prominent issues relating to halocarbon production, regulation, and environmental interactions, notably changes in agricultural methyl bromide use, increases in effectiveness of bromide for ozone depletion, modifications to the elimination schedule for HCFCs, short-term expansion of CFC demand in low use compliance countries, and delays in Russian Federation compliance. Individually, each issue does not unequivocally represent a significant likely increase in long-term atmospheric halogen loading and stratospheric ozone depletion. In combination, however, these impacts could increase peak halogen concentrations and long-term integral halogen loading, resulting in higher levels of stratospheric ozone depletion and longer exposure to increased levels of UV radiation.

  17. Indoor Secondary Pollutants from Household Product Emissions inthe Presence of Ozone: A Bench-Scale Chamber Study

    SciTech Connect

    Destaillats, Hugo; Lunden, Melissa M.; Singer, Brett C.; Coleman,Beverly K.; Hodgson, Alfred T.; Weschler, Charles J.; Nazaroff, William W.

    2005-10-01

    Ozone-driven chemistry is a major source of indoor secondary pollutants of health concern. This study investigates secondary air pollutants formed from reactions between constituents of household products and ozone. Gas-phase product emissions were introduced along with ozone at constant rates into a 198-L Teflon-lined reaction chamber. Gas-phase concentrations of reactive terpenoids and oxidation products were measured. Formaldehyde was a predominant oxidation byproduct for the three studied products, with yields under most conditions of 20-30% with respect to ozone consumed. Acetaldehyde, acetone, glycolaldehyde, formic acid and acetic acid were each also detected for two or three of the products. Immediately upon mixing of reactants, a scanning mobility particle sizer detected particle nucleation events that were followed by a significant degree of ultrafine particle growth. The production of secondary gaseous pollutants and particles depended primarily on the ozone level and was influenced by other parameters such as the air-exchange rate. Hydroxyl radical concentrations in the range 0.04-200 x 10{sup 5} molecules cm{sup -3} were measured. OH concentrations were observed to vary strongly with residual ozone level in the chamber, which was in the range 1-25 ppb, as is consistent with expectations from a simplified kinetic model. In a separate test, we exposed the dry residue of two products to ozone in the chamber and observed the formation of gas-phase and particle-phase secondary oxidation products.

  18. Total Ozone Mapping Spectrometer (TOMS) Level-3 Data Products User's Guide

    NASA Technical Reports Server (NTRS)

    McPeters, Richard D.; Bhartia, P. K.; Krueger, Arlin J.; Herman, Jay R.; Wellemeyer, Charles G.; Seftor, Colin J.; Byerly, William; Celarier, Edward A.

    2000-01-01

    Data from the TOMS series of instruments span the time period from November 1978, through the present with about a one and a-half year gap from January 1994 through July 1996. A set of four parameters derived from the TOMS measurements have been archived in the form of daily global maps or Level-3 data products. These products are total column ozone, effective surface reflectivity, aerosol index, and erythermal ultraviolet estimated at the Earth surface. A common fixed grid of I degree latitude by 1.25 degree longitude cells over the entire globe is provided daily for each parameter. These data are archived at the Goddard Space Flight Center Distributed Active Archive Center (DAAQ in Hierarchical Data Format (HDF). They are also available in a character format through the TOMS web site at http://toms.gsfc.nasa.gov. The derivations of the parameters, the mapping algorithm, and the data formats are described. The trend uncertainty for individual TOMS instruments is about 1% decade, but additional uncertainty exists in the combined data record due to uncertainty in the relative calibrations of the various TOMS.

  19. Effects of ozone on primary determinants of plant productivity. Final report, 15 May 1986-15 February 1988

    SciTech Connect

    Olszyk, D.M.; Heath, R.L.; Takemoto, B.K.

    1988-04-01

    This study evaluated the relationships among ozone exposure, gas exchange, chlorophyll fluorescence, and whole-plant productivity for Spinacea oleracea. Lactuca sativa, Zea mays, Cucumis pepo, and Raphanus sativus in a greenhouse with plants grown hydroponically (spinach) or in loose media (other species) to allow recovery of root systems. Spinach showed decreases in stomatal conductance and transpiration, with variable exposure producing greater effects than constant exposure. Net photosynthesis was affected by ozone less than were the gas-exchange parameters. Radish was the only species showing consistent ozone effects with reductions in both shoot and root dry weight. Gas exchange was not consistently correlated with productivity. Chlorophyll fluorescence measurements were stable and reproducible, but changes in fluorescence induced by low ozone levels were not easily observed. The study clearly showed that even though changes in gas exchange and plant productivity occur with ozone exposure, the relationships among them are difficult to detect.

  20. Interaction of ozone with wooden building products, treated wood samples and exotic wood species

    NASA Astrophysics Data System (ADS)

    Schripp, Tobias; Langer, Sarka; Salthammer, Tunga

    2012-07-01

    Wooden building products indoors are known to be able to affect the perceived air quality depending on their emission strength. The indoor application of modern ecological lacquer systems (eco-lacquers or 'green' lacquers) may be a much stronger source than the substrates itself. Especially with regard to the formation of ultrafine particles by gas-to-particle conversion in the presence of ozone or other reactive species the impact of the applied building products on the indoor air quality has to be addressed. The present study reports a two concentration step ozonation of OSB panels, painted beech boards, and a number of solid 'exotic' wood types in a 1 m³ emission test chamber. The emission of volatile organic compounds (VOC) was recorded as well as the formation of ultrafine particles in the range 7-300 nm. The products are characterized on the basis of their ozone deposition velocity; the obtained values of 0.008-0.381 cm s-1 are comparable with previously published data. Within the samples of the present study one eco-lacquer was the strongest source of VOC (total VOC ˜ 60 mg m-3) while the wooden building products (OSB) were of intermediate emission strength. The lowest emission was found for the solid (exotic) wood samples. The VOC release of the samples corresponded roughly to the particle formation potential. However, the strongest UFP formation was measured for one solid wood sample ('Garapa') which showed a strong surface reaction in the presence of ozone and formed a large number of particles <40 nm. Overall, the experiments demonstrated the necessity of real-life samples for the estimation of UFP indoor air pollution from the ozone chemistry of terpenes.

  1. Radical Chemistry and Ozone Production in the Houston Industrial Area

    NASA Astrophysics Data System (ADS)

    Sommariva, R.; Brown, S. S.; Roberts, J. M.; Parker, A. E.; Brookes, D. M.; Monks, P. S.; Osthoff, H. D.; Gilman, J. B.; Goldan, P. D.; Kuster, W. C.; Lerner, B. M.; Welsh-Bon, D.; Williams, E. J.; Fehsenfeld, F. C.; Ravishankara, A. R.; Trainer, M.

    2007-12-01

    Measurements of radicals (HO2+RO2, NO3) were taken on board of the NOAA ship R/V Brown during the Texas Air Quality Study/Gulf of Mexico Atmospheric Composition and Climate Study (TexAQS/GoMACCS) 2006 field campaign. HO2+RO2 was measured by Chemical Amplification and NO3 (with N2O5) was measured by Cavity Ring-Down Spectroscopy. The R/V Brown cruised for a month (August-September 2006) off the coast of Texas and inside Galveston Bay and Houston industrial and shipping area, sampling air masses coming from the highly industrialized region of Southern United States. The data collected during the cruise were analyzed using a zero-dimensional box-model based upon the Leeds Master Chemical Mechanism (MCM). The model was constrained to the measurements of long-lived species and physical parameters and used to calculate the concentrations of radicals (OH, HO2, RO2, NO3) during the cruise of the R/V Brown. The modelled concentrations of HO2+RO2 and NO3 were compared with the measurements. The model and the measurements were used to study ozone formation and photochemistry in one of the most polluted areas of the United States.

  2. Validation of three different scientific ozone products retrieved from IASI spectra using ozonesondes

    NASA Astrophysics Data System (ADS)

    Dufour, G.; Eremenko, M.; Griesfeller, A.; Barret, B.; Leflochmoën, E.; Clerbaux, C.; Hadji-Lazaro, J.; Coheur, P.-F.; Hurtmans, D.

    2011-08-01

    Three scientific ozone products from the Infrared Atmospheric Sounding Interferometer (IASI) aboard MetOp-A, retrieved in three different research teams (LA, LATMOS/ULB, LISA) with different retrieval schemes, are characterized and validated using ozonesondes measurements. The three products are mature enough to be used for detailed analyses of atmospheric chemistry and transport in the troposphere. The characteristics of the products are analyzed in terms of retrieval sensitivity, systematic and random errors, and ability to retrieve the natural variability of ozone and focus on different partial columns from the lower troposphere up to 30 km. The validation covers the midlatitudes and the tropics and the period from January to December 2008. The products present degrees of freedom (DOF) in the troposphere between 1 and 1.2 on average in the midlatitudes and between 1 and 1.4 in the tropics. The DOF are distributed differently on the vertical depending on the profiles and the season: summer leading to a better sensitivity to the lower troposphere, as expected. The error estimates range between 10 and 20 % from the lower tropospheric partial columns (0-6 km and 0-8 km for the midlatitudes and the tropics respectively) to the UTLS partial columns (8-16 km and 11-20 km for the midlatitudes and the tropics respectively) for all the products and are about 5 % in the stratosphere (16-30 km) and for the column up to 30 km. The main feature that arises from the comparison with the ozonesondes is a systematic overestimation of ozone in the UTLS (between 10 and 25 %) by the three products in the midlatitudes and the tropics, attributed to the moderate vertical resolution of IASI and possibly to spectroscopic inconsistencies. The ability of the products to reproduce natural variability of tropospheric ozone is fairly good and depends on the considered season and region.

  3. Degradation of reactive dyes in wastewater from the textile industry by ozone: analysis of the products by accurate masses.

    PubMed

    Constapel, Marc; Schellenträger, Marc; Marzinkowski, Joachim Michael; Gäb, Siegmar

    2009-02-01

    The present work describes the use of ozone to degrade selected reactive dyes from the textile industry and the analysis of the resulting complex mixture by liquid chromatography/mass spectrometry (LC-MS). To allow certain identification of the substances detected in the wastewater, the original dyes were also investigated either separately or in a synthetic mixture of three dyes (trichromie). Since the reactive dyes are hydrolyzed during the dyeing process, procedures for the hydrolysis were worked out first for the individual dyes. The ozonated solutions were concentrated by solid-phase extraction, which separated very polar or ionic substances from moderately polar degradation products. The latter, which are the primary degradation products, were investigated by liquid chromatography/mass spectrometry with a tandem quadrupole time-of-flight mass analyzer. Accurate masses, which in most cases could be determined with a deviation of addition, a diode-array detector was placed before the mass analyzer to provide UV-vis spectra of the products in the same run. With retention times, mass spectra, accurate masses, UV-vis spectra and, of course, knowledge of the structures of the original dyes, plausible structures could be proposed for most of the components of the moderately polar fraction. These structures were confirmed by 1H NMR in cases where it was practical to isolate the degradation products by preparative HPLC. PMID:19110293

  4. Ozonation of ranitidine: Effect of experimental parameters and identification of transformation products.

    PubMed

    Christophoridis, Christophoros; Nika, Maria-Christina; Aalizadeh, Reza; Thomaidis, Nikolaos S

    2016-07-01

    This study focuses on the effect of experimental parameters on the removal of ranitidine (RAN) during ozonation and the identification of the formed transformation products (TPs). The influence of pH value, the initial concentrations, the inorganic and the organic matter on RAN's removal were evaluated. Results indicated high reactivity of RAN with molecular aqueous ozone. Initial ozone concentration and pH were proven the major process parameters. Alkaline pH values promoted degradation and overall mineralization. Dissolved organic matter reacts competitively to RAN with the oxidants (ozone and/or radicals), influencing the target compound's removal. The presence of inorganic ions in the matrix did not seem to affect RAN ozonation. A total of eleven TPs were identified and structurally elucidated, with the complementary use of both Reversed Phase (RP) and Hydrophilic Interaction Liquid Chromatography (HILIC) quadrupole time of flight tandem mass spectrometry (Q-ToF-MS/MS). Most of the TPs (TP-304, TP-315b, TP-299b, TP-333, TP-283) were generated by the attack of ozone at the double bond or the adjacent secondary amine, with the abstraction of NO2 moiety, forming TPs with an aldehyde group and an imine bond. Oxidized derivatives with a carboxylic group (TP-315a, TP-331a, TP-331b, TP-299a) were also formed. RAN S-oxide was identified as an ozonation TP (TP-330) and its structure was confirmed through the analysis of a reference standard. TP-214 was also produced during ozonation, through the CN bond rupture adjacent to the NO2 moiety. HILIC was used complementary to RP, either for the separation and identification of TPs with isomeric structures that may have been co-eluted in RPLC or for the detection of new TPs that were not eluted in the RP chromatographic system. Retention time prediction was used as a supporting tool for the identification of TPs and results were in accordance with the experimental ones in both RP and HILIC. PMID:27133934

  5. Operational O3M-SAF trace gas column products: GOME-2 ozone, NO2, BrO, SO2 and CH2O

    NASA Astrophysics Data System (ADS)

    Hao, Nan; Valks, Pieter; Loyola, Diego; de Smedt, Isabelle; van Roozendael, Michel; Theys, Nicolas; Rix, Meike; Koukouli, Mariliza; Balis, Dimitris; Lambert, Jean-Christopher; Pinardi, Gaia; Zimmer, Walter; Emmadi, Sunil

    This contribution focuses on the operational GOME-2 trace gas column products developed at the German Aerospace Centre, in the framework of EUMETSAT's Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF). We present an overview of the retrieval algorithms and exemplary results for ozone, NO2, BrO, SO2 and CH2O. These trace gas column products are retrieved with the GOME Data Processor (GDP) version 4.x algorithm and the UPAS system. Total ozone and NO2 are retrieved with the Differential Optical Absorption Spectroscopy (DOAS) method using the UV wavelength region around 330 nm and 435 nm respectively. An additional algorithm is applied to retrieve the tropospheric NO2 column for polluted con-ditions. The operational ozone and NO2 products are available for the users in near real time, i.e. within two hours after sensing. SO2 emissions from volcanic and anthropogenic sources can be measured by GOME-2 around 320 nm. For BrO and CH2O, optimal DOAS fitting windows have been determined for GOME-2 in the UV wavelength region. The GOME-2 ozone, total and tropospheric NO2, SO2, BrO, CH2O and cloud products from DLR have reached the operational EUMETSAT O3M-SAF status. All these products are routinely available to the users via EUMETCast, WMO/GTS and FTP in HDF5 and BUFR format. We present initial validation results for GOME-2 products using ground-based measurements, as well as comparisons with other satellite products, such as those from SCIAMACHY and OMI. The use of tropospheric NO2, SO2 and CH2O columns for air quality applications will be presented, including temporal evolution analyses for China. Furthermore, we will show examples of BrO under polar winter conditions.

  6. Rhythmic changes in ascorbic acid production in ozone-sensitive and tolerant soybean leaves in response to ozone stress

    SciTech Connect

    Lee, E.H.

    1986-04-01

    Relationships between foliar ozone (O/sub 3/) tolerance and leaf ascorbic acid (AA) concentrations in O/sub 3/-susceptible (O/sub 3/-S) Hark and O/sub 3/-resistant (O/sub 3/-R) Hood soybean cultivars were examined by high-performance liquid chromatography. Plants were grown in charcoal filtered (CF) and non-filtered (NF) air and leaf samples were analyzed at 4 h intervals during a 24 h period. Ascorbic acid concentrations showed a significant 24 h rhythm; during the day time, the highest AA levels in leaves coincided with the highest concentrations of photochemical oxidants in the atmosphere at 2:00 pm. In CF air both O/sub 3/-S and O/sub 3/-R cultivars showed AA production rhythms. In NF air the O/sub 3/-R cultivars retained this rhythm, but the O/sub 3/-S cultivar did not. Results indicated that superior O/sub 3/ tolerance in the Hood cultivar (compared with Hark) was associated with much greater increases in endogenous levels of AA which may scavenge free radicals and thereby protect cells from injury by O/sub 3/ or other oxyradical products.

  7. A comparison of biologically active filters for the removal of ozone by-products, turbidity, and particles

    SciTech Connect

    Coffey, B.M.; Krasner, S.W.; Sclimenti, M.J.; Hacker, P.A.; Gramith, J.T.

    1996-11-01

    Biofiltration tests were performed at the Metropolitan Water District of Southern California`s 5.5-mgd (21,000 m{sup 3}d) demonstration plant using two 400 ft{sup 2} (37 m{sup 2}) anthracite/sand filters and a 6 ft{sup 2} (0.56 m{sup 2}) granular activated carbon (GAC)/sand filter operated in parallel. The empty-bed contact time (EBCT) within the GAC and anthracite ranged from 2.1-3.1 min. The filters were evaluated based on (1) conventional filtration performance (turbidity, particle removal, and headloss); (2) removal of biodegradable ozone by-products (assimilable organic carbon [AOC], aldehydes, and aldoketoacids) after startup; (3) removal of biodegradable ozone by-products at steady state; and (4) resistance to short-term process upsets such as intermittent chlorination or filter out-of-service time. Approximately 80 percent formaldehyde removal was achieved by the anthracite/sand filter operated at a 2.1-min EBCT (6 gpm/ft{sup 2} [15 m/h]) within 8 days of ozone operation. The GAC/sand filter operated at the same rate achieved 80 percent removal within 1 day, possibly as an additive effect of adsorption and biological removal. In-depth aldehyde monitoring at four depths (0.5-min EBCT intervals) provided additional insight into the removal kinetics. During periods of warmer water temperature, from 20 to 48 percent of the AOC was removed in the flocculation/sedimentation basins by 40-75 percent. This percentage removal typically resulted in AOC concentrations within 40 {mu}g C/L of the raw, unozonated water levels.

  8. Evidence for an unidentified non-photochemical ground-level source of formaldehyde in the Po Valley with potential implications for ozone production

    NASA Astrophysics Data System (ADS)

    Kaiser, J.; Wolfe, G. M.; Bohn, B.; Broch, S.; Fuchs, H.; Ganzeveld, L. N.; Gomm, S.; Häseler, R.; Hofzumahaus, A.; Holland, F.; Jäger, J.; Li, X.; Lohse, I.; Lu, K.; Prévôt, A. S. H.; Rohrer, F.; Wegener, R.; Wolf, R.; Mentel, T. F.; Kiendler-Scharr, A.; Wahner, A.; Keutsch, F. N.

    2015-02-01

    Ozone concentrations in the Po Valley of northern Italy often exceed international regulations. As both a source of radicals and an intermediate in the oxidation of most volatile organic compounds (VOCs), formaldehyde (HCHO) is a useful tracer for the oxidative processing of hydrocarbons that leads to ozone production. We investigate the sources of HCHO in the Po Valley using vertical profile measurements acquired from the airship Zeppelin NT over an agricultural region during the PEGASOS 2012 campaign. Using a 1-D model, the total VOC oxidation rate is examined and discussed in the context of formaldehyde and ozone production in the early morning. While model and measurement discrepancies in OH reactivity are small (on average 3.4 ± 13%), HCHO concentrations are underestimated by as much as 1.5 ppb (45%) in the convective mixed layer. A similar underestimate in HCHO was seen in the 2002-2003 FORMAT Po Valley measurements, though the additional source of HCHO was not identified. Oxidation of unmeasured VOC precursors cannot explain the missing HCHO source, as measured OH reactivity is explained by measured VOCs and their calculated oxidation products. We conclude that local direct emissions from agricultural land are the most likely source of missing HCHO. Model calculations demonstrate that radicals from degradation of this non-photochemical HCHO source increase model ozone production rates by as much as 0.6 ppb h-1 (12%) before noon.

  9. Operational use of the AIRS Total Column Ozone Retrievals along with the RGB Airmass Product as Part of the GOES-R Proving Ground

    NASA Technical Reports Server (NTRS)

    Folmer, M.; Zavodsky, Bradley; Molthan, Andrew

    2012-01-01

    The Red, Green, Blue (RGB) Air Mass product has been demonstrated in the GOES ]R Proving Ground as a possible decision aid. Forecasters have been trained on the usefulness of identifying stratospheric intrusions and potential vorticity (PV) anomalies that can lead to explosive cyclogenesis, genesis of mesoscale convective systems (MCSs), or the transition of tropical cyclones to extratropical cyclones. It has also been demonstrated to distinguish different air mass types from warm, low ozone air masses to cool, high ozone air masses and the various interactions with the PV anomalies. To assist the forecasters in understanding the stratospheric contribution to high impact weather systems, the Atmospheric Infrared Sounder (AIRS) Total Column Ozone Retrievals have been made available as an operational tool. These AIRS retrievals provide additional information on the amount of ozone that is associated with the red coloring seen in the RGB Air Mass product. This paper discusses how the AIRS retrievals can be used to quantify the red coloring in RGB Air Mass product. These retrievals can be used to diagnose the depth of the stratospheric intrusions associated with different types of weather systems and provide the forecasters decision aid tools that can improve the quality of forecast products.

  10. Insights into the Electronic Structure of Ozone and Sulfur Dioxide from Generalized Valence Bond Theory: Addition of Hydrogen Atoms.

    PubMed

    Lindquist, Beth A; Takeshita, Tyler Y; Dunning, Thom H

    2016-05-01

    Ozone (O3) and sulfur dioxide (SO2) are valence isoelectronic species, yet their properties and reactivities differ dramatically. In particular, O3 is highly reactive, whereas SO2 is chemically relatively stable. In this paper, we investigate serial addition of hydrogen atoms to both the terminal atoms of O3 and SO2 and to the central atom of these species. It is well-known that the terminal atoms of O3 are much more amenable to bond formation than those of SO2. We show that the differences in the electronic structure of the π systems in the parent triatomic species account for the differences in the addition of hydrogen atoms to the terminal atoms of O3 and SO2. Further, we find that the π system in SO2, which is a recoupled pair bond dyad, facilitates the addition of hydrogen atoms to the sulfur atom, resulting in stable HSO2 and H2SO2 species. PMID:27070292

  11. Continuous ozonation treatment of ofloxacin: transformation products, water matrix effect and aquatic toxicity.

    PubMed

    Carbajo, Jose B; Petre, Alice L; Rosal, Roberto; Herrera, Sonia; Letón, Pedro; García-Calvo, Eloy; Fernández-Alba, Amadeo R; Perdigón-Melón, Jose A

    2015-07-15

    The continuous ozonation of the antibiotic ofloxacin (OFX) has been performed using a synthetic water matrix and in a sewage treatment plant (STP) effluent. The aim was to study the effect of the water matrix on the ozonation with particular emphasis on the aquatic toxicity of treated water. OFX was completely removed in both water matrices, although the amount of ozone consumed for its depletion was strongly matrix-dependent. The extent of mineralization was limited and a number of intermediate transformation products (TPs) appeared, twelve of which could be identified. OFX reaction pathway includes the degradation of piperazinyl and quinolone moieties. The further oxidation of TPs gave rise to the formation and accumulation of carboxylic acids, aldehydes, nitrogen-containing organic compounds and inorganic ions. Aquatic toxicity of treated mixtures was assessed using four standard species: the bacteria Vibrio fischeri and Pseudomonas putida as target organisms and the algae Pseudokirchneriella subcapitata and the protozoan Tetrahymena thermophila as non-target organisms. OFX was toxic for the bacteria and the microalgae at the spiked concentration in untreated water. However, the continuous ozonation at the upper operational limit removed its toxic effects. T. thermophila was not affected by OFX, but was sensitive to STP effluent. PMID:25796038

  12. A review of selected chemical additives in cosmetic products.

    PubMed

    Juhász, Margit Lai Wun; Marmur, Ellen S

    2014-01-01

    The addition of chemical additives to consumer cosmetic products is a common practice to increase cosmetic effectiveness, maintain cosmetic efficacy, and produce a longer-lasting, more viable product. Recently, manufacturers have come under attack for the addition of chemicals including dioxane, formaldehyde, lead/lead acetate, parabens, and phthalate, as these additives may prove harmful to consumer health. Although reports show that these products may indeed adversely affect human health, these studies are conducted using levels of the aforementioned chemicals at much higher levels of exposure than those found in cosmetic products. When cosmeceuticals are used as per manufacturer's instructions, it is estimated that the levels of harmful additives found in these products are considerably lower than reported toxic concentrations. PMID:25052592

  13. Study of ozone-initiated limonene reaction products by low temperature plasma ionization mass spectrometry.

    PubMed

    Nørgaard, Asger W; Vibenholt, Anni; Benassi, Mario; Clausen, Per Axel; Wolkoff, Peder

    2013-07-01

    Limonene and its ozone-initiated reaction products were investigated in situ by low temperature plasma (LTP) ionization quadrupole time-of-flight (QTOF) mass spectrometry. Helium was used as discharge gas and the protruding plasma generated ~850 ppb ozone in front of the glass tube by reaction with the ambient oxygen. Limonene applied to filter paper was placed in front of the LTP afterglow and the MS inlet. Instantly, a wide range of reaction products appeared, ranging from m/z 139 to ca. 1000 in the positive mode and m/z 115 to ca. 600 in the negative mode. Key monomeric oxidation products including levulinic acid, 4-acetyl-1-methylcyclohexene, limonene oxide, 3-isopropenyl-6-oxo-heptanal, and the secondary ozonide of limonene could be identified by collision-induced dissociation. Oligomeric products ranged from the nonoxidized dimer of limonene (C20H30) and up to the hexamer with 10 oxygen atoms (C60H90O10). The use of LTP for in situ ozonolysis and ionization represents a new and versatile approach for the assessment of ozone-initiated terpene chemistry. PMID:23666602

  14. Study of Ozone-Initiated Limonene Reaction Products by Low Temperature Plasma Ionization Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Nørgaard, Asger W.; Vibenholt, Anni; Benassi, Mario; Clausen, Per Axel; Wolkoff, Peder

    2013-07-01

    Limonene and its ozone-initiated reaction products were investigated in situ by low temperature plasma (LTP) ionization quadrupole time-of-flight (QTOF) mass spectrometry. Helium was used as discharge gas and the protruding plasma generated ~850 ppb ozone in front of the glass tube by reaction with the ambient oxygen. Limonene applied to filter paper was placed in front of the LTP afterglow and the MS inlet. Instantly, a wide range of reaction products appeared, ranging from m/ z 139 to ca. 1000 in the positive mode and m/ z 115 to ca. 600 in the negative mode. Key monomeric oxidation products including levulinic acid, 4-acetyl-1-methylcyclohexene, limonene oxide, 3-isopropenyl-6-oxo-heptanal, and the secondary ozonide of limonene could be identified by collision-induced dissociation. Oligomeric products ranged from the nonoxidized dimer of limonene (C20H30) and up to the hexamer with 10 oxygen atoms (C60H90O10). The use of LTP for in situ ozonolysis and ionization represents a new and versatile approach for the assessment of ozone-initiated terpene chemistry.

  15. Intercontinental Transport of Tropical Ozone from Biomass Burning: Views from Satellite and SHADOZ (Southern Hemisphere Additional Ozonesondes) Soundings

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.

    2003-01-01

    The atmospheric impacts of tropical fires came to attention in the 1970's and there has been interest in the connection between these fires and ozone since about 1980. Photochemically reactive gases released by fires (e.g. NO, CO, volatile organic carbon) interact as they do in an urban environment to form ozone. Tropical meteorology also plays a part in tropospheric ozone distributions in the tropics - through large-scale circulation, deep convection, regional phenomena (West African and Asian monsoon) - and variations associated with El-Nino and the Quasi- biennial Oscillation have been reported. This Poster is an overview of observations, taken from satellite and from ozone soundings, that illustrate regional influences and intercontinental-range ozone transport in the tropics.

  16. Fate and transformation products of amine-terminated PAMAM dendrimers under ozonation and irradiation.

    PubMed

    Santiago-Morales, Javier; Rosal, Roberto; Hernando, María D; Ulaszewska, Maria M; García-Calvo, Eloy; Fernández-Alba, Amadeo R

    2014-02-15

    This article deals with the degradation of a third-generation (G3) poly(amidoamine) (PAMAM) dendrimer under ozonation and irradiation. The identification and quantification of G3 PAMAM dendrimer and its transformation products has been performed by liquid chromatography-electrospray ionization-hybrid quadrupole time-of-flight-mass spectrometry. The dendrimer was completely depleted by ozone in less than 1 min. The effect of ultraviolet irradiation was attributed to hydroxyl-mediated oxidation. The transformation products were attributed to the oxidation of amines, which resulted in highly oxidized structures with abundance of carboxylic acids, which started from the formation of amine oxide and the scission of the CN bond of the amide group. We studied the toxicity of treated mixtures for six different organisms: the acute toxicity for the bacterium Vibrio fischeri and the microcrustacean Daphnia magna, the multigenerational growth inhibition of the alga Pseudokirchneriella subcapitata, and the seed germination phytotoxicity of Licopersicon esculentum, Lactuca sativa and Lolium perenne. Ozonation and irradiation originated transformation products are more toxic than the parent dendrimer. The toxicity of the dendrimer for the green alga was linked to a strong increase of intracellular reactive oxygen species with intense lipid peroxidation. PMID:24384376

  17. Secondary organic aerosol from ozone-initiated reactions with terpene-rich household products

    SciTech Connect

    Coleman, Beverly; Coleman, Beverly K.; Lunden, Melissa M.; Destaillats, Hugo; Nazaroff, William W.

    2008-01-01

    We analyzed secondary organic aerosol (SOA) data from a series of small-chamber experiments in which terpene-rich vapors from household products were combined with ozone under conditions analogous to product use indoors. Reagents were introduced into a continuously ventilated 198 L chamber at steady rates. Consistently, at the time of ozone introduction, nucleation occurred exhibiting behavior similar to atmospheric events. The initial nucleation burst and growth was followed by a period in which approximately stable particle levels were established reflecting a balance between new particle formation, condensational growth, and removal by ventilation. Airborne particles were measured with a scanning mobility particle sizer (SMPS, 10 to 400 nm) in every experiment and with an optical particle counter (OPC, 0.1 to 2.0 ?m) in a subset. Parameters for a three-mode lognormal fit to the size distribution at steady state were determined for each experiment. Increasing the supply ozone level increased the steady-state mass concentration and yield of SOA from each product tested. Decreasing the air-exchange rate increased the yield. The steady-state fine-particle mass concentration (PM1.1) ranged from 10 to> 300 mu g m-3 and yields ranged from 5percent to 37percent. Steady-state nucleation rates and SOA mass formation rates were on the order of 10 cm-3 s-1 and 10 mu g m-3 min-1, respectively.

  18. Ozone deposition velocities, reaction probabilities and product yields for green building materials

    NASA Astrophysics Data System (ADS)

    Lamble, S. P.; Corsi, R. L.; Morrison, G. C.

    2011-12-01

    Indoor surfaces can passively remove ozone that enters buildings, reducing occupant exposure without an energy penalty. However, reactions between ozone and building surfaces can generate and release aerosols and irritating and carcinogenic gases. To identify desirable indoor surfaces the deposition velocity, reaction probability and carbonyl product yields of building materials considered green (listed, recycled, sustainable, etc.) were quantified. Nineteen separate floor, wall or ceiling materials were tested in a 10 L, flow-through laboratory reaction chamber. Inlet ozone concentrations were maintained between 150 and 200 ppb (generally much lower in chamber air), relative humidity at 50%, temperature at 25 °C and exposure occurred over 24 h. Deposition velocities ranged from 0.25 m h -1 for a linoleum style flooring up to 8.2 m h -1 for a clay based paint; reaction probabilities ranged from 8.8 × 10 -7 to 6.9 × 10 -5 respectively. For all materials, product yields of C 1 thru C 12 saturated n-aldehydes, plus acetone ranged from undetectable to greater than 0.70 The most promising material was a clay wall plaster which exhibited a high deposition velocity (5.0 m h -1) and a low product yield (

  19. Ozone-initiated terpene reaction products in five European offices: replacement of a floor cleaning agent.

    PubMed

    Nørgaard, A W; Kofoed-Sørensen, V; Mandin, C; Ventura, G; Mabilia, R; Perreca, E; Cattaneo, A; Spinazzè, A; Mihucz, V G; Szigeti, T; de Kluizenaar, Y; Cornelissen, H J M; Trantallidi, M; Carrer, P; Sakellaris, I; Bartzis, J; Wolkoff, P

    2014-11-18

    Cleaning agents often emit terpenes that react rapidly with ozone. These ozone-initiated reactions, which occur in the gas-phase and on surfaces, produce a host of gaseous and particulate oxygenated compounds with possible adverse health effects in the eyes and airways. Within the European Union (EU) project OFFICAIR, common ozone-initiated reaction products were measured before and after the replacement of the regular floor cleaning agent with a preselected low emitting floor cleaning agent in four offices located in four EU countries. One reference office in a fifth country did not use any floor cleaning agent. Limonene, α-pinene, 3-carene, dihydromyrcenol, geraniol, linalool, and α-terpineol were targeted for measurement together with the common terpene oxidation products formaldehyde, 4-acetyl-1-methylcyclohexene (4-AMCH), 3-isopropenyl-6-oxo-heptanal (IPOH), 6-methyl-5-heptene-2-one, (6-MHO), 4-oxopentanal (4-OPA), and dihydrocarvone (DHC). Two-hour air samples on Tenax TA and DNPH cartridges were taken in the morning, noon, and in the afternoon and analyzed by thermal desorption combined with gas chromatography/mass spectrometry and HPLC/UV analysis, respectively. Ozone was measured in all sites. All the regular cleaning agents emitted terpenes, mainly limonene and linalool. After the replacement of the cleaning agent, substantially lower concentrations of limonene and formaldehyde were observed. Some of the oxidation product concentrations, in particular that of 4-OPA, were also reduced in line with limonene. Maximum 2 h averaged concentrations of formaldehyde, 4-AMCH, 6-MHO, and IPOH would not give rise to acute eye irritation-related symptoms in office workers; similarly, 6-AMCH, DHC and 4-OPA would not result in airflow limitation to the airways. PMID:25299176

  20. Measurements and modelling of ozone in the Mediterranean MBL: an investigation of the importance of ship emissions to local ozone production

    NASA Astrophysics Data System (ADS)

    Hedgecock, I. M.; Gencarelli, C. N.; Sch{ü}rmann, G. J.; Sprovieri, F.; Pirrone, N.

    2012-07-01

    Elevated concentrations of ground level ozone are both hazardous to human health and detrimental to agricultural production. The Mediterranean Basin, due to its position under the descending branch of the Hadley Cell circulation during the summer months, enjoys periods of stable, sunny and warm weather which provide ideal conditions for the production of ozone. The presence of major population centres and numerous industrialised areas in the coastal zone result in both a continual supply of ozone precursor compounds and also a significant number of people to suffer the consequences of high ozone concentrations. Using the WRF/Chem model validated with data obtained from seven oceanographic measurement campaigns, performed between 2000 and 2010, aboard the Italian Research Council's R. V. Urania, and also from a number of EMEP monitoring stations located around the Mediterranean Basin, the importance of emissions from maritime traffic in the region has been investigated. The model results indicate that over large areas of the Mediterranean emissions from shipping contribute between 5 and 10 ppb to the ground level O3 daily average concentration during the summer. The contribution to the hourly average O3 is up to 40 ppb in some particularly busy shipping lanes. Importantly the results suggest that in a number of coastal areas the contribution from ship emissions to the local O3 concentration can make the difference between complying with the EU Air Quality standard of a maximum 8 h mean of 120 μg m-3 and exceeding it.

  1. Elimination of micropollutants and transformation products from a wastewater treatment plant effluent through pilot scale ozonation followed by various activated carbon and biological filters.

    PubMed

    Knopp, Gregor; Prasse, Carsten; Ternes, Thomas A; Cornel, Peter

    2016-09-01

    Conventional wastewater treatment plants are ineffective in removing a broad range of micropollutants, resulting in the release of these compounds into the aquatic environment, including natural drinking water resources. Ozonation is a suitable treatment process for micropollutant removal, although, currently, little is known about the formation, behavior, and removal of transformation products (TP) formed during ozonation. We investigated the elimination of 30 selected micropollutants (pharmaceuticals, X-ray contrast media, industrial chemicals, and TP) by biological treatment coupled with ozonation and, subsequently, in parallel with two biological filters (BF) or granular activated carbon (GAC) filters. The selected micropollutants were removed to very different extents during the conventional biological wastewater treatment process. Ozonation (specific ozone consumption: 0.87 ± 0.29 gO3 gDOC(-1), hydraulic retention time: 17 ± 3 min) eliminated a large number of the investigated micropollutants. Although 11 micropollutants could still be detected after ozonation, most of these were eliminated in subsequent GAC filtration at bed volumes (BV) of approximately 25,000 m(3) m(-3). In contrast, no additional removal of micropollutants was achieved in the BF. Ozonation of the analgesic tramadol led to the formation of tramadol-N-oxide that is effectively eliminated by GAC filters, but not by BF. For the antiviral drug acyclovir, the formation of carboxy-acyclovir was observed during activated sludge treatment, with an average concentration of 3.4 ± 1.4 μg L(-1) detected in effluent samples. Subsequent ozonation resulted in the complete elimination of carboxy-acyclovir and led to the formation of N-(4-carbamoyl-2-imino-5-oxo imidazolidin)-formamido-N-methoxyacetetic acid (COFA; average concentration: 2.6 ± 1.0 μg L(-1)). Neither the BF nor the GAC filters were able to remove COFA. These results highlight the importance of considering TP in the

  2. 30 CFR 250.803 - Additional production system requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Additional production system requirements. 250.803 Section 250.803 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Production Safety Systems § 250.803...

  3. 15 CFR 1180.6 - Production of additional copies.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Production of additional copies. 1180.6 Section 1180.6 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade..., TECHNICAL AND ENGINEERING INFORMATION TO THE NATIONAL TECHNICAL INFORMATION SERVICE § 1180.6 Production...

  4. Elemental Bromine Production by TiO2 Photocatalysis and/or Ozonation.

    PubMed

    Parrino, Francesco; Camera Roda, Giovanni; Loddo, Vittorio; Palmisano, Leonardo

    2016-08-22

    Significant production of elemental bromine (Br2 ) was observed for the first time when treating bromide containing solutions at acidic pH, with TiO2 photocatalyst, ozone, or a combination thereof. Br2 selectivities up to approximately 85 % were obtained and the corresponding bromine mass balance values satisfied. The process is general and may be applied at a laboratory scale for green bromination reactions, or industrially as a cheap, safe, and environmentally sustainable alternative to the currently applied bromine production methods. PMID:27461437

  5. Assessment and Applications of NASA Ozone Data Products Derived from Aura OMI-MLS Satellite Measurements in Context of the GMI Chemical Transport Model

    NASA Technical Reports Server (NTRS)

    Ziemke, J. R.; Olsen, M. A.; Witte, J. C.; Douglass, A. R.; Strahan, S. E.; Wargan, K.; Liu, X.; Schoeberl, M. R.; Yang, K.; Kaplan, T. B.; Pawson, S.; Duncan, B. N.; Newman, P. A.; Bhartia, K.; Heney, M. K.

    2013-01-01

    Measurements from the Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS), both onboard the Aura spacecraft, have been used to produce daily global maps of column and profile ozone since August 2004. Here we compare and evaluate three strategies to obtain daily maps of tropospheric and stratospheric ozone from OMI and MLS measurements: trajectory mapping, direct profile retrieval, and data assimilation. Evaluation is based upon an assessment that includes validation using ozonesondes and comparisons with the Global Modeling Initiative (GMI) chemical transport model (CTM). We investigate applications of the three ozone data products from near-decadal and inter-annual timescales to day-to-day case studies. Zonally averaged inter-annual changes in tropospheric ozone from all of the products in any latitude range are of the order 1-2 Dobson Units while changes (increases) over the 8-year Aura record investigated http://eospso.gsfc.nasa.gov/atbd-category/49 vary approximately 2-4 Dobson Units. It is demonstrated that all of the ozone products can measure and monitor exceptional tropospheric ozone events including major forest fire and pollution transport events. Stratospheric ozone during the Aura record has several anomalous inter-annual events including stratospheric warming split events in the Northern Hemisphere extra-tropics that are well captured using the data assimilation ozone profile product. Data assimilation with continuous daily global coverage and vertical ozone profile information is the best of the three strategies at generating a global tropospheric and stratospheric ozone product for science applications.

  6. Process analysis and economics of drinking water production from coastal aquifers containing chromophoric dissolved organic matter and bromide using nanofiltration and ozonation.

    PubMed

    Sobhani, R; McVicker, R; Spangenberg, C; Rosso, D

    2012-01-01

    In regions characterized by water scarcity, such as coastal Southern California, groundwater containing chromophoric dissolved organic matter is a viable source of water supply. In the coastal aquifer of Orange County in California, seawater intrusion driven by coastal groundwater pumping increased the concentration of bromide in extracted groundwater from 0.4 mg l⁻¹ in 2000 to over 0.8 mg l⁻¹ in 2004. Bromide, a precursor to bromate formation is regulated by USEPA and the California Department of Health as a potential carcinogen and therefore must be reduced to a level below 10 μg l⁻¹. This paper compares two processes for treatment of highly coloured groundwater: nanofiltration and ozone injection coupled with biologically activated carbon. The requirement for bromate removal decreased the water production in the ozonation process to compensate for increased maintenance requirements, and required the adoption of catalytic carbon with associated increase in capital and operating costs per unit volume. However, due to the absence of oxidant addition in nanofiltration processes, this process is not affected by bromide. We performed a process analysis and a comparative economic analysis of capital and operating costs for both technologies. Our results show that for the case studied in coastal Southern California, nanofiltration has higher throughput and lower specific capital and operating cost, when compared to ozone injection with biologically activate carbon. Ozone injection with biologically activated carbon, compared to nanofiltration, has 14% higher capital cost and 12% higher operating costs per unit water produced while operating at the initial throughput. Due to reduced ozone concentration required to accommodate for bromate reduction, the ozonation process throughput is reduced and the actual cost increase (per unit water produced) is 68% higher for capital cost and 30% higher for operations. PMID:22054587

  7. Ozone production of hollow-needle-to-mesh negative corona discharge enhanced by dielectric tube on the needle electrode

    NASA Astrophysics Data System (ADS)

    Pekárek, Stanislav

    2014-12-01

    For the hollow-needle-to-mesh negative corona discharge in air, we studied the effect of placing the dielectric tube on the needle electrode and the effect of various positions of the end of this tube with respect to the tip of the needle electrode on the concentration of ozone produced by the discharge, the ozone production yield and the discharge V-A characteristics. We found that the placement of the dielectric tube on the needle electrode with a suitable position of this tube end with respect to the tip of the needle electrode for a particular discharge power led to a more than fourfold increase in the concentration of ozone produced by the discharge and also, for a constant airflow, the ozone production yield.

  8. The Application of TOMS Ozone, Aerosol and UV-B Data to Madagascar Air Quality Determination

    NASA Technical Reports Server (NTRS)

    Aikin, A.C.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Total Ozone Mapping Spectrometer (TOMS) data products for the area of Madagascar are presented. In addition to total ozone, aerosols and UV-B tropospheric ozone results are shown from 1979 to the present. Tropospheric ozone over Africa and Madagascar is enhanced by 10 to 15 DU in October. This maximum coincides with the time of maximum biomass area burning in Africa and Madagascar. Ozone observations were made from 1979 to 1999 using the TOMS tropospheric ozone convective cloud differential method. As a result of easterly trade winds, ozone originating on Madagascar is transported to the west over the Mozambique Channel. In El Nino years higher level westerly winds descend to transport low level ozone easterly. This results in African continental ozone being transported east of Madagascar. Long range transport of African ozone is observed during El Nino periods. The potential of TOMS and other space data for use in public education and research on Madagascar air quality is demonstrated.

  9. Novel anaerobic digestion process with sludge ozonation for economically feasible power production from biogas.

    PubMed

    Komatsu, K; Yasui, H; Goel, R; Li, Y Y; Noike, T

    2011-01-01

    A novel process scheme was developed to achieve economically feasible energy recovery from anaerobic digestion. The new process scheme employs a hybrid configuration of mesophilic and thermophilic anaerobic digestion with sludge ozonation: the ozonated sludge is first degraded in a thermophilic digester and then further degraded in a mesophilic digester. In small-scale pilot experiments of the new process scheme, degradation of VSS improved by 3.5% over the control (mesophilic-only configuration) with 20% less ozone consumption. Moreover, biogas conversion also improved by 7.1% over the control. Selective enrichment of inorganic compounds during centrifugation produced a dewatered sludge cake with very low water content (59.4%). This low water content in the sludge cake improved its auto-thermal combustion potential during incineration and added to the overall energy savings. We conducted a case study to evaluate power generation from biogas for a municipal wastewater treatment plant with an average dry weather flow of 43,000 m3/d. Electricity production cost was 5.2 ¢/kWh for the advanced process with power generation, which is lower than the current market price of 7.2 ¢/kWh. The new anaerobic digestion scheme with power generation may reduce greenhouse gas emissions by about 1,000 t-CO(2)/year compared with the conventional process without power generation. PMID:21508552

  10. Handbook of ozone technology and applications. Vol. 2. Ozone for drinking water treatment

    SciTech Connect

    Rice, R.G.; Netzer, A.

    1984-01-01

    This volume of the handbook series concerns the application of ozone for the treatment of drinking water. Great emphasis is given ozone's powerful disinfectant and oxidant properties with the added advantage of the non-production of undesirable by-products. European sources have been heavily drawn upon since that is where most of the experience has been. Over one-third of the volume is devoted to a bibliography of some 1600 citations (in addition to 260 as chapter references). Contents: Ozone disinfection of drinking water. Removal of color from drinking water with ozone. Removal of ammonia and other nitrogen derivatives from drinking water with ozone. Raw water preozonation. Recent developments in the treatment of drinking water. Ozone for drinking water treatment - a bibliography. Index.

  11. Free tropospheric ozone production following entrainment of urban plumes into deep convection

    NASA Technical Reports Server (NTRS)

    Pickering, Kenneth E.; Thompson, Anne M.; Scala, John R.; Tao, Wei-Kuo; Dickerson, Russell R.; Simpson, Joanne

    1992-01-01

    It is shown that rapid vertical transport of air from urban plumes through deep convective clouds can cause substantial enhancement of the rate of O3 production in the free troposphere. Simulation of convective redistribution and subsequent photochemistry of an urban plume from Oklahoma City during the 1985 PRESTORM campaign shows enhancement of O3 production in the free tropospheric cloud outflow layer by a factor of almost 4. In contrast, simulation of convective transport of an urban plume from Manaus, Brazil, into a prestine free troposphere during GTE/ABLE 2B (1987), followed by a photochemical simulation, showed enhancement of O3 production by a factor of 35. The reasons for the different enhancements are (1) intensity of cloud vertical motion; (2) initial boundary layer O3 precursor concentrations; and (3) initial amount of background free tropospheric NO(x). Convective transport of ozone precursors to the middle and upper troposphere allows the resulting O3 to spread over large geographic regions, rather than being confined to the lower troposphere where loss processes are much more rapid. Conversely, as air with lower NO descends and replaces more polluted air, there is greater O3 production efficiency per molecule of NO in the boundary layer following convective transport. As a result, over 30 percent more ozone could be produced in the entire tropospheric column in the first 24 hours following convective transport of urban plumes.

  12. Pomino: An Improved Satellite NO2 Product for the Ozone Monitoring Instrument

    NASA Astrophysics Data System (ADS)

    Lin, J.; Martin, R.; Boersma, K. F.; Sneep, M.; Stammes, P.; Spurr, R. J. D.; Wang, P.; Van Roozendael, M.; Clemer, K.; Irie, H.

    2014-12-01

    Tropospheric NO2 columns retrieved from satellite instruments are useful to infer NOx pollution, NOx emissions and atmospheric chemistry. Current satellite products are subject to limitations in assumptions of aerosol optical effects, surface reflectance anisotropy, vertical profiles of NO2, and/or cloud optical properties. Here we develop an improved Peking University Ozone Monitoring Instrument NO2 product (POMINO) for China, complementing the popular DONIMO v2 product. POMINO explicitly accounts for aerosol optical effects, angular dependence of surface reflectance, and dynamically varying atmospheric profiles of air pressure, air temperature and NO2 at a high horizontal resolution (50 km). Prior to the NO2 retrieval, we retrieve cloud top pressure and cloud fraction using consistent assumptions about the states of the atmosphere and surface. For our NO2 and cloud retrievals, we adopt from KNMI (via www.temis.nl) the SCDs of tropospheric NO2 (DOMINO v2) and O2-O2 dimer (OMCLDO2 v1.1.1.3), the TOA reflectance, and some other ancillary information. We develop the AMFv6 code for radiative transfer calculation, based on LIDORT v3.6. Radiative transfer is calculated explicitly for each satellite pixel with no need to use a look-up table. The calculation of AMFv6 is parallelized and is sufficiently fast so that one day of retrieval with global coverage would only take about three hours using 16 CPU cores. POMINO is consistent with MAX-DOAS NO2 data in China, with a R2of 0.96 as compared to the value at 0.72 for DOMINO v2. The improved consistency is related to explicit pixel-by-pixel radiative transfer calculation (instead of using a look-up table), consistent treatments of all parameters in retrieving clouds and NO2, explicit consideration of aerosol optical effects (rather than adjusting 'effective' clouds to implicitly account for aerosols), and consideration of surface reflectance anisotropy. Additional analyses are being conducted on the daily, seasonal and

  13. Variability in Ozone in the Tropical Upper Troposphere-Lower Stratosphere from the 1998-2000 SHADOZ (Southern Hemisphere Additional Ozonesondes) Data

    NASA Technical Reports Server (NTRS)

    Thompson, A. M.; Witte, J. C.; McPeters, R. D.; Schmidlin, F. J.; Oltmans, S. J.; Kirchhoff, V. W. J. H.; Coetzee, G. J. R.; Posny, F.; Kawakami, S.; Ogawa, T.; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    The first view of lower stratospheric and upper tropospheric structure from sondes is provided by a 3-year, 10-site record from the Southern Hemisphere ADditional OZonesondes (SHADOZ) network: . Observations covering 1998-2000 were made over Ascension Island; Nairobi, Kenya; Irene, South Africa; Reunion Island; Watukosek, Java; Fiji; Tahiti; American Samoa; San Cristobal, Galapagos; Natal, Brazil. Taking the UT/LS (upper troposphere- lower stratosphere) as the region between 12 and 17 km, we examine ozone variability in this region on a week-to-week and seasonal basis. The tropopause is lower in September-October-November than in March-April-May, when ozone is a minimum at most SHADOZ stations. A zonal wave-one pattern (referring to ozone mixing ratios greater over the Atlantic and adjacent continents than over the Pacific and eastern Indian Ocean), persists all year. The wave, predominantly in the troposphere and with variable magnitude, appears to be due to general circulation - with subsidence over the Atlantic and frequent deep convection over the Pacific and Indian Ocean. The variability of deep convection most prominent at Java, Fiji, Samoa and Natal - is explored in time-vs-altitude ozone curtains. Stratospheric incursions into the troposphere are most prominent in soundings at Irene and Reunion Island.

  14. Ozone production in the upper troposphere over West Africa: sensitivity to non-methane hydrocarbons under convective conditions

    NASA Astrophysics Data System (ADS)

    Bechara, Joelle; Borbon, Agnès.; Aumont, Bernard; Jambert, Corinne; Perros, Pascal

    2010-05-01

    Tropical deep convection is an efficient pathway of transporting up to the upper troposphere (UT) trace gas species such as volatile organic compounds (VOC). However, the impact of convective transport on UT composition and chemistry is still poorly characterized. The chemical impact of convection on the tropical UT over West Africa was studied during the AMMA Special Observation Period in August 2006 (SOP 2a2). Experimental strategy consisted in sampling at altitudes between 0 and 12 km downwind of Mesoscale Convective Systems (MCS) and at cloud base on-board the two French aircrafts, the ATR-42 and the French Falcon-20. Previous work pointed out that tropical deep convection in West Africa is efficient and is responsible with fast transport of VOC into the UT even the most reactive (isoprene) in less than one hour (Bechara et al., 2009). Here, we have investigated the impact of VOC precursors on ozone production. For that purpose, box modelling was implemented with the Master Chemical Mechanism scheme to simulate ozone variability in the upper troposphere downwind convection. The model is initialized with observed trace gases concentrations (NMHC, NOx, NOy, CO...) collected during the AMMA SOP 2a2 airborne campaign. Results show a positive ozone production several days downwind convective clouds at an average rate of 4 ppb/day. They confirm that UT ozone production is sensitive to NOx. Surprisingly, the sensitivity of NMHC initial concentrations on ozone production is negative. Indeed, an increase in NMHC favours PAN (peroxyacetyl nitrate) formation and thus decreases ozone production. The implication on ozone budget in the upper troposphere is crucial.

  15. Numerical modelling of ozone production in a wire-cylinder corona discharge and comparison with a wire-plate corona discharge

    NASA Astrophysics Data System (ADS)

    Wang, Pengxiang; Chen, Junhong

    2009-02-01

    The effect of electrode configuration on ozone production in the direct-current corona discharge of dry and humid air is studied by a numerical model that combines the electron distribution in the corona plasma, plasma chemistry and transport phenomena. Two electrode configurations are considered: wire-cylinder discharge with air flowing along the wire axis and wire-plate discharge with air flowing transverse to the wire. The ozone distributions in both types of discharges are compared. For both electrode configurations, the ozone production rate is higher in the negative corona than in the positive corona and it decreases with an increase in relative humidity. More importantly, the detailed ozone distribution in the neighbourhood of the discharge wire, together with the ozone kinetics, reveals the possible difference in the ozone production from the two discharges. With the same operating conditions and sufficiently short flow residence time, the ozone production rate is nearly the same for both electrode configurations. When the flow residence time is longer than the characteristic time for homogeneous ozone destruction, the net ozone production is higher in the wire-cylinder discharge than in the wire-plate discharge due to relatively less ozone destruction.

  16. Biogas Production on Demand Regulated by Butyric Acid Addition

    NASA Astrophysics Data System (ADS)

    Kasper, K.; Schiffels, J.; Krafft, S.; Kuperjans, I.; Elbers, G.; Selmer, T.

    2016-03-01

    Investigating effects of volatile fatty acids on the biogas process it was observed that butyric acid can be used for transient stimulation of the methane production in biogas plants operating with low energy substrates like cattle manure. Upon addition of butyrate the methane output of the reactors doubled within 24 h and reached almost 3-times higher methane yields within 3-4 days. Butyrate was quantitatively eliminated and the reactors returned to the original productivity state within 3 days when application of butyrate was stopped. The opportunity to use butyrate feeding for increased biogas production on demand is discussed.

  17. Effects of Asian air pollution transport and photochemistry on carbon monoxide variability and ozone production in subtropical coastal south China

    NASA Astrophysics Data System (ADS)

    Chan, C. Y.; Chan, L. Y.; Lam, K. S.; Li, Y. S.; Harris, J. M.; Oltmans, S. J.

    2002-12-01

    Surface ozone and carbon monoxide (CO) measured from a relatively remote coastal station in Hong Kong are analyzed to study the effects of pollutant transport and associated ozone production on CO and ozone variations in the subtropical south China region. CO and ozone concentrations show a common minimum in summer and in the maritime air masses from the South China Sea and Pacific Ocean. They have higher values in other seasons and in the continental air masses that have passed over mainland Asia and the East Asian coast. CO shows the maximum monthly median of 457-552 ppbv in winter while ozone shows a maximum of 40-50 ppbv in autumn and a distinct peak of 41-43 ppbv in spring. The CO concentrations especially in the continental air masses (median of 277 to 428 ppbv) are very high when compared with measurements in most parts of the world. This suggests that the south China region is under the strong influence of pollutant transport from the Asian continent and East Asian coast. Ozone and CO show strong positive correlations in the polluted maritime air masses and from late spring to early autumn (May-September) with the linear regression slopes of the ozone-CO plot from 0.08 to 0.22 (with respective standard errors from 0.01 to 0.03). The strong correlations and slopes plus the high CO levels indicate that there is substantial ozone production from pollution in the polluted maritime air masses and in the late spring to early autumn period.

  18. Sensitivity of model assessments of high-speed civil transport effects on stratospheric ozone resulting from uncertainties in the NO x production from lightning

    NASA Astrophysics Data System (ADS)

    Smyshlyaev, Sergei P.; Geller, Marvin A.; Yudin, Valery A.

    1999-11-01

    Lightning NOx production is one of the most important and most uncertain sources of reactive nitrogen in the atmosphere. To examine the role of NOx lightning production uncertainties in supersonic aircraft assessment studies, we have done a number of numerical calculations with the State University of New York at Stony Brook-Russian State Hydrometeorological Institute of Saint-Petersburg two-dimensional model. The amount of nitrogen oxides produced by lightning discharges was varied within its quoted uncertainty from 2 to 12 Tg N/yr. Different latitudinal, altitudinal, and seasonal distributions of lightning NOx production were considered. Results of these model calculations show that the assessment of supersonic aircraft impacts on the ozone layer is very sensitive to the strength of NOx production from lightning. The high-speed civil transport produced NOx leads to positive column ozone changes for lightning NOx production less than 4 Tg N/yr, and to total ozone decrease for lightning NOx production more than 5 Tg N/yr for the same NOx emission scenario. For large lightning production the ozone response is mostly decreasing with increasing emission index, while for low lightning production the ozone response is mostly increasing with increasing emission index. Uncertainties in the global lightning NOx production strength may lead to uncertainties in column ozone up to 4%. The uncertainties due to neglecting the seasonal variations of the lightning NOx production and its simplified latitude distribution are about 2 times less (1.5-2%). The type of altitude distribution for the lightning NOx production does not significally impact the column ozone, but is very important for the assessment studies of aircraft perturbations of atmospheric ozone. Increased global lightning NOx production causes increased total ozone, but for assessment of the column ozone response to supersonic aircraft emissions, the increase of lightning NOx production leads to column ozone

  19. 30 CFR 250.803 - Additional production system requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... reference as specified in 30 CFR 250.198). (b) Design, installation, and operation of additional production... CFR 250.198); (B) Determine that the unbonded flexible pipe is suitable for its intended purpose on... requirements of API Spec 17J (incorporated by reference as specified in 30 CFR 250.198). (3) Safety...

  20. 30 CFR 250.803 - Additional production system requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CFR 250.198). (b) Design, installation, and operation of additional production systems—(1) Pressure... with the requirements of API Spec 17J (incorporated by reference as specified in 30 CFR 250.198); (B... 17J (incorporated by reference as specified in 30 CFR 250.198). (3) Safety sensors. All...

  1. Pulmonary effects of inhaled limonene ozone reaction products in elderly rats

    SciTech Connect

    Sunil, Vasanthi R. . E-mail: sunilvr@eohsi.rutgers.edu; Laumbach, Robert J.; Patel, Kinal J.; Turpin, Barbara J.; Lim, Ho-Jin; Kipen, Howard M.; Laskin, Jeffrey D.; Laskin, Debra L.

    2007-07-15

    d-Limonene is an unsaturated volatile organic chemical found in cleaning products, air fresheners and soaps. It is oxidized by ozone to secondary organic aerosols consisting of aldehydes, acids, oxidants and fine and ultra fine particles. The lung irritant effects of these limonene ozone reaction products (LOP) were investigated. Female F344 rats (2- and 18-month-old) were exposed for 3 h to air or LOP formed by reacting 6 ppm d-limonene and 0.8 ppm ozone. BAL fluid, lung tissue and cells were analyzed 0 h and 20 h later. Inhalation of LOP increased TNF-{alpha}, cyclooxygenase-2, and superoxide dismutase in alveolar macrophages (AM) and Type II cells. Responses of older animals were attenuated when compared to younger animals. LOP also decreased p38 MAP kinase in AM from both younger and older animals. In contrast, while LOP increased p44/42 MAP kinase in AM from younger rats, expression decreased in AM and Type II cells from older animals. NF-{kappa}B and C/EBP activity also increased in AM from younger animals following LOP exposure but decreased or was unaffected in Type II cells. Whereas in younger animals LOP caused endothelial cell hypertrophy, perivascular and pleural edema and thickening of alveolar septal walls, in lungs from older animals, patchy accumulation of fluid within septal walls in alveolar sacs and subtle pleural edema were noted. LOP are pulmonary irritants inducing distinct inflammatory responses in younger and older animals. This may contribute to the differential sensitivity of these populations to pulmonary irritants.

  2. Effectiveness of Ozone with or without the Additional Use of Remineralizing Solution on Non-Cavitated Fissure Carious Lesions in Permanent Molars

    PubMed Central

    Atabek, Didem; Oztas, Nurhan

    2011-01-01

    Objectives: The aim of this study was to evaluate the efficiency of ozone alone and with a re-mineralizing solution following application on initial pit and fissure caries lesions in permanent molars. Methods: Forty children (9–12 years) having non-cavitated fissure caries lesions on bilateral 40 first permanent mandibular molar teeth were participated in the study. Patients were randomly allocated to 2 experimental groups consisting of 20 subjects. In the first group, ozone was applied once for 40 seconds to the assigned test teeth of each pair. In the second group, ozone was applied once for 40 seconds to the assigned test teeth of each pair with the use of re-mineralizing solution. Progression or improvement of the caries was assessed at baseline, immediately after treatment and at 1-,2-,3-, and 6 month follow-up by comparing the DIAGNOdent values, Clinical Severity Indexes, Oral Hygiene Scores. The results were analyzed statistically by using the Wilcoxon-Test for dependent samples in each group. When comparing different test groups (control and experimental groups) the Friedman S test followed by the Mann-Whitney U test was used. Results: A statistically significant difference was found between all of the control and experimental test lesions in each group (P<.001). However, there was no statistically significant difference between the ozone treated groups and those using the additional re-mineralizing solution (P>.001). Conclusions: Ozone treatment either alone or combined with a re-mineralizing solution was found to be effective for remineralization of initial fissure caries lesions. PMID:22654551

  3. Reducing viscosity of coal-liquefaction products with additives

    SciTech Connect

    Chao, T.S.; Kutta H.W.; Smith, A.C. Jr.

    1980-01-01

    A research program to investigate the cause of high viscosity of coal liquefaction products and to improve this critical property was carried out at Harvey Technical Center under the joint sponsorship by Electric Power Research Institute and Atlantic Richfield Company. Prior to this joint program an in-house project was also initiated by Atlantic Richfield to determine causes and remedies for high viscosity of coal liquefaction products. One result of these programs is the discovery that certain chemical compounds, when used at concentrations of 1 to 10%, are effective in reducing the melt viscosity and softening temperature of these coal liquefaction products. These compounds can be divided into two groups, reactive and unreactive additives. Acids, anhydrides, amides and epoxides fall in the reactive group, while pyrrolidines and compounds belonging to the chemical classes of amides, phosphoramides, lactams and ketones belong to the unreactive additives. This paper summarizes findings on this subject and explains the mechanism of action involved.

  4. Ozone production rates as a function of NOx abundances and HOx production rates in the Nashville urban plume

    NASA Astrophysics Data System (ADS)

    Thornton, J. A.; Wooldridge, P. J.; Cohen, R. C.; Martinez, M.; Harder, H.; Brune, W. H.; Williams, E. J.; Roberts, J. M.; Fehsenfeld, F. C.; Hall, S. R.; Shetter, R. E.; Wert, B. P.; Fried, A.

    2002-06-01

    Tropospheric O3 concentrations are functions of the chain lengths of NOx (NOx ≡ NO + NO2) and HOx (HOx ≡ OH + HO2 + RO2) radical catalytic cycles. For a fixed HOx source at low NOx concentrations, kinetic models indicate the rate of O3 production increases linearly with increases in NOx concentrations (NOx limited). At higher NOx concentrations, kinetic models predict ozone production rates decrease with increasing NOx (NOx saturated). We present observations of NO, NO2, O3, OH, HO2, H2CO, actinic flux, and temperature obtained during the 1999 Southern Oxidant Study from June 15 to July 15, 1999, at Cornelia Fort Airpark, Nashville, Tennessee. The observations are used to evaluate the instantaneous ozone production rate (PO3) as a function of NO abundances and the primary HOx production rate (PHOx). These observations provide quantitative evidence for the response of PO3 to NOx. For high PHOx (0.5 < PHOx < 0.7 ppt/s), O3 production at this site increases linearly with NO to ~500 ppt. PO3 levels out in the range 500-1000 ppt NO and decreases for NO above 1000 ppt. An analysis along chemical coordinates indicates that models of chemistry controlling peroxy radical abundances, and consequently PO3, have a large error in the rate or product yield of the RO2 + HO2 reaction for the classes of RO2 that predominate in Nashville. Photochemical models and our measurements can be forced into agreement if the product of the branching ratio and rate constant for organic peroxide formation, via RO2 + HO2 -> ROOH + O2, is reduced by a factor of 3-12. Alternatively, these peroxides could be rapidly photolyzed under atmospheric conditions making them at best a temporary HOx reservoir. This result implies that O3 production in or near urban areas with similar hydrocarbon reactivity and HOx production rates may be NOx saturated more often than current models suggest.

  5. Ozone, Tropospheric

    NASA Technical Reports Server (NTRS)

    Fishman, Jack

    1995-01-01

    In the early part of the 20th century, ground-based and balloon-borne measurements discovered that most of atmosphere's ozone is located in the stratosphere with highest concentrations located between 15 and 30 km (9,3 and 18.6 miles). For a long time, it was believed that tropospheric ozone originated from the stratosphere and that most of it was destroyed by contact with the earth's surface. Ozone, O3, was known to be produced by the photo-dissociation of molecular oxygen, O2, a process that can only occur at wavelengths shorter than 242 nm. Because such short-wave-length radiation is present only in the stratosphere, no tropospheric ozone production is possible by this mechanism. In the 1940s, however, it became obvious that production of ozone was also taking place in the troposphere. The overall reaction mechanism was eventually identified by Arie Haagen-Smit of the California Institute of Technology, in highly polluted southern California. The copious emissions from the numerous cars driven there as a result of the mass migration to Los Angeles after World War 2 created the new unpleasant phenomenon of photochemical smog, the primary component of which is ozone. These high levels of ozone were injuring vegetable crops, causing women's nylons to run, and generating increasing respiratory and eye-irritation problems for the populace. Our knowledge of tropospheric ozone increased dramatically in the early 1950s as monitoring stations and search centers were established throughout southern California to see what could be done to combat this threat to human health and the environment.

  6. Effects of ozone on net primary production and carbon sequestration in the conterminous United States using a biogeochemistry model

    NASA Astrophysics Data System (ADS)

    Felzer, B.; Kicklighter, D.; Melillo, J.; Wang, C.; Zhuang, Q.; Prinn, R.

    2004-07-01

    The effects of air pollution on vegetation may provide an important control on the carbon cycle that has not yet been widely considered. Prolonged exposure to high levels of ozone, in particular, has been observed to inhibit photosynthesis by direct cellular damage within the leaves and through possible changes in stomatal conductance. We have incorporated empirical equations derived for trees (hardwoods and pines) and crops into the Terrestrial Ecosystem Model to explore the effects of ozone on net primary production (NPP) and carbon sequestration across the conterminous United States. Our results show a 2.6 6.8% mean reduction for the United States in annual NPP in response to modelled historical ozone levels during the late 1980s-early 1990s. The largest decreases (over 13% in some locations) occur in the Midwest agricultural lands, during the mid-summer when ozone levels are highest. Carbon sequestration since the 1950s has been reduced by 18 38 Tg C yr-1 with the presence of ozone. Thus the effects of ozone on NPP and carbon sequestration should be factored into future calculations of the United States' carbon budget.

  7. Effect of ozonolysis pretreatment parameters on the sugar release, ozone consumption and ethanol production from sugarcane bagasse.

    PubMed

    Travaini, Rodolfo; Barrado, Enrique; Bolado-Rodríguez, Silvia

    2016-08-01

    A L9(3)(4) orthogonal array (OA) experimental design was applied to study the four parameters considered most important in the ozonolysis pretreatment (moisture content, ozone concentration, ozone/oxygen flow and particle size) on ethanol production from sugarcane bagasse (SCB). Statistical analysis highlighted ozone concentration as the highest influence parameter on reaction time and sugars release after enzymatic hydrolysis. The increase on reaction time when decreasing the ozone/oxygen flow resulted in small differences of ozone consumptions. Design optimization for sugars release provided a parameters combination close to the best experimental run, where 77.55% and 56.95% of glucose and xylose yields were obtained, respectively. When optimizing the grams of sugar released by gram of ozone, the highest influence parameter was moisture content, with a maximum yield of 2.98gSUGARS/gO3. In experiments on hydrolysates fermentation, Saccharomyces cerevisiae provided ethanol yields around 80%, while Pichia stipitis was completely inhibited. PMID:27132222

  8. GC/MS IDENTIFICATION OF DRINKING WATER DISINFECTION BY-PRODUCTS FROM MILWAUKEE'S NEW OZONATION PLANTS

    EPA Science Inventory

    The Milwaukee Water Works recently added ozonation disinfection facilities to their municipal drinking water treatment. Coupling ozone treatment with biologically active filtration (BAF) was seen as a logical step to enhance multiple water quality objectives (an effective barrier...

  9. Laboratory Experiments on the Electrochemical Remediation of the Environment. Part 7: Microscale Production of Ozone

    ERIC Educational Resources Information Center

    Ibanez, Jorge G.; Mayen-Mondragon, Rodrigo; Moran-Moran, M. T.; Alatorre-Ordaz, Alejandro; Mattson, Bruce; Eskestrand, Scot

    2005-01-01

    Ozone is a powerful oxidant and disinfectant, which can be used to clean environment as well as obtain pure drinking water. A series of experiments to produce and test ozone with simple equipment and material are presented.

  10. Production of mono- and di-carboxylated polyethylene glycols as a factor obstacle to the successful ozonation-assisted biodegradation of ethoxylated compounds.

    PubMed

    Nakai, Satoshi; Okuda, Tetsuji; Nishijima, Wataru; Okada, Mitsumasa

    2015-10-01

    Ozonation is believed to improve the biodegradability of organic compounds. In the present study, degradation of nonylphenol ethoxylates (NPEOs) was monitored in hybrid treatment systems consisting of ozonation and microbial degradation processes. We found that ozonation of NPEOs decreased, rather than increased, the biodegradability under certain conditions. The timing of ozonation was a definitive factor in determining whether ozonation increased or decreased the biodegradation rates of NPEOs. Initial ozonation of NPEOs prior to biodegradation reduced the rate of dissolved organic carbon (DOC) removal during the subsequent 14 d of biodegradation, whereas intermediate ozonation at the 9th day of biodegradation improved subsequent DOC removal during 14 d of NPEO biodegradation. Furthermore, reduction of DOC removal was also observed, when initial ozonation prior to biodegradation was subjected to cetyl alcohol ethoxylates. The production of less biodegradable intermediates, such as mono- and dicarboxylated polyethylene glycols (MCPEGs and DCPEGs), was responsible for the negative effect of ozonation on biodegradability of NPEOs. DCPEGs and MCPEGs were produced by biodegradation of polyethylene glycols (PEGs) that were ozonolysis products of the NPEOs, and the biodegradability of DCPEGs and MCPEGs was less than that of the precursor PEGs. The results indicate that, if the target chemicals contain ethoxy chains, production of PEGs may be one of the important factors when ozonation is considered. PMID:25985303

  11. Regional Attribution of Ozone Production and Associated Radiative Forcing: a Step to Crediting NOx Emission Reductions

    NASA Astrophysics Data System (ADS)

    Naik, V.; Mauzerall, D. L.; Horowitz, L.; Schwarzkopf, D.; Ramaswamy, V.; Oppenheimer, M.

    2004-12-01

    The global distribution of tropospheric ozone (O3) depends on the location of emissions of its precursors in addition to chemical and dynamical factors. The global picture of O3 forcing is, therefore, a sum of regional forcings arising from emissions of precursors from different sources. The Kyoto Protocol does not include ozone as a greenhouse gas, and emission reductions of ozone precursors made under Kyoto or any similar agreement would presently receive no credit. In this study, we quantitatively estimate the contribution of emissions of nitrogen oxides (NOx), the primary limiting O3 precursor in the non-urban atmosphere, from specific countries and regions of the world to global O3 concentration distributions. We then estimate radiative forcing resulting from the regional perturbations of NOx emissions. This analysis is intended as an early step towards incorporating O3 into the Kyoto Protocol or any successor agreement. Under such a system countries could obtain credit for improvements in local air quality that result in reductions of O3 concentrations because of the associated reductions in radiative forcing. We use the global chemistry transport model, MOZART-2, to simulate the global O3 distribution for base year 1990 and perturbations to this distribution caused by a 10% percent reduction in the base emissions of NOx from the United States, Europe, East Asia, India, South America, and Africa. We calculate the radiative forcing for the simulated base and perturbed O3 distributions using the GFDL radiative transfer model. The difference between the radiative forcing from O3 for the base and perturbed distributions provides an estimate of the marginal radiative forcing from a region's emissions of NOx. We will present a quantitative analysis of the magnitude, spatial, and temporal distribution of radiative forcing resulting from marginal changes in the NOx emissions from each region.

  12. Numerical modeling of ozone production in a pulsed homogeneous discharge: A parameter study

    SciTech Connect

    Nilsson, J.O.; Eninger, J.E.

    1997-02-01

    The pulsed volume discharge is an alternative for the efficient generation of ozone in compact systems. This paper presents a parameter study of the reactions in this kind of homogeneous discharge by using a numerical model which solves plasma chemical kinetic rate and energy equations. Results are presented of ozone generation efficiency versus ozone concentration for different parameter combinations. Two parameter regimes are identified and analyzed. In the plasma phase ozone formation regime, where significant amounts of ozone are produced during the discharge pulse, it is found that higher ozone concentrations can be obtained than in the neutral phase ozone formation regime, where most of the ozone is formed after the discharge pulse. In the two-step ozone formation process, the rate of conversion of atomic oxygen plays a key role. In both regimes the ozone generation efficiency increases as n is increased or T{sub 0} decreased. The maximum concentration is 3% at 10 amagat and 100 K. The results on ozone accumulation in multiple pulse discharges are presented. In contrast to the single pulse case, higher efficiency is achieved at lower gas density. This scaling can be explained by losses due to ion currents. A tradeoff can be made between ozone generation efficiency and the number of pulses required to reach a certain concentration.

  13. Ambient volatile organic compounds and their effect on ozone production in Wuhan, central China.

    PubMed

    Lyu, X P; Chen, N; Guo, H; Zhang, W H; Wang, N; Wang, Y; Liu, M

    2016-01-15

    Ambient volatile organic compounds (VOCs) were continuously measured from February 2013 to October 2014 at an urban site in Wuhan. The characteristics and sources of VOCs and their effect on ozone (O3) formation were studied for the first time. The total VOC levels in Wuhan were relatively low, and of all VOCs, ethane (5.2 ± 0.2 ppbv) was the species with the highest levels. Six sources, i.e., vehicular exhausts, coal burning, liquefied petroleum gas (LPG) usage, the petrochemical industry, solvent usage in dry cleaning/degreasing, and solvent usage in coating/paints were identified, and their contributions to the total VOCs were 27.8 ± 0.9%, 21.8 ± 0.8%, 19.8 ± 0.9%, 14.4 ± 0.9%, 8.5 ± 0.5%, and 7.7 ± 0.4%, respectively. Model simulation of a photochemical box model incorporating the Master Chemical Mechanism (PBM-MCM) indicated that the contribution to O3 formation of the above sources was 23.4 ± 1.3%, 22.2 ± 1.2%, 23.1 ± 1.7%, 11.8 ± 0.9%, 5.2 ± 0.4%, and 14.2 ± 1.1%, respectively. LPG and solvent usage in coating/paints were the sources that showed higher contributions to O3 formation, compared to their contributions to VOCs. The relative incremental reactivity (RIR) analysis revealed that the O3 formation in Wuhan was generally VOC-limited, and ethene and toluene were the primary species contributing to O3 production, accounting for 34.3% and 31.5% of the total RIR-weighted concentration, respectively. In addition, the contribution of CO to the O3 formation was remarkable. The C4 alkanes and alkenes from the LPG usage also significantly contributed to the O3 formation. The results can assist local governments in formulating and implementing control strategies for photochemical pollution. PMID:26410695

  14. Surface recombination of oxygen atoms in O2 plasma at increased pressure: II. Vibrational temperature and surface production of ozone

    NASA Astrophysics Data System (ADS)

    Lopaev, D. V.; Malykhin, E. M.; Zyryanov, S. M.

    2011-01-01

    Ozone production in an oxygen glow discharge in a quartz tube was studied in the pressure range of 10-50 Torr. The O3 density distribution along the tube diameter was measured by UV absorption spectroscopy, and ozone vibrational temperature TV was found comparing the calculated ab initio absorption spectra with the experimental ones. It has been shown that the O3 production mainly occurs on a tube surface whereas ozone is lost in the tube centre where in contrast the electron and oxygen atom densities are maximal. Two models were used to analyse the obtained results. The first one is a kinetic 1D model for the processes occurring near the tube walls with the participation of the main particles: O(3P), O2, O2(1Δg) and O3 molecules in different vibrational states. The agreement of O3 and O(3P) density profiles and TV calculated in the model with observed ones was reached by varying the single model parameter—ozone production probability (\\gamma_{O_{3}}) on the quartz tube surface on the assumption that O3 production occurs mainly in the surface recombination of physisorbed O(3P) and O2. The phenomenological model of the surface processes with the participation of oxygen atoms and molecules including singlet oxygen molecules was also considered to analyse \\gamma_{O_{3}} data obtained in the kinetic model. A good agreement between the experimental data and the data of both models—the kinetic 1D model and the phenomenological surface model—was obtained in the full range of the studied conditions that allowed consideration of the ozone surface production mechanism in more detail. The important role of singlet oxygen in ozone surface production was shown. The O3 surface production rate directly depends on the density of physisorbed oxygen atoms and molecules and can be high with increasing pressure and energy inputted into plasma while simultaneously keeping the surface temperature low enough. Using the special discharge cell design, such an approach opens up the

  15. 40 CFR Appendix H to Subpart A of... - Clean Air Act Amendments of 1990 Phaseout Schedule for Production of Ozone-Depleting Substances

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 17 2011-07-01 2011-07-01 false Clean Air Act Amendments of 1990 Phaseout Schedule for Production of Ozone-Depleting Substances H Appendix H to Subpart A of Part 82... STRATOSPHERIC OZONE Production and Consumption Controls Pt. 82, Subpt. A, App. H Appendix H to Subpart A of...

  16. Investigation of terpinolene + ozone or terpinolene + nitrate radical reaction products using denuder/filter apparatus

    NASA Astrophysics Data System (ADS)

    Harrison, Joel C.; Wells, J. R.

    2013-12-01

    Terpinolene's (1-methyl-4-(propan-2-ylidene)cyclohexene) reaction with ozone or the nitrate radical was investigated using a denuder/filter apparatus in order to characterize gas-phase and particulate reaction products. Identification of the reaction products (i.e., aldehydes, ketones, dicarbonyls and carboxylic acids) was made using two derivatization methods; O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) to derivatize the carbonyl products or 3-Ethyl-1-[3-(dimethylamino)propyl]carbodiimide hydrochloride (EDC) and 2,2,2-trifluoroethylamine hydrochloride (TFEA) to derivatize the carboxylic acid products. Proposed carbonyl products for ozonolysis of terpinolene are: 4-methylcyclohex-3-en-1-one, 2-hydroxy-4-methylcyclohex-3-en-1-one, glyoxal, methyl glyoxal, 3-oxobutanal, and 6-oxo-3-(propan-2-ylidene)heptanal. Proposed carbonyl products for nitrate radical reaction of terpinolene are: 2-hydroxy-4-methylcyclohex-3-en-1-one, glyoxal, methyl glyoxal, and 4-oxopentanal. No carboxylic acid products were detected with either oxidizing reactant.

  17. Investigation of terpinolene + ozone or terpinolene + nitrate radical reaction products using denuder/filter apparatus

    PubMed Central

    Harrison, Joel C.; Wells, J.R.

    2015-01-01

    Terpinolene’s (1-methyl-4-(propan-2-ylidene)cyclohexene) reaction with ozone or the nitrate radical was investigated using a denuder/filter apparatus in order to characterize gas-phase and particulate reaction products. Identification of the reaction products (i.e., aldehydes, ketones, dicarbonyls and carboxylic acids) was made using two derivatization methods; O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) to derivatize the carbonyl products or 3-Ethyl-1-[3-(dimethylamino)propyl]carbodiimide hydrochloride (EDC) and 2,2,2-trifluoroethylamine hydrochloride (TFEA) to derivatize the carboxylic acid products. Proposed carbonyl products for ozonolysis of terpinolene are: 4-methylcyclohex-3-en-1-one, 2-hydroxy-4-methylcyclohex-3-en-1-one, glyoxal, methyl glyoxal, 3-oxobutanal, and 6-oxo-3-(propan-2-ylidene)heptanal. Proposed carbonyl products for nitrate radical reaction of terpinolene are: 2-hydroxy-4-methylcyclohex-3-en-1-one, glyoxal, methyl glyoxal, and 4-oxopentanal. No carboxylic acid products were detected with either oxidizing reactant. PMID:26527171

  18. OZONE BYPRODUCT FORMATION

    EPA Science Inventory

    The use of ozone for water treatment has been increasing as ozone has great potential for degrading water pollutants and inactivating viruses, Giardia cysts, and Cryptosporidium oocysts. Although it appears that ozone generates less undesirable disinfection by-products (DBPs) th...

  19. In vitro ozone exposure increases release of arachidonic acid products from a human bronchial epithelial cell line

    SciTech Connect

    McKinnon, K.P.; Madden, M.C.; Noah, T.L.; Devlin, R.B. )

    1993-02-01

    Eicosanoids released after ozone exposure of a human bronchial epithelial cell line, BEAS-S6, were analyzed by high-pressure liquid chromatography (HPLC) of supernatants from exposed cells prelabeled with [3H]arachidonic acid. BEAS cells released thromboxane B2 (TxB2), prostaglandin E2 (PGE2), leukotriene C4 (LTC4), LTD4, LTE4, and 12-hydroxyheptadecatrienoic acid (HHT) after exposure to ozone at concentrations of 0.1, 0.25, 0.5, and 1.0 ppm. The eicosanoids were identified by coelution with authentic standards. The largest product from ozone-exposed BEAS cells was the most polar peak, designated Peak 1. Release of cyclooxygenase products such as TxB2, PGE2, and HHT was inhibited by acetylsalicylic acid. Peaks that migrated with authentic standards for LTB4, LTC4, and LTD4 were inhibited by the lipoxygenase inhibitor nordihydroguaiaretic acid. The leukotrienes LTB4 and LTC4/D4 could also be detected by immunoassay of concentrated peak fractions. Thus BEAS cells released eicosanoids from cyclooxygenase and lipoxygenase pathways of arachidonic acid metabolism following exposure to ozone. Airway epithelial cells may be an important source of eicosanoids following ozone stimulation in humans.

  20. Understanding High Wintertime Ozone Events over an Oil and Natural Gas Production Region from Air Quality Model Perspective

    NASA Astrophysics Data System (ADS)

    Ahmadov, R.; McKeen, S. A.; Trainer, M.; Banta, R. M.; Brown, S. S.; Edwards, P. M.; Frost, G. J.; Gilman, J.; Helmig, D.; Johnson, B.; Karion, A.; Koss, A.; Lerner, B. M.; Oltmans, S. J.; Roberts, J. M.; Schnell, R. C.; Veres, P. R.; Warneke, C.; Williams, E. J.; Wild, R. J.; Yuan, B.; Zamora, R. J.; Petron, G.; De Gouw, J. A.; Peischl, J.

    2014-12-01

    The huge increase in production of oil and natural gas has been associated with high wintertime ozone events over some parts of the western US. The Uinta Basin, UT, where oil and natural gas production is abundant experienced high ozone concentrations in winters of recent years, when cold stagnant weather conditions were prevalent. It has been very challenging for conventional air quality models to accurately simulate such wintertime ozone pollution cases. Here, a regional air quality model study was successfully conducted for the Uinta Basin by using the WRF-Chem model. For this purpose a new emission dataset for the region's oil/gas sector was built based on atmospheric in-situ measurements made during 2012 and 2013 field campaigns in the Uinta Basin. The WRF-Chem model demonstrates that the major factors driving high ozone in the Uinta Basin in winter are shallow boundary layers with light winds, high emissions of volatile organic compounds (VOC) compared to nitrogen oxides emissions from the oil and natural gas industry, enhancement of photolysis rates and reduction of O3 dry deposition due to snow cover. We present multiple sensitivity simulations to quantify the contribution of various factors driving high ozone over the Uinta Basin. The emission perturbation simulations show that the photochemical conditions in the Basin during winter of 2013 were VOC sensitive, which suggests that targeting VOC emissions would be most beneficial for regulatory purposes. Shortcomings of the emissions within the most recent US EPA (NEI-2011, version 1) inventory are also discussed.

  1. AGA; U. S. gas reserve additions lag production

    SciTech Connect

    Not Available

    1992-05-04

    The American Gas Association estimates 1991 U.S. natural gas reserve additions were only 65-79% of production, compared with a 96% average for 1981-90. AGA found that 75% of 1991 reserve additions occurred as discoveries and field extensions, and only 25% came from revisions of estimates. Total reserve additions may range from 11.1 tcf to 13.4 tcf. The 30 largest gas reserves holders sold more than 1.1 tcf of reserves to other firms. The top 30 companies had reserve additions of 5.754 tcf, down 3.541 tcf from a year earlier. Total gas reserves held by the top 30 dropped by 3.757 tcf. The 30 companies produced 8.417 tcf in 1991, compared with 8.352 tcf in 1989. This paper reports that AGA compiles the reserve addition estimates from data the 30 largest gas companies file with the Securities and exchange Commission, supplemented with data from gas pipelines holding large reserves.

  2. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  3. Exploring the Production of NOx by Lightning and Its Impact on Tropospheric Ozone

    NASA Technical Reports Server (NTRS)

    Gillani, Noor; Koshak, William; Biazar, Arastoo; Doty, Kevin; Mahon, Robert; Newchurch, Michael; Byun, Daewon; Emmons, Louisa

    2006-01-01

    Our quantitative understanding of free tropospheric (FT) chemistry is quite poor. State-of-the-art regional air quality models (e.g., US EPA's CMAQ) perform very poorly in simulating FT chemistry, with Uniform ozone around 70 ppb throughout the FT in summer, while ozonesonde data show much higher levels of ozone and much spatial-temporal structure. Such models completely neglect lightning-NOx (LNOx) emissions (the most significant source of NOx in the FT), and also contain large uncertainties in the specifications of intercontinental transport, stratosphere-troposphere exchange (STE) and PBLFT exchange (PFTE). Global air chemistry models include LNOx, but in very crude fashion, with the frequency and distribution of lightning being based on modeled cloud parameters (hence large uncertainty), lightning energetics being assumed to be constant for all flashes (literature value, while in reality there is at least a two-orders of magnitude variability from flash-to-flash), and the production of NOx in the surrounding heated air, per Joule of heating, being assumed to be constant also (literature value, while in fact it is a non-linear function of the dissipated heat and local air density, p). This situation is commonly blamed on paucity of pertinent observational data, but for the USA, there is now a wealth of surface- and satellite-based data of lightning available to permit much improved observation-based estimation of LNOx emissions. In the FT, such NOx has a long residence time, and also the ozone production efficiency from NOx there is considerably higher than in the PBL. It is, therefore, of critical importance in FT chemistry. This paper will describe the approach and data products of an ongoing NSSTC project aimed at a much-improved quantification of not only LNOx production on the scale of continental USA based on local and regional lightning observations, but also of intercontinental transport, STE and PFTE, all in upgraded simulations of tropospheric

  4. Identification of antiyellowing agents as precursors of N-nitrosodimethylamine production on ozonation from sewage treatment plant influent.

    PubMed

    Kosaka, Koji; Asami, Mari; Konno, Yusuke; Oya, Masami; Kunikane, Shoichi

    2009-07-15

    In Japan, N-nitrosodimethylamine (NDMA) formation associated with ozonation at a relatively high concentration has been reported only at a small number of water treatment plants (WTPs) in the western part of Japan for which the source water is the Yodo River. In the present study, the formation of relatively high concentrations of NDMA was found upon ozonation of water samples taken from sewage treatment plants (STPs) located upstream of the water intake points of the WTPs in the Yodo River basin. NDMA concentrations before and after ozonation were 16-290 and 14-280 ng/L, respectively. At least some of the STPs investigated receive industrial effluents. At one STP in this area, an extremely high concentration of NDMA (10,000ng/L) was found in one influent water sample after ozonation. To identify potential NDMA precursors upon ozonation in the influent at this STP, the concentrated extracts of the influent were fractionated by high-performance liquid chromatography (HPLC). Ultraperformance liquid chromatography coupled with tandem mass spectrometry (UPLC/MS/MS) identified 4,4'-hexamethylenebis(1,1-dimethylsemicarbazide) (HDMS) and 1,1,1',1'-tetramethyl-4,4'-(methylene-di-p-phenylene)disemicarbazide (TMDS) as precursors of NDMA on ozonation of the influent. Both HDMS and TMDS are used as antiyellowing agents in polyurethane fibers and as light stabilizers in polyamide resins. Their contributions to NDMA production on ozonation of water samples at STPs were up to 17%. The remaining unidentified NDMA precursors may be hydrophilic compounds that were not trapped by the cartridges used for extraction of the water samples. HDMS and TMDS were frequently present in surface waters and STP effluents in the Yodo River basin and were also detected in surface waters from several other areas in Japan. PMID:19708347

  5. 16 CFR 260.11 - Ozone-safe and ozone-friendly claims.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... friendly to, the ozone layer or the atmosphere. Example 1: A product is labeled “ozone-friendly.” The claim... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Ozone-safe and ozone-friendly claims. 260.11... THE USE OF ENVIRONMENTAL MARKETING CLAIMS § 260.11 Ozone-safe and ozone-friendly claims. It...

  6. 16 CFR 260.11 - Ozone-safe and ozone-friendly claims.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... friendly to, the ozone layer or the atmosphere. Example 1: A product is labeled “ozone-friendly.” The claim... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Ozone-safe and ozone-friendly claims. 260.11... THE USE OF ENVIRONMENTAL MARKETING CLAIMS § 260.11 Ozone-safe and ozone-friendly claims. It...

  7. THE GAS PHASE REACTION OF OZONE WITH 1,3-BUTADIENE: FORMATION YIELDS OF SOME TOXIC PRODUCTS. (R826236)

    EPA Science Inventory

    The formation yields of acrolein, 1,2-epoxy-3-butene and OH radicals have been measured from reaction of ozone with 1,3-butadiene at room temperature and atmosphere pressure. 1,3,5-Trimethyl benzene was added to scavenge OH radicals in measurements of product yields. In separa...

  8. O(D-1) production in ozone photolysis near 310 nm

    NASA Technical Reports Server (NTRS)

    Lin, C.; Demore, W. B.

    1973-01-01

    Relative quantum yields of O(D-1)production, phi, in ozone photolysis from 275 nm to 334 nm were determined in the gas phase at 233 K. The O(D-1) was monitored by means of its reaction with isobutane to form isobutyl alcohol. The light source was a high pressure mercury lamp combined with a monochromator, with a bandwidth of 1.6 nm. The results show a constant phi below 300 nm, which is taken as unity on the basis of previous work. There is a very sharp fall-off in phi which is centered at 308 nm. At 313 nm phi is not greater than 0.1.

  9. A quantum yield determination of O/1D/ production from ozone via laser flash photolysis

    NASA Technical Reports Server (NTRS)

    Philen, D. L.; Davis, D. D.; Watson, R. T.

    1977-01-01

    The quantum yield of electronically excited atomic oxygen produced from ozone photolysis was measured at 298 K from wavelengths of 293.0 to 316.5 nm. The reaction of the atomic oxygen with N2O to form excited NO2 was used to monitor the O production; a frequency-doubled flashlamp-pumped dye laser which provided tunable ultraviolet in the desired spectral region with 0.1-nm linewidth served as the photolysis source. The atomic oxygen quantum yield was found to be constant below 300 nm, with a sharp decrease centered at 308 nm and a diminution to less than one tenth of the constant value by 313.5 nm.

  10. Impacts of Oil and Gas Production on Winter Ozone Pollution in the Uintah Basin Using Model Source Apportionment

    NASA Astrophysics Data System (ADS)

    Tran, H. N. Q.; Tran, T. T.; Mansfield, M. L.; Lyman, S. N.

    2014-12-01

    Contributions of emissions from oil and gas activities to elevated ozone concentrations in the Uintah Basin - Utah were evaluated using the CMAQ Integrated Source Apportionment Method (CMAQ-ISAM) technique, and were compared with the results of traditional budgeting methods. Unlike the traditional budgeting method, which compares simulations with and without emissions of the source(s) in question to quantify its impacts, the CMAQ-ISAM technique assigns tags to emissions of each source and tracks their evolution through physical and chemical processes to quantify the final ozone product yield from the source. Model simulations were performed for two episodes in winter 2013 of low and high ozone to provide better understanding of source contributions under different weather conditions. Due to the highly nonlinear ozone chemistry, results obtained from the two methods differed significantly. The growing oil and gas industry in the Uintah Basin is the largest contributor to the elevated zone (>75 ppb) observed in the Basin. This study therefore provides an insight into the impact of oil and gas industry on the ozone issue, and helps in determining effective control strategies.

  11. On the Temperature Dependence of Organic Reactivity, Ozone Production, and the Impact of Emissions Controls in San Joaquin Valley California

    NASA Astrophysics Data System (ADS)

    Pusede, S. E.; Gentner, D. R.; Wooldridge, P. J.; Browne, E. C.; Min, K.; Rollins, D. W.; Russell, A.; Thomas, J.; Zhang, L.; Brune, W. H.; Henry, S. B.; DiGangi, J. P.; Keutsch, F. N.; Harrold, S.; Thornton, J. A.; Beaver, M. R.; St Clair, J. M.; Wennberg, P. O.; Ren, X.; Sanders, J.; VandenBoer, T. C.; Markovic, M. Z.; Guha, A.; Weber, R.; Goldstein, A. H.; Cohen, R. C.

    2013-12-01

    The San Joaquin Valley (SJV) experiences some of the worst ozone air quality in the U.S., frequently exceeding the California 8-h standard of 70.4 ppb. To improve our understanding of trends in the number of ozone violations in the SJV, we investigate observed relationships between organic reactivity, nitrogen oxides (NOx), and daily maximum temperature in the southern SJV using measurements made as part of California at the Nexus of Air Quality and Climate Change in 2010 (CalNex-SJV). We find the daytime speciated organic reactivity with respect OH during CalNex-SJV has a temperature-independent portion with molecules typically associated with motor vehicles being the major component. At high temperatures, characteristic of days with high ozone, the majority of the organic reactivity increases exponentially with temperature and is dominated by small oxygenated organics and molecules that are unidentified. We use this simple temperature classification to consider changes in organic emissions over the last and next decade. With the CalNex-SJV observations as constraints, we examine the sensitivity of ozone production (PO3) to future NOx and organic reactivity controls, finding that PO3 is NOx-limited at all temperatures on weekends and on weekdays when daily maximum temperatures are greater than 28oC. As a consequence, we show NOx reductions are the most effective control option for reducing the frequency of ozone violations in the southern SJV.

  12. Information content of satellite retrievals of HCHO and NO2 for constraining ozone production efficiency

    NASA Astrophysics Data System (ADS)

    Boeke, N.; Marshall, J. D.; Millet, D. B.

    2011-12-01

    We apply retrievals of vertical column abundance of formaldehyde (HCHO) and nitrogen dioxide (NO2) from the Ozone Monitoring Instrument (OMI) with the GEOS-Chem model to evaluate the information content of the satellite data for constraining local photochemistry and ozone production efficiency (OPE = P(Ox)/L(NOx) ~ P(RO2)/L(NOx)). Our study domain comprises North America and China, two regions that include major anthropogenic and biogenic emission sources. Simulated HCHO columns correlate strongly with odd oxygen and peroxy radical production rates (P(Ox) and P(RO2)) over both regions (r spans the range 0.67±0.25 to 0.75±0.15 across seasons/regions). Simulated NO2 columns correlate well with NOx loss rates (L(NOx)) (|r| ≥ 0.78±0.21 on average). Regression slopes for simulated P(RO2):HCHO and L(NOx):NO2 vary geographically and seasonally. Applying these modeled relationships to the OMI HCHO and NO2 retrievals we estimate OPE over North America and China. The amount of information provided by the satellite data to the OPE calculation increases with decreasing OPE. The NO2 column measurements dominate the calculation over land (providing > 40% of the signal in all seasons). During summer, the HCHO satellite observations account for on average ~25% of the OPE signal, comparable to the amount of information provided by the model. Using the unmodified HCHO:NO2 column ratio from the satellite observations as an index for OPE tends to over predict NOx sensitivity in regions with strong isoprene emissions relative to other areas.

  13. Advanced treatment of oilfield production wastewater by an integration of coagulation/flotation, catalytic ozonation and biological processes.

    PubMed

    Chen, Ke-Yong; Zhang, Xiao-Bing; Li, Jun

    2016-10-01

    In this study, advanced treatment of heavily polluted oilfield production wastewater (OPW) was investigated employing the combination of coagulation/dissolved air flotation, heterogeneous catalytic ozonation and sequencing batch reactor (SBR) processes. Two SBR reactors were separately set up before and after the ozonation unit. The results show that microbubble flotation was more efficient than macrobubble flotation in pollutant removal. Catalytic ozonation with the prepared Fe/activated carbon catalyst significantly enhanced pollutant removal in the second SBR by improving wastewater biodegradability and reducing wastewater microtoxicity. The treatment technique decreased oil, chemical oxygen demand and NH3-N by about 97%, 88% and 91%, respectively, allowing the discharge limits to be met. Therefore, the integrated process with efficient, economical and sustainable advantages was suitable for advanced treatment of real OPW. PMID:26936286

  14. Smog control fuel additives

    SciTech Connect

    Lundby, W.

    1993-06-29

    A method is described of controlling, reducing or eliminating, ozone and related smog resulting from photochemical reactions between ozone and automotive or industrial gases comprising the addition of iodine or compounds of iodine to hydrocarbon-base fuels prior to or during combustion in an amount of about 1 part iodine per 240 to 10,000,000 parts fuel, by weight, to be accomplished by: (a) the addition of these inhibitors during or after the refining or manufacturing process of liquid fuels; (b) the production of these inhibitors for addition into fuel tanks, such as automotive or industrial tanks; or (c) the addition of these inhibitors into combustion chambers of equipment utilizing solid fuels for the purpose of reducing ozone.

  15. MULTIPOLLUTANT METHODS - METHODS FOR OZONE AND OZONE PRECURSORS

    EPA Science Inventory

    This task involves the development and testing of methods for monitoring ozone and compounds associated with the atmospheric chemistry of ozone production both as precursors and reaction products. Although atmospheric gases are the primary interest, separation of gas and particl...

  16. Quantifying the contributions of individual NO x sources to the trend in ozone radiative forcing

    NASA Astrophysics Data System (ADS)

    Dahlmann, K.; Grewe, V.; Ponater, M.; Matthes, S.

    2011-06-01

    Source attribution of ozone radiative forcing (RF) is a prerequisite for developing adequate emission mitigation strategies with regards to climate impact. Decadal means of ozone fields from transient climate-chemistry simulations (1960-2019) are analysed and the temporal development of ozone RF resulting from individual NO x sources, e.g. road traffic, industry and air traffic, is investigated. We calculated an ozone production efficiency which is mainly dependent on the altitude of NO x emission and on the amount of background NO x with values varying over one order of magnitude. Air traffic and lightning are identified as NO x sources with a two and five times higher ozone production efficiency, respectively, than ground based sources. Second, radiative efficiency of source attributed ozone (i.e. total induced radiative flux change per column ozone) shows clear dependence on latitudinal structure of the ozone anomaly and, to a lesser extent, to its altitude. Lightning induced ozone shows the highest radiative efficiency because lightning primarily enhances ozone in low latitudes in the mid-troposphere (higher altitudes). Superimposed on these effects, a saturation effect causes a decreasing radiative efficiency with increasing background ozone concentrations. Changes in RF attributed to NO x induced ozone from 1960 to 2019 are controlled by three factors: changes in emissions, changes in ozone production efficiency and changes in the radiative efficiency. Leading effect is emission increase, but changes in ozone production efficiency increase ozone RF by a factor of three for air traffic, or reduce ozone RF by around 30% for ships. Additionally, changes in the radiative efficiency due to saturation effects change ozone RF by 2-5%.

  17. Production scheduling with discrete and renewable additional resources

    NASA Astrophysics Data System (ADS)

    Kalinowski, K.; Grabowik, C.; Paprocka, I.; Kempa, W.

    2015-11-01

    In this paper an approach to planning of additional resources when scheduling operations are discussed. The considered resources are assumed to be discrete and renewable. In most research in scheduling domain, the basic and often the only type of regarded resources is a workstation. It can be understood as a machine, a device or even as a separated space on the shop floor. In many cases, during the detailed scheduling of operations the need of using more than one resource, required for its implementation, can be indicated. Resource requirements for an operation may relate to different resources or resources of the same type. Additional resources are most often referred to these human resources, tools or equipment, for which the limited availability in the manufacturing system may have an influence on the execution dates of some operations. In the paper the concept of the division into basic and additional resources and their planning method was shown. A situation in which sets of basic and additional resources are not separable - the same additional resource may be a basic resource for another operation is also considered. Scheduling of operations, including greater amount of resources can cause many difficulties, depending on whether the resource is involved in the entire time of operation, only in the selected part(s) of operation (e.g. as auxiliary staff at setup time) or cyclic - e.g. when an operator supports more than one machine, or supervises the execution of several operations. For this reason the dates and work times of resources participation in the operation can be different. Presented issues are crucial when modelling of production scheduling environment and designing of structures for the purpose of scheduling software development.

  18. Use of ethylenediurea to detect effects of ambient ozone on biomass production by clover cultivars

    SciTech Connect

    Manning, W.; Johnson, M.; Frenkel, M.

    1995-12-31

    Ozone-tolerant (NCR) and ozone-sensitive (NCS) clonal plants of ladino white clover (Trifolium repens) were grown in 15-liter pots filled with a peat/perlite artificial growing medium during the 1994 and 1995 growing seasons. All plants were exposed to ambient concentrations of ozone. Beginning the first day plants were in the field, and continuing at 7-day intervals until final harvests, each plant was sprayed with 300 ppm ethylenediurea (EDU). Foliar biomass harvests were made at 28-day intervals and dry weights of leaves/stems determined. Biomass weights for NCR were unaffected by EDU. EDU ameliorated the effects of ambient ozone on NCR plants, allowing detection of the effects of ozone on an ozone-sensitive clone of white clover.

  19. Plant resistance mechanisms to air pollutants: rhythms in ascorbic acid production during growth under ozone stress

    SciTech Connect

    Lee, E.H. )

    1991-01-01

    Relationships between ozone (O3) tolerance and leaf ascorbic acid concentrations in O3-susceptible (O3-S) 'Hark' and O3-resistant (O3-R) 'Hood' soybean, Glycine max (L.) Merr., cultivars were examined with high-performance liquid chromatography (HPLC). Leaf samples were analyzed at 4 intervals during a 24 h period. Soybean cultivars grown in the greenhouse with charcoal filtered (CF) and nonfiltered (NF) air showed daily oscillations in ascorbic acid production. Highest ascorbic acid levels in leaves during light coincided with highest concentrations of photochemical oxidants in the atmosphere at 2:00 p.m. The resistant genotype produced more ascorbic acid in its trifoliate leaves than did the corresponding susceptible genotype. Under CF air (an O3-reduced environment) O3-S and O3-R cultivars showed rhythms in ascorbic acid production. In NF air (an O3 stress environment) the O3-R cultivar alone showed rhythms in ascorbic acid production. Results indicated that superior O3 tolerance in the Hood soybean cultivar (compared with Hark) was associated with a greater increase in endogenous levels of ascorbic acid. Ascorbic acid may scavenge free radicals and thereby protect cells from injury by O3 or other oxyradical products. Plants defend themselves against photochemical oxidant stress, such as O3, by several mechanisms. Experimental evidence indicates that antioxidant defense systems existing in plant tissues may function to protect cellular components from deleterious effects of photochemical oxidants through endogenous and exogenous controls.

  20. High-resolution MS and MS(n) investigation of ozone oxidation products from phenazone-type pharmaceuticals and metabolites.

    PubMed

    Favier, Maxime; Dewil, Raf; Van Eyck, Kwinten; Van Schepdael, Ann; Cabooter, Deirdre

    2015-10-01

    Phenazone-type pharmaceuticals, such as aminopyrine, metamizole, phenazone and propyphenazone, are widely used analgesics that have been detected in wastewater treatment plant effluents in μg L(-1) concentrations. Acetamido antipyrine (AAA) and formyl aminoantipyrine (FAA) - the main metabolites of aminopyrine and metamizole - have also been detected in sub μg L(-1) concentrations in environmental water bodies and in resources used to produce drinking water, suggesting their highly persistent character. In this study phenazone, propyphenazone, AAA and FAA were treated with ozone under laboratory conditions and 17 degradation products were identified by an elucidation approach based on high-resolution mass spectrometry (LTQ Orbitrap). Typical oxidation of carbon-carbon double bonds by ozone was observed among other mechanisms of ring opening. It was demonstrated that reactivity of these compounds with ozone is high (rate constants kO3 ranging from 6.5×10(4) to 2.4×10(6) M(-1) s(-1)). The toxicity of the degradation products from ozonation was estimated by quantitative structure-activity relationships (QSAR). It was shown that, when the carbon-carbon double bond is partially oxidized to an epoxy, the toxicity towards fish and daphnids is higher than that of the parent compound. By further oxidizing the molecules, a common degradation product - 1-acetyl-1-methyl-2-phenylhydrazide (AMPH) - was also found to be more toxic than its parent compounds, which is of concern since this compound has previously been reported in environmental waters. PMID:25935697

  1. Atmospheric oxidants. [ozone concentration and combustion product aspects in spacecraft design

    NASA Technical Reports Server (NTRS)

    Daniels, G. E.

    1973-01-01

    The ingredients which cause the air pollution are a mixture of oxides of organic matter (mostly nitrogen oxides and hydrocarbons) and ozone. Ozone, although considered one of the rare atmospheric gases, needs consideration in spacecraft design because of its chemical reaction (oxidation) with organic materials, especially rubber, which becomes hard and brittle under tension in a few minutes time. At the earth surface, a maximum of 60 parts per hundred million of oxidants composed of nitrogen oxides, hydrocarbons, sulphur dioxide, sulphur trioxides, peroxides, and ozone can be expected for 72 hours when smog occurs. A table representing distribution of ozone concentration with atmospheric altitude is included.

  2. OZONE PRODUCTION EFFICIENCY AND NOX DEPLETION IN AN URBAN PLUME: INTERPRETATION OF FIELD OBSERVATIONS AND IMPLICATIONS FOR EVALUATING O3-NOX-VOC SENSITIVITY

    EPA Science Inventory

    Ozone production efficiency (OPE) can be defined as the number of ozone (O3) molecules photochemically produced by a molecule of NOx (NO + NO2) before it is lost from the NOx - O3 cycle. Here, we consider observational and modeling techniques to evaluate various operational defi...

  3. EFFECT OF RAPID SHALLOW BREATHING ON THE DISTRIBUTION OF 18-O-LABELED OZONE REACTION PRODUCT IN THE RESPIRATORY TRACT OF THE RAT

    EPA Science Inventory

    We examined the effect of breathing pattern on ozone reaction product content within the respiratory tract. Thirty-four anesthetized, maleWistar rats were exposed to oxygen-18 (18O)-labeled ozone at 1.0 ppm for 2 h using a dual-chamber, negative-pressure ventilation system. Fre...

  4. The unique OMI HCHO/NO 2 feature during the 2008 Beijing Olympics: Implications for ozone production sensitivity

    NASA Astrophysics Data System (ADS)

    Witte, J. C.; Duncan, B. N.; Douglass, A. R.; Kurosu, T. P.; Chance, K.; Retscher, C.

    2011-06-01

    In preparation of the Beijing Summer Olympic and Paralympics Games, strict emission control measures (ECMs) were imposed between July and September 2008 on motor vehicle traffic and industrial emissions to improve air quality. We estimated changes in the chemical sensitivity of ozone production to these ECMs using Ozone Monitoring Instrument (OMI) column measurements of formaldehyde (HCHO) and nitrogen dioxide (NO 2), where their ratio serves as a proxy for the sensitivity. During the ECMs, OMI NO 2 significantly decreased, subsequently increasing the HCHO/NO 2. For the first half of the ECM time period, the ratios maintained values greater than two indicating that ozone production became primarily NO x-limited. In contrast, ozone production was predominantly volatile organic compound (VOC)-limited or mixed VOC-NO x-limited during the same period in the preceding three years. After the ECMs were lifted, NO 2 and HCHO/NO 2 returned to their previous values. The 2005-2008 OMI record shows that this transition to a predominantly NO x-limited regime during the ECMs was unique. Meteorological factors likely explain the variability in HCHO/NO 2, particularly the transition to a mixed NO x-VOC-limitation in mid-August during the Olympics, where ozone production became sensitive to both NO x and VOCs until the end of the ECMs. The mixed VOC-NO x-limited regime observed during the Paralympics is also unique because previous years show that Beijing in September is predominantly VOC-limited. Beijing's large-scale tree-planting program was expected to increase levels of biogenic VOCs, but this is not supported by OMI HCHO data. However, MODIS vegetation indices show a small increase in vegetation cover from 2003 leading up to the Games in 2008. After the Games, however, there was a downturn in the indices (2009 and 2010) to levels similar to 2006.

  5. Chemical composition of gas-phase organic carbon emissions from motor vehicles and implications for ozone production.

    PubMed

    Gentner, Drew R; Worton, David R; Isaacman, Gabriel; Davis, Laura C; Dallmann, Timothy R; Wood, Ezra C; Herndon, Scott C; Goldstein, Allen H; Harley, Robert A

    2013-10-15

    Motor vehicles are major sources of gas-phase organic carbon, which includes volatile organic compounds (VOCs) and other compounds with lower vapor pressures. These emissions react in the atmosphere, leading to the formation of ozone and secondary organic aerosol (SOA). With more chemical detail than previous studies, we report emission factors for over 230 compounds from gasoline and diesel vehicles via two methods. First we use speciated measurements of exhaust emissions from on-road vehicles in summer 2010. Second, we use a fuel composition-based approach to quantify uncombusted fuel components in exhaust using the emission factor for total uncombusted fuel in exhaust together with detailed chemical characterization of liquid fuel samples. There is good agreement between the two methods except for products of incomplete combustion, which are not present in uncombusted fuels and comprise 32 ± 2% of gasoline exhaust and 26 ± 1% of diesel exhaust by mass. We calculate and compare ozone production potentials of diesel exhaust, gasoline exhaust, and nontailpipe gasoline emissions. Per mass emitted, the gas-phase organic compounds in gasoline exhaust have the largest potential impact on ozone production with over half of the ozone formation due to products of incomplete combustion (e.g., alkenes and oxygenated VOCs). When combined with data on gasoline and diesel fuel sales in the U.S., these results indicate that gasoline sources are responsible for 69-96% of emissions and 79-97% of the ozone formation potential from gas-phase organic carbon emitted by motor vehicles. PMID:24011064

  6. Filamentous fungi for production of food additives and processing aids.

    PubMed

    Archer, David B; Connerton, Ian F; MacKenzie, Donald A

    2008-01-01

    Filamentous fungi are metabolically versatile organisms with a very wide distribution in nature. They exist in association with other species, e.g. as lichens or mycorrhiza, as pathogens of animals and plants or as free-living species. Many are regarded as nature's primary degraders because they secrete a wide variety of hydrolytic enzymes that degrade waste organic materials. Many species produce secondary metabolites such as polyketides or peptides and an increasing range of fungal species is exploited commercially as sources of enzymes and metabolites for food or pharmaceutical applications. The recent availability of fungal genome sequences has provided a major opportunity to explore and further exploit fungi as sources of enzymes and metabolites. In this review chapter we focus on the use of fungi in the production of food additives but take a largely pre-genomic, albeit a mainly molecular, view of the topic. PMID:18253709

  7. Giardia duodenalis: effects of an ozonized sunflower oil product (Oleozon) on in vitro trophozoites.

    PubMed

    Hernández, Frank; Hernández, Damian; Zamora, Zullyt; Díaz, Maritza; Ancheta, Odelsa; Rodriguez, Sandra; Torres, Dinorah

    2009-03-01

    The ozonized sunflower oil product (Oleozon) was investigated to explore its cytotoxic activity on Giardia duodenalis in vitro cultivated trophozites. Oleozon produced inactivation of Giardia trophozoites in a dose- and cell density-dependent manner. Thirty microliter of Oleozon with peroxide index value of 500 equivalent-mmol of activated oxygen per kilogram were used to achieve a 100% inhibition (<-4.00 log unit) of trophozoites from an initial inoculum of 15x10(4) cells. This potent effect was confirmed by transmission electron microscopy where morphological deterioration of superficial structures mainly in the ventral disc, and formation of a great number of micro vesicles in the cytoplasm were found. We concluded that a direct chemical-oxidation attack by the active substances from Oleozon is one of the causes of the parasitocidal effect of this product. We suggest that the dose and cell density-dependent effect must be taken into account when prescription of this product for giardiasis treatment in humans. PMID:19010325

  8. Enhancing ethanol production from thermophilic and mesophilic solid digestate using ozone combined with aqueous ammonia pretreatment.

    PubMed

    Wang, Dianlong; Xi, Jiang; Ai, Ping; Yu, Liang; Zhai, Hong; Yan, Shuiping; Zhang, Yanlin

    2016-05-01

    Pretreatment with ozone combined with aqueous ammonia was used to recover residual organic carbon from recalcitrant solid digestate for ethanol production after anaerobic digestion (AD) of rice straw. Methane yield of AD at mesophilic and thermophilic conditions, and ethanol production of solid digestate were investigated. The results showed that the methane yield at thermophilic temperature was 72.2% higher than that at mesophilic temperature under the same conditions of 24days and 17% solid concentration. And also the ethanol production efficiency of solid digestate after thermophilic process was 24.3% higher than that of solid digestate after mesophilic process. In this study, the optimal conditions for integrated methane and ethanol processes were determined as 55°C, 17% solid concentration and 24days. 58.6% of glucose conversion, 142.8g/kg of methane yield and 65.2g/kg of ethanol yield were achieved, and the highest net energy balance was calculated as 6416kJ/kg. PMID:26868156

  9. Understanding in-situ ozone production in the summertime through radical observations and modelling studies during the Clean air for London project

    NASA Astrophysics Data System (ADS)

    Whalley, Lisa; Stone, Daniel; Sharp, Thomas; Garraway, Shani; Bannan, Thomas; Percival, Carl; Hopkins, James; Holmes, Rachel; Hamilton, Jacqui; Lee, James; Laufs, Sebastian; Kleffmann, Jörg; Heard, Dwayne

    2014-05-01

    -oxidation products was considered in addition to the measured primary OH reactants. Carbonyl species such as formaldehyde, acetaldehyde and acetone have been identified as the VOC class dominating organic OH reactivity. As such, together with the direct radical source contribution by photolysis, these species dominate local ozone production in London. Modelling studies comparing the observed carbonyl concentrations with model predictions suggest that over 50% of the total concentration may be directly emitted and, hence, London's in-situ chemistry may be considered to contribute significantly to the ozone levels observed.

  10. Surface ozone in the urban area of Manaus, Amazonas, Brazil

    NASA Astrophysics Data System (ADS)

    Souza, R. A. F. D.; Costa, P. S.; Silva, C.; Godoi, R. M.; Martin, S. T.; Tota, J.; Barbosa, H. M.; Pauliquevis, T.; Ferreira De Brito, J.; Artaxo, P.; Manzi, A. O.; Wolf, S. A.; Cirino, G. G.

    2014-12-01

    When nitrogen oxides from vehicle and industrial emissions mix with volatile organic compounds from trees and plants with exposure to sunlight, a chemical reaction occurs contributing to ground-level ozone pollution. The preliminary results of the surface ozone study in urban area of Manaus, Amazonas State, Brazil, are presented for the first intensive operating period (IOP1) of the GoAmazon experiment (February/March 2014). Photochemical ozone production was found to be a regular process, with an afternoon maximum of the ozone mixing ratio of lower than 20 ppbv for cloudy days or clear sky weather. Typical ozone concentrations at mid-day were low (about 10 ppb). On the other hand, several high-value ozone episodes with surface ozone mixing ratios up to three times larger were registered during the dry season of 2013 (September/October). At the beginning of the wet season, the ozone concentration in Manaus decreased significantly, but diurnal variations can be found during the days with rainfall and other fast changes of meteorological conditions. Possible explanations of the nature of pulsations are discussed. Photochemical ozone production by local urban plumes of Manaus is named as a first possible source of the ozone concentration and biomass burning or power plant emissions are suggested as an alternative or an additional source.

  11. Additive manufacturing techniques for the production of tissue engineering constructs.

    PubMed

    Mota, Carlos; Puppi, Dario; Chiellini, Federica; Chiellini, Emo

    2015-03-01

    'Additive manufacturing' (AM) refers to a class of manufacturing processes based on the building of a solid object from three-dimensional (3D) model data by joining materials, usually layer upon layer. Among the vast array of techniques developed for the production of tissue-engineering (TE) scaffolds, AM techniques are gaining great interest for their suitability in achieving complex shapes and microstructures with a high degree of automation, good accuracy and reproducibility. In addition, the possibility of rapidly producing tissue-engineered constructs meeting patient's specific requirements, in terms of tissue defect size and geometry as well as autologous biological features, makes them a powerful way of enhancing clinical routine procedures. This paper gives an extensive overview of different AM techniques classes (i.e. stereolithography, selective laser sintering, 3D printing, melt-extrusion-based techniques, solution/slurry extrusion-based techniques, and tissue and organ printing) employed for the development of tissue-engineered constructs made of different materials (i.e. polymeric, ceramic and composite, alone or in combination with bioactive agents), by highlighting their principles and technological solutions. PMID:23172792

  12. Reactive uptake of ozone by proxies for organic aerosols: Surface-bound and gas-phase products

    NASA Astrophysics Data System (ADS)

    Thomas, Elan R.; Frost, Gregory J.; Rudich, Yinon

    2001-02-01

    Gas-phase and surface-bound products were determined for the reaction of ozone with self assembled monolayers of alkanes and terminal alkenes serving as proxies for atmospheric organic aerosols. The organic surfaces were characterized using infrared (IR) spectroscopy (direct absorption and attenuated total reflection) as well as contact angle measurements with water before and after the reaction with ozone. The contact angle of the organic surfaces was reduced by ˜20° owing to the reaction. Following the reaction, IR absorption due to the presence of carbonyls and carboxylic acids was observed on the surface. Gas-phase products were determined using infrared spectroscopy immediately above the reaction surface. Under dry conditions, gas-phase formaldehyde yields of 0.5±0.1 for organic monolayers of allyltrichlorosilane (C3=) and octenyltrichlorosilane (C8=) terminal alkenes were observed, in good agreement with the yields observed for gas phase ozonolysis of terminal alkenes. Surfaces of n-octane (C8) as well as processed alkene surfaces were nonreactive toward ozone. The reaction mechanism of ozone with the surface alkenes is discussed. Finally, the possible implications for the chemistry of organic aerosols are discussed and studied using a box model and realistic atmospheric scenarios.

  13. Diagnostic Evaluation of Ozone Production and Horizontal Transport in a Regional Photochemical Air Quality Modeling System

    EPA Science Inventory

    A diagnostic model evaluation effort has been performed to focus on photochemical ozone formation and the horizontal transport process since they strongly impact the temporal evolution and spatial distribution of ozone (O3) within the lower troposphere. Results from th...

  14. OZONE PRODUCTION FROM IRRADIATION OF ACETYLENE/CHLORINE MIXTURES IN AIR

    EPA Science Inventory

    The reaction of chlorine radicals with acetylene in air in the absence of oxides of nitrogen result In the formation of ozone. o ozone is observed when chlorine radicals react with methylacetylene or ethylacetylene under similar conditions. ormyl chloride is observed in all syste...

  15. EVALUATION OF OZONE EXPOSURE INDICES FOR RELATING EXPOSURE TO PLANT PRODUCTION AND FOR ESTIMATING AGRICULTURAL LOSSES

    EPA Science Inventory

    The objective of the report is: (1) to compare alternative ozone exposure indices that relate well to plant response and are useful in developing future standards for ozone; (2) to estimate standard errors and confidence intervals of regression coefficients and exposure levels of...

  16. The origin of ozone

    NASA Astrophysics Data System (ADS)

    Grewe, V.

    2006-05-01

    Highest atmospheric ozone production rates can be found at around 30 km in the tropical stratosphere, leading to ozone mixing ratios of about 10 ppmv. Those stratospheric air masses are then transported to extra-tropical latitudes via the Brewer-Dobson circulation. This is considered the main mechanism to generate mid- and high latitude ozone. By applying the climate-chemistry models E39/C and MAECHAM4/CHEM, this view is investigated in more detail. The origin of ozone in the troposphere and stratosphere is analysed, by incorporating a diagnostics ("marked ozone origin tracers") into the models, which allows to identify the origin of ozone. In most regions the simulated local ozone concentration is dominated by local ozone production, i.e. less than 50% of the ozone at higher latitudes of the stratosphere is produced in the tropics, which conflicts with the idea that the tropics are the global source for stratospheric ozone. Although episodic stratospheric intrusions occur basically everywhere, the main ozone stratosphere-to-troposphere exchange is connected to exchange processes at the sub-tropical jet-stream. The simulated tropospheric influx of ozone amounts to 420 Tg per year, and originates in the Northern Hemisphere from the extra-tropical stratosphere, whereas in the Southern Hemisphere a re-circulation of tropical tropospheric ozone contributes most to the influx of ozone into the troposphere. In the model E39/C, the upper troposphere of both hemispheres is clearly dominated by tropical tropospheric ozone (40%-50%) except for northern summer hemisphere, where the tropospheric contribution (from the tropics as well as from the Northern Hemisphere) does not exceed 20%.

  17. Atmospheric OH reactivity in central London: observations, model predictions and estimates of in situ ozone production

    NASA Astrophysics Data System (ADS)

    Whalley, Lisa K.; Stone, Daniel; Bandy, Brian; Dunmore, Rachel; Hamilton, Jacqueline F.; Hopkins, James; Lee, James D.; Lewis, Alastair C.; Heard, Dwayne E.

    2016-02-01

    9) (particularly α-pinene and limonene) and model-generated intermediates increases the modelled OH concentrations by 41 %, and the magnitude of in situ ozone production calculated from the production of RO2 was significantly lower (60 %). This work highlights that any future ozone abatement strategies should consider the role that biogenic emissions play alongside anthropogenic emissions in influencing London's air quality.

  18. Atmospheric OH reactivity in central London: observations, model predictions and estimates of in situ ozone production

    NASA Astrophysics Data System (ADS)

    Whalley, L. K.; Stone, D.; Bandy, B.; Dunmore, R.; Hamilton, J. F.; Hopkins, J.; Lee, J. D.; Lewis, A. C.; Heard, D. E.

    2015-11-01

    -generated intermediates worsened the agreement between modelled and observed OH concentrations (by 41 %) and the magnitude of in situ ozone production calculated from the production of RO2 was significantly lower (60 %). This work highlights that any future ozone abatement strategies should consider the role that biogenic emissions play alongside anthropogenic emissions in influencing London's air quality.

  19. Development of Ozone Technology Rice Storage Systems (OTRISS) for Quality Improvement of Rice Production

    NASA Astrophysics Data System (ADS)

    Nur, M.; Kusdiyantini, E.; Wuryanti, W.; Winarni, T. A.; Widyanto, S. A.; Muharam, H.

    2015-06-01

    This research has been carried out by using ozone to address the rapidly declining quality of rice in storage. In the first year, research has focused on the rice storage with ozone technology for small capacity (e.g., household) and the medium capacity (e.g., dormitories, hospitals). Ozone was produced by an ozone generator with Dielectric Barrier Discharge Plasma (DBDP). Ozone technology rice storage system (OTRISS) is using ozone charateristic which is a strong oxidizer. Ozone have a short endurance of existence and then decompose, as a result produce oxygen and radicals of oxygen. These characteristics could kill microorganisms and pests, reduce air humidity and enrich oxygen. All components used in SPBTO assembled using raw materials available in the big cities in Indonesia. Provider of high voltage (High Voltage Power Supply, 40-70 kV, 23 KH, AC) is one of components that have been assembled and tested. Ozone generator is assembled with 7 reactors of Dielectric Barrier Discharge Plasma (DBDP). Rice container that have been prepared for OTRISS have adjusted so can be integrated with generator, power supply and blower to blow air. OTRISS with a capacity of 75 kg and 100 kg have been made and tested. The ability of ozone to eliminate bacteria and fungi have been tested and resulted in a decrease of microorganisms at 3 log CFU/g. Testing in food chemistry showed that ozone treatment of rice had not changed the chemical content that still meet the standard of chemical content and nutritional applicable to ISO standard milled rice. The results of this study are very likely to be used as an alternative to rice storage systems in warehouse. Test and scale-up is being carried out in a mini warehouse whose condition is mimicked to rice in National Rice Storage of Indonesia (Bulog) to ensure quality. Next adaptations would be installed in the rice storage system in the Bulog.

  20. A multi-sites analysis on the ozone effects on Gross Primary Production of European forests.

    PubMed

    Proietti, C; Anav, A; De Marco, A; Sicard, P; Vitale, M

    2016-06-15

    Ozone (O3) is both a greenhouse gas and a secondary air pollutant causing adverse impacts on forests ecosystems at different scales, from cellular to ecosystem level. Specifically, the phytotoxic nature of O3 can impair CO2 assimilation that, in turn affects forest productivity. This study aims to evaluate the effects of tropospheric O3 on Gross Primary Production (GPP) at 37 European forest sites during the time period 2000-2010. Due to the lack of carbon assimilation data at O3 monitoring stations (and vice-versa) this study makes a first attempt to combine high resolution MODIS Gross Primary Production (GPP) estimates and O3 measurement data. Partial Correlations, Anomalies Analysis and the Random Forests Analysis (RFA) were used to quantify the effects of tropospheric O3 concentration and its uptake on GPP and to evaluate the most important factors affecting inter-annual GPP changes. Our results showed, along a North-West/South-East European transect, a negative impact of O3 on GPP ranging from 0.4% to 30%, although a key role of meteorological parameters respect to pollutant variables in affecting GPP was found. In particular, meteorological parameters, namely air temperature (T), soil water content (SWC) and relative humidity (RH) are the most important predictors at 81% of test sites. Moreover, it is interesting to highlight a key role of SWC in the Mediterranean areas (Spanish, Italian and French test sites) confirming that, soil moisture and soil water availability affect vegetation growth and photosynthesis especially in arid or semi-arid ecosystems such as the Mediterranean climate regions. Considering the pivotal role of GPP in the global carbon balance and the O3 ability to reduce primary productivity of the forests, this study can help in assessing the O3 impacts on ecosystem services, including wood production and carbon sequestration. PMID:26971205

  1. Methods of cracking a crude product to produce additional crude products

    SciTech Connect

    Mo, Weijian; Roes, Augustinus Wilhelmus Maria; Nair, Vijay

    2009-09-08

    A method for producing a crude product is disclosed. Formation fluid is produced from a subsurface in situ heat treatment process. The formation fluid is separated to produce a liquid stream and a first gas stream. The first gas stream includes olefins. The liquid stream is fractionated to produce one or more crude products. At least one of the crude products has a boiling range distribution from 38.degree. C. and 343.degree. C. as determined by ASTM Method D5307. The crude product having the boiling range distribution from 38.degree. C. and 343.degree. C. is catalytically cracked to produce one or more additional crude products. At least one of the additional crude products is a second gas stream. The second gas stream has a boiling point of at most 38.degree. C. at 0.101 MPa.

  2. Products of ozonized arachidonic acid potentiate the formation of DNA single strand breaks in cultured human lung cells

    SciTech Connect

    Kozumbo, W.J.; Hanley, N.M.; Agarwal, S.

    1996-12-31

    In this study we examined the potential for environmental levels of ozone (O{sub 3}) to degrade arachidonic acid (AA), a polyunsaturated fatty acid abundantly present in the lung, into products that can produce DNA single strand breaks (ssb) in cultured human lung cells. Human lung fibroblasts were incubated with 60 {mu}M AA that had been previously exposed to an degraded by 0.4 ppm O{sub 3} (1 hr). Incubation of the cells with O{sub 3}-exposed AA (but not with vehicle alone) for 1 hr at 4{degrees}C and 37{degrees}C produced 555 and 245 rad-equivalents of DNA ssb, respectively, as determined by the DNA alkaline elution technique. These breaks were completely eliminated when the ozonized AA solution was incubated with catalase prior to cell treatment, indicating that H{sub 2}O{sub 2} was solely responsible for damaging DNA. Superoxide dismutase, bovine serum albumin, or heat-inactivated catalase showed little, if any, inhibitory activity. The H{sub 2}O{sub 2} content for only about 40% of the observed breaks. Potentiation of the H{sub 2}O{sub 2}-induced DNA ssb persisted after removal of the carbonyl substances by chromatographic procedures, suggesting that the non-carbonyl component of ozonized AA was the responsible component for inducing augmentation of the observed increases in DNA ssb. Ozonized AA also induced DNA ssb in cultures of the human bronchial epithelial cell line BEAS-2B. Again, these breaks were shown to exceed levels that could be attributed to the presence of H{sub 2}O{sub 2} alone. These results indicate that products of ozonized AA can interact to potentiate DNA ssb in human lung cells. 42 refs., 6 figs., 3 tabs.

  3. Ozone and the stratosphere

    NASA Technical Reports Server (NTRS)

    Shimazaki, Tatsuo

    1987-01-01

    It is shown that the stratospheric ozone is effective in absorbing almost all radiation below 300 nm at heights below 300 km. The distribution of global ozone in the troposphere and the lower stratosphere, and the latitudinal variations of the total ozone column over four seasons are considered. The theory of the ozone layer production is discussed together with catalytic reactions for ozone loss and the mechanisms of ozone transport. Special attention is given to the anthropogenic perturbations, such as SST exhaust gases and freon gas from aerosol cans and refrigerators, that may cause an extensive destruction of the stratospheric ozone layer and thus have a profound impact on the world climate and on life.

  4. The Influence of Photolysis Rate Constants in Ozone Production for the Paso del Norte Region

    NASA Astrophysics Data System (ADS)

    Becerra, Fernando; Fitzgerald, Rosa

    2012-03-01

    In this research work we are focusing on understanding the relationship between photolysis rates and the photochemical ozone changes observed in the Paso del Norte region. The city of El Paso, Texas together with Ciudad Juarez, Mexico, forms the largest contiguous bi-national metropolitan area. This region suffers year-round ozone pollution events, and a better understanding is needed to mitigate them. Previous studies have found that ambient ozone concentrations tend to be higher on weekends rather than on weekdays, this phenomenon being referred to, as the ``weekend effect.'' If the ozone standard is exceeded more frequently on weekends, then this phenomenon must be considered in the design of ozone control strategies. In this work we investigate some of the most representative weekend ozone episodes at El Paso, TX, during the years 2009, 2010 and 2011 using the ozone photolysis rates. In this research the TUV radiative-transfer model is used to calculate the local photolysis rates and a UV MFRSR instrument is used to obtain experimental parameters. Seasonal variations and the weekday-weekend effect is studied. The results of this research will help to understand the underlying behavior of the photolysis rate constants when different atmospheric conditions are present.

  5. Impacts of the production and consumption of biofuels on stratospheric ozone

    NASA Astrophysics Data System (ADS)

    Revell, Laura E.; Bodeker, Greg E.; Huck, Petra E.; Williamson, Bryce E.

    2012-05-01

    Biofuels are becoming increasingly popular sources of renewable energy as economic pressures and environmental consequences encourage the use of alternatives to fossil fuels. However, growing crops destined for use as biofuels incurs large N2O emissions associated with the use of nitrogen-based fertilizers. Besides being a greenhouse gas, N2O is also the primary source of stratospheric NOx (NO + NO2) which leads to stratospheric ozone depletion. In this paper, the potential effects on the ozone layer of a large-scale shift away from fossil fuel use to biofuels consumption over the 21st century are examined. Under such a scenario, global-mean column ozone decreases by 2.6 DU between 2010 and 2100 in contrast to a 0.7 DU decrease under a control simulation (the IPCC SRES B1 scenario for greenhouse gases) and a 9.1 DU increase under the more commonly used SRES A1B scenario. Two factors cause the decrease in ozone in the biofuels simulation: 1) large N2O emissions lead to faster rates of the ozone-depleting NOx cycles and; 2) reduced CO2 emissions (due to less fossil fuel burning) lead to relatively less stratospheric cooling over the 21st century, which decreases ozone abundances. Reducing CO2 emissions while neglecting to reduce N2O emissions could therefore be damaging to the ozone layer.

  6. Effect of vibrationally excited oxygen on ozone production in the stratosphere

    SciTech Connect

    Patten, K.O. Jr.; Connell, P.S.; Kinnison, D.E.; Wuebbles, D.J.; Slanger, T.G.; Froidevaux, L.

    1994-01-20

    Photolysis of vibrationally excited oxygen produced by ultraviolet photolysis of ozone in the upper stratosphere is incorporated into the Lawrence Livermore National Laboratory two-dimensional zonally averaged chemical-radiative-transport model of the troposphere and stratosphere. The importance of this potential contributor of odd oxygen to the concentration of ozone is evaluated based on recent information on vibrational distributions of excited oxygen and on preliminary studies of energy transfer from the excited oxygen. When energy transfer rate constants similar to those of Toumi et al. (1991) are assumed, increases in model ozone concentrations of up to 4.0% in the upper stratosphere are found, and the model ozone concentrations are found to agree slightly better with measurements, including recent data from the Upper Atmosphere Research Satellite. However, the ozone increase is only 0.3% when the larger energy transfer rate constants indicated by recent experimental work are applied to the model. An ozone increase of 1% at 50 km requires energy transfer rate constants one-twentieth those of the preliminary observations. As a result, vibrationally excited oxygen processes probably do not contribute enough ozone to be significant in models of the upper stratosphere. 41 refs., 10 figs., 3 tabs.

  7. Reactive Nitrogen, Ozone and Ozone Production in the Arctic Troposphere and the Impact of Stratosphere-Troposphere Exchange

    NASA Technical Reports Server (NTRS)

    Liang, Q.; Rodriquez, J. M.; Douglass, A. R.; Crawford, J. H.; Apel, E.; Bian, H.; Blake, D. R.; Brune, W.; Chin, M.; Colarco, P. R.; daSilva, A.; Diskin, G. S.; Duncan, B. N.; Huey, L. C.; Knapp, D. J.; Montzka, D. D.; Nielsen, J. E.; Olson, J. R.; Pawson, S.; Weinheimer, A. J.

    2011-01-01

    We analyze the aircraft observations obtained during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellite (ARCTAS) mission together with the GEOS-5 CO simulation to examine O3 and NOy in the Arctic and sub-Arctic region and their source attribution. Using a number of marker tracers and their probability density distributions, we distinguish various air masses from the background troposphere and examine their contribution to NOx, O3, and O3 production in the Arctic troposphere. The background Arctic troposphere has mean O3 of approximately 60 ppbv and NOx of approximately 25 pptv throughout spring and summer with CO decreases from approximately 145 ppbv in spring to approximately 100 ppbv in summer. These observed CO, NOx and O3 mixing ratios are not notably different from the values measured during the 1988 ABLE-3A and the 2002 TOPSE field campaigns despite the significant changes in the past two decades in processes that could have changed the Arctic tropospheric composition. Air masses associated with stratosphere-troposphere exchange are present throughout the mid and upper troposphere during spring and summer. These air masses with mean O3 concentration of 140-160 ppbv are the most important direct sources of O3 in the Arctic troposphere. In addition, air of stratospheric origin is the only notable driver of net O3 formation in the Arctic due to its sustainable high NOx (75 pptv in spring and 110 pptv in summer) and NOy (approximately 800 pptv in spring and approximately 1100 pptv in summer) levels. The ARCTAS measurements present observational evidence suggesting significant conversion of nitrogen from HNO3 to NOx and then to PAN (a net formation of approximately 120 pptv PAN) in summer when air of stratospheric origin is mixed with tropospheric background during stratosphere-to-troposphere transport. These findings imply that an adequate representation of stratospheric O3 and NOy input are essential in accurately simulating O3

  8. Search for additional muons in hadronic production of Jψ particles

    NASA Astrophysics Data System (ADS)

    Anderson, K. J.; Coleman, R. N.; Karhi, K. P.; Newman, C. B.; Pilcher, J. E.; Rosenberg, E. I.; Thaler, J. J.; Hogan, G. E.; McDonald, K. T.; Sanders, G. H.; Smith, A. J. S.

    1980-06-01

    A sample of Jψ-->μ+μ- decays produced by a 225-GeV/c π- beam on nuclear targets has been analyzed for extra muons. Muons observed in coincidence with Jψ production could indicate either the production of charmed particles or the production of pairs of Jψ particles. We find 90% confidence limits of σ-JDDσJ<0.016 for associated charm production and σJJσJ<0.005 for the production of Jψ pairs.

  9. Near real-time global profile and total amounts of ozone using S-NPP CrIS and OMPS sensor products

    NASA Astrophysics Data System (ADS)

    Niu, J.; Flynn, L. E.; Kondragunta, S.; Kapoor, V.; Beck, T.; Beach, E.; Zhao, Q.

    2013-12-01

    Abstract An algorithm to create combined UV and IR total ozone maps by using CrIS and OMPS ozone environmental data records (EDRs) (Total Ozone Analysis from CrIS and OMPS - TACO) has been prepared. This product will replace the existing one made by using HIRS and SBUV/2 data products (Total Ozone Analysis from SBUV/2 and TOVS - TOAST) when the new sensor products graduate from their current provisional maturity to the validated versions. The most significant improvement of this algorithm is that the IR sensor, CrIS, provides ozone profiles instead of just a total ozone amount, which the former HIRS sensor provided. This will allow the new algorithm to provide not only the objective analysis on global total ozone amount but also the global ozone profiles. The first steps in the algorithm are to project ozone parameters such as profile and total amount with a geographic coordinate onto a stereographic coordinate map, transform the irregular spaced data into a regularly arranged grid, compute estimates for missing data in the grid, remove the data in errors, and smooth out noises. There are different versions of CrIS and OMPS EDR data available. The CrIS NUCAPS data released by NDE and the IMOPO OMPS/NP version 6 released by IDPS were selected for the main sources for this study. A pressure level at 0.03125 atm was selected as the concatenating pressure level of the two sensors. TACO Ozone profiles above this height were from a combination of OMPS/NP and or only SBUV/2, those below it, were from CrIS. One day analysis on June 8, 2013 has been compared with those in the current TOAST and total ozone maps from EOS OMI. The zonal mean of TACO total amount demonstrates lower values in northern high latitude region and higher value in southern high latitude region relative to the former TOAST results. But these changes in TACO are found to be more consistent with the OMI level 3 total ozone amount. There is a known yet to be corrected stray light problem in the current

  10. Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests.

    PubMed

    Talhelm, Alan F; Pregitzer, Kurt S; Kubiske, Mark E; Zak, Donald R; Campany, Courtney E; Burton, Andrew J; Dickson, Richard E; Hendrey, George R; Isebrands, J G; Lewin, Keith F; Nagy, John; Karnosky, David F

    2014-08-01

    Three young northern temperate forest communities in the north-central United States were exposed to factorial combinations of elevated carbon dioxide (CO2 ) and tropospheric ozone (O3 ) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment that enabled us to estimate ecosystem carbon (C) content and cumulative net primary productivity (NPP). Elevated CO2 enhanced ecosystem C content by 11%, whereas elevated O3 decreased ecosystem C content by 9%. There was little variation in treatment effects on C content across communities and no meaningful interactions between CO2 and O3 . Treatment effects on ecosystem C content resulted primarily from changes in the near-surface mineral soil and tree C, particularly differences in woody tissues. Excluding the mineral soil, cumulative NPP was a strong predictor of ecosystem C content (r(2) = 0.96). Elevated CO2 enhanced cumulative NPP by 39%, a consequence of a 28% increase in canopy nitrogen (N) content (g N m(-2) ) and a 28% increase in N productivity (NPP/canopy N). In contrast, elevated O3 lowered NPP by 10% because of a 21% decrease in canopy N, but did not impact N productivity. Consequently, as the marginal impact of canopy N on NPP (∆NPP/∆N) decreased through time with further canopy development, the O3 effect on NPP dissipated. Within the mineral soil, there was less C in the top 0.1 m of soil under elevated O3 and less soil C from 0.1 to 0.2 m in depth under elevated CO2 . Overall, these results suggest that elevated CO2 may create a sustained increase in NPP, whereas the long-term effect of elevated O3 on NPP will be smaller than expected. However, changes in soil C are not well-understood and limit our ability to predict changes in ecosystem C content. PMID:24604779

  11. Hydrocarbon Observations and Ozone Production Rates in Western Houston During the Texas 2000 Air Quality Study

    SciTech Connect

    Berkowitz, Carl M.; Spicer, Chet W.; Doskey, Paul V.

    2005-06-01

    Measurements of total non-methane hydrocarbon in whole air canisters collected from the top of a skyscraper on the western edge of Houston, Texas are summarized with an emphasis on samples collected during the passage of plumes of O{sub 3} and the associated rapid increase in the mixing ratio of this species. The back-trajectories associated with these events showed a pronounced deceleration of air parcels over central and western Houston and were not necessarily associated with direct passage over the petrochemical plants located in the heavily industrialized eastern part of Houston. As a result of the time these air parcels spent over the central and western parts of Houston, their VOC mix and associated chemical production rates were expected to differ from similar observations made over eastern Houston from aircraft sampling at low altitudes. Although periods of high O{sub 3} in the western part of the city were closely associated with light alkenes, these same observations show isoprene to make a significant contribution to the total VOC reactivity in the early afternoon (the start of peak photochemical activity) in contrast to observations made east of our sampling site that found the reactivity to be dominated by anthropogenic species. By initializing a 0-dimensional chemical kinetic model with observations made at the Williams Tower, we find that the ozone production efficiency scaled linearly to the ratio of total hydrocarbons and NO{sub x}, with an average OPE of 7.2, ranging from 2.3 to 16.9; these values are smaller than those reported in eastern Houston, suggesting a strong gradient in photochemical productivity across the city.

  12. Photodissociation of ozone in the Hartley band: Product state and angular distributions.

    PubMed

    McBane, George C; Nguyen, Luan T; Schinke, Reinhard

    2010-10-14

    Product state properties from the photodissociation of ozone in the ultraviolet Hartley band are investigated by trajectory surface-hopping calculations. The diabatic B and R state potential energy and coupling surfaces of Schinke and McBane [J. Chem. Phys. 132, 044305 (2010)] are employed. The properties computed include rotational and vibrational distributions in both the singlet and triplet channels, the total internal energy distribution in the triplet channel, and the photodissociation anisotropy parameter β in the singlet channel. A method for computing β from trajectories computed in internal Jacobi coordinates is described. In the singlet channel, the vibrational distribution is in good agreement with the experimental results. The observed increase in β with increasing photolysis wavelength is reproduced by the calculations and is attributed to the effects of the bending potential on the B state late in the fragmentation. The computed β values are too high with respect to experiment, and the peaks j(max) of the singlet-channel rotational distributions are too low; these discrepancies are attributed to a too steep bending potential at long O-O distances. In the triplet channel, the main part of the internal energy distribution is described well by the calculations, although the detailed structures observed in the experiment are not reproduced. The experimental rotational distributions are well reproduced, although the maxima appear at slightly too high j. The triplet state product energy distributions are shown to depend largely on the distribution of hopping points onto the R state surface. A Landau-Zener model constructed as a function of the O(2) bond distance provides a good physical description of the two-state dynamics. The high internal energy O(2) products that cannot be attributed to the excitation of the Herzberg states remain unexplained. PMID:20950005

  13. 40 CFR 300.920 - Addition of products to Schedule.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... pursuant to the provisions in 40 CFR part 2, subpart B. Such information must be submitted separately from... approval of the product. To avoid possible misinterpretation or misrepresentation, any label, advertisement...) Dispersants. (1) To add a dispersant to the NCP Product Schedule, submit the technical product data...

  14. Standardizing Interfaces for External Access to Data and Processing for the NASA Ozone Product Evaluation and Test Element (PEATE)

    NASA Technical Reports Server (NTRS)

    Tilmes, Curt A.; Fleig, Albert J.

    2008-01-01

    NASA's traditional science data processing systems have focused on specific missions, and providing data access, processing and services to the funded science teams of those specific missions. Recently NASA has been modifying this stance, changing the focus from Missions to Measurements. Where a specific Mission has a discrete beginning and end, the Measurement considers long term data continuity across multiple missions. Total Column Ozone, a critical measurement of atmospheric composition, has been monitored for'decades on a series of Total Ozone Mapping Spectrometer (TOMS) instruments. Some important European missions also monitor ozone, including the Global Ozone Monitoring Experiment (GOME) and SCIAMACHY. With the U.S.IEuropean cooperative launch of the Dutch Ozone Monitoring Instrument (OMI) on NASA Aura satellite, and the GOME-2 instrumental on MetOp, the ozone monitoring record has been further extended. In conjunction with the U.S. Department of Defense (DoD) and the National Oceanic and Atmospheric Administration (NOAA), NASA is now preparing to evaluate data and algorithms for the next generation Ozone Mapping and Profiler Suite (OMPS) which will launch on the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP) in 2010. NASA is constructing the Science Data Segment (SDS) which is comprised of several elements to evaluate the various NPP data products and algorithms. The NPP SDS Ozone Product Evaluation and Test Element (PEATE) will build on the heritage of the TOMS and OM1 mission based processing systems. The overall measurement based system that will encompass these efforts is the Atmospheric Composition Processing System (ACPS). We have extended the system to include access to publically available data sets from other instruments where feasible, including non-NASA missions as appropriate. The heritage system was largely monolithic providing a very controlled processing flow from data.ingest of

  15. Ozone vegetation damage effects on gross primary productivity in the United States

    NASA Astrophysics Data System (ADS)

    Yue, X.; Unger, N.

    2014-09-01

    We apply an off-line process-based vegetation model (the Yale Interactive Terrestrial Biosphere model) to assess the impacts of ozone (O3) vegetation damage on gross primary productivity (GPP) in the United States during the past decade (1998-2007). The model's GPP simulation is evaluated at 40 sites of the North American Carbon Program (NACP) synthesis. The ecosystem-scale model version reproduces interannual variability and seasonality of GPP at most sites, especially in croplands. Inclusion of the O3 damage impact decreases biases of simulated GPP at most of the NACP sites. The simulation with the O3 damage effect reproduces 64% of the observed variance in summer GPP and 42% on the annual average. Based on a regional gridded simulation over the US, summertime average O3-free GPP is 6.1 g C m-2 day-1 (9.5 g C m-2 day-1 in the east of 95° W and 3.9 g C m-2 day-1 in the west). O3 damage decreases GPP by 4-8% on average in the eastern US and leads to significant decreases of 11-17% in east coast hot spots. Sensitivity simulations show that a 25% decrease in surface O3 concentration halves the average GPP damage to only 2-4%, suggesting the substantial co-benefits to ecosystem health that may be achieved via O3 air pollution control.

  16. IDENTIFICATION OF DRINKING WATER DISINFECTION BY-PRODUCTS FROM OZONE, CHLORINE DIOXIDE, CHLORAMINE, AND CHLORINE

    EPA Science Inventory

    Many drinking water treatment plants are currently using alternative disinfectants to treat drinking water, with ozone, chlorine dioxide, and chloramine being the most popular. However, compared to chlorine, which has been much more widely studied, there is little information abo...

  17. Singlet oxygen production from the reactions of ozone with biological molecules

    SciTech Connect

    Kanofsky, J.R.; Sima, P. )

    1991-05-15

    The reaction of ozone with a number of biological molecules was found to produce singlet oxygen in high yield. At pH 7.0, the reaction of ozone with an equimolar amount of biological molecule produced the following singlet oxygen yields (mole of singlet oxygen/mole of ozone): cysteine, 0.49 +/- 0.02; methionine, 1.13 +/- 0.11; reduced glutathione, 0.33 +/- 0.02; albumin, 1.00 +/- 0.05; uric acid, 0.64 +/- 0.09; ascorbic acid, 0.96 +/- 0.007; NADPH, 1.07 +/- 0.07; NADH, 0.95 +/- 0.01. Thus, singlet oxygen may be an important intermediate in the biochemical damage caused by ozone.

  18. Ozone-Induced Dissociation of Conjugated Lipids Reveals Significant Reaction Rate Enhancements and Characteristic Odd-Electron Product Ions

    NASA Astrophysics Data System (ADS)

    Pham, Huong T.; Maccarone, Alan T.; Campbell, J. Larry; Mitchell, Todd W.; Blanksby, Stephen J.

    2013-02-01

    Ozone-induced dissociation (OzID) is an alternative ion activation method that relies on the gas phase ion-molecule reaction between a mass-selected target ion and ozone in an ion trap mass spectrometer. Herein, we evaluated the performance of OzID for both the structural elucidation and selective detection of conjugated carbon-carbon double bond motifs within lipids. The relative reactivity trends for [M + X]+ ions (where X = Li, Na, K) formed via electrospray ionization (ESI) of conjugated versus nonconjugated fatty acid methyl esters (FAMEs) were examined using two different OzID-enabled linear ion-trap mass spectrometers. Compared with nonconjugated analogues, FAMEs derived from conjugated linoleic acids were found to react up to 200 times faster and to yield characteristic radical cations. The significantly enhanced reactivity of conjugated isomers means that OzID product ions can be observed without invoking a reaction delay in the experimental sequence (i.e., trapping of ions in the presence of ozone is not required). This possibility has been exploited to undertake neutral-loss scans on a triple quadrupole mass spectrometer targeting characteristic OzID transitions. Such analyses reveal the presence of conjugated double bonds in lipids extracted from selected foodstuffs. Finally, by benchmarking of the absolute ozone concentration inside the ion trap, second order rate constants for the gas phase reactions between unsaturated organic ions and ozone were obtained. These results demonstrate a significant influence of the adducting metal on reaction rate constants in the fashion Li > Na > K.

  19. Use of 'natural' products as alternatives to antibiotic feed additives in ruminant production.

    PubMed

    Jouany, J-P; Morgavi, D P

    2007-11-01

    The banning in 2006 of the use of antibiotics as animal growth promoters in the European Union has increased demand from producers for alternative feed additives that can be used to improve animal production. This review gives an overview of the most common non-antibiotic feed additives already being used or that could potentially be used in ruminant nutrition. Probiotics, dicarboxylic acids, enzymes and plant-derived products including saponins, tannins and essential oils are presented. The known modes of action and effects of these additives on feed digestion and more especially on rumen fermentations are described. Their utility and limitations in field conditions for modern ruminant production systems and their compliance with the current legislation are also discussed. PMID:22444918

  20. 15 CFR 1180.6 - Production of additional copies.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... (Continued) TECHNOLOGY ADMINISTRATION, DEPARTMENT OF COMMERCE TRANSFER BY FEDERAL AGENCIES OF SCIENTIFIC, TECHNICAL AND ENGINEERING INFORMATION TO THE NATIONAL TECHNICAL INFORMATION SERVICE § 1180.6 Production...

  1. 15 CFR 1180.6 - Production of additional copies.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... (Continued) TECHNOLOGY ADMINISTRATION, DEPARTMENT OF COMMERCE TRANSFER BY FEDERAL AGENCIES OF SCIENTIFIC, TECHNICAL AND ENGINEERING INFORMATION TO THE NATIONAL TECHNICAL INFORMATION SERVICE § 1180.6 Production...

  2. 15 CFR 1180.6 - Production of additional copies.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... (Continued) TECHNOLOGY ADMINISTRATION, DEPARTMENT OF COMMERCE TRANSFER BY FEDERAL AGENCIES OF SCIENTIFIC, TECHNICAL AND ENGINEERING INFORMATION TO THE NATIONAL TECHNICAL INFORMATION SERVICE § 1180.6 Production...

  3. Microstructure-controllable Laser Additive Manufacturing Process for Metal Products

    NASA Astrophysics Data System (ADS)

    Huang, Wei-Chin; Chuang, Chuan-Sheng; Lin, Ching-Chih; Wu, Chih-Hsien; Lin, De-Yau; Liu, Sung-Ho; Tseng, Wen-Peng; Horng, Ji-Bin

    Controlling the cooling rate of alloy during solidification is the most commonly used method for varying the material microstructure. However, the cooling rate of selective laser melting (SLM) production is constrained by the optimal parameter settings for a dense product. This study proposes a method for forming metal products via the SLM process with electromagnetic vibrations. The electromagnetic vibrations change the solidification process for a given set of SLM parameters, allowing the microstructure to be varied via magnetic flux density. This proposed method can be used for creating microstructure-controllable bio-implant products with complex shapes.

  4. Characterizing the impacts of vertical transport and photochemical ozone production on an exceedance area

    NASA Astrophysics Data System (ADS)

    Yates, Emma L.; Iraci, Laura T.; Austerberry, David; Pierce, R. Bradley; Roby, Matthew C.; Tadić, Jovan M.; Loewenstein, Max; Gore, Warren

    2015-05-01

    Offshore and inland vertical profiles of ozone (O3) were measured from an aircraft during 16 flights from January 2012 to January 2013 over the northern San Joaquin Valley (SJV) and over the Pacific Ocean. Analysis of in situ measurements presents an assessment of the seasonality and magnitude of net O3 production and transport within the lower troposphere above the SJV. During the high O3 season (May-October), the Dobson Unit sum of O3 in the 0-2 km above sea level (km.a.s.l.) layer above the SJV exceeds that above the offshore profile by up to 20.5%, implying net O3 production over the SJV or vertical transport from above. During extreme events (e.g. Stratosphere-to-troposphere transport) vertical features (areas of enhanced or depleted O3 or water vapor) are observed in the offshore and SJV profiles at different altitudes, demonstrating the scale of vertical mixing during transport. Correlation analysis between offshore O3 profiles and O3 surface sites in the SJV lends further support the hypothesis of vertical mixing. Correlation analysis indicates that O3 mixing ratios at surface sites in the northern and middle SJV show significant correlations to the 1.5-2 km.a.s.l. offshore altitude range. Southern SJV O3 surface sites show a shift towards maximum correlations at increased time-offsets, and O3 surface sites at elevated altitudes show significant correlations with higher offshore altitudes (2.5-4 km.a.s.l.).

  5. Ozone crisis

    SciTech Connect

    Roan, S.

    1989-01-01

    The author presents an account of the depletion of the atmosphere's ozone layer since the discovery of the phenomenon 15 years ago. The book recounts the flight to ban chlorofluorocarbons (CFC's) and describes the science, the people, and the politics involved, up to the March 1988 international treaty restricting CFC production. It surveys the media's coverage, describes the struggle for remedies, and offers a prognosis for the future.

  6. Lidar-derived Correlations Between Lower-tropospheric Column and Surface Ozone: Implications for Satellite Observations

    NASA Astrophysics Data System (ADS)

    Senff, C. J.; Langford, A. O.; Alvarez, R. J. _II, II; Kirgis, G.; Choukulkar, A.; Brewer, A.; Banta, R. M.; Weickmann, A. M.; Sandberg, S.; Olson, E.

    2015-12-01

    One of the data products that will be provided by the TEMPO satellite mission is 0-2 km ozone column concentration. To make inferences about surface air quality from this data product, the relationship between lower-tropospheric column and surface ozone concentrations and their diurnal, seasonal, and spatial variations have to be well understood. To characterize these relationships, we have used ozone profile observations obtained with NOAA's truck-based, scanning TOPAZ ozone lidar from several recent field campaigns including Discover-AQ Houston and Colorado, the Uintah Basin Wintertime Ozone Study (UBWOS), and the Las Vegas Ozone Study (LVOS). The TOPAZ lidar is ideally suited for this kind of study because it provides ozone profiles from about 15 m above ground level (AGL) up to 3 km AGL at high spatial and temporal resolution. We have used the lidar observations closest to the ground as a proxy for surface ozone and compared them to the 0-2 km AGL average column ozone concentrations measured with the lidar. Results from the Discover-AQ Colorado campaign show that in the afternoon, when the boundary layer (BL) was deep and well mixed, ozone column and surface concentrations agreed quite well. However, during the morning hours, ozone column concentrations were significantly higher than those at the surface, because ozone was depleted in a shallow surface layer due to titration and deposition, whereas ozone levels in the residual layer aloft remained moderately high. The analysis of column and surface ozone correlations using ozone lidar observations from the Discover-AQ Houston, UBWOS and LVOS campaigns is currently underway. The results from these studies will provide additional insights into the relationship between column and surface ozone, in particular their variation as a function of measurement location and season, and their dependence on BL processes such as mixed layer height evolution, land-sea breeze circulation, and terrain-induced flows.

  7. Impact of asthma, exposure period, and filters on human responses during exposures to ozone and its initiated chemistry products.

    PubMed

    Fadeyi, M O; Tham, K W; Wu, W Y

    2015-10-01

    The impact of asthma, exposure period, and filter condition downstream of the mixing box of air-conditioning system on building occupants' perceptual response, work performance, and salivary α-amylase secretion during exposures to ozone and its initiated chemistry products is studied. The experiments were conducted in a field environmental chamber (FEC) (240 m(3)) simulating an office environment. Experiments were conducted during periods when the air-handling system operated with new or used pleated panel filters at constant recirculation (7/h) and ventilation (1/h) rates. Average ozone and secondary organic aerosols (ozone-initiated chemistry products) measured during non-asthmatic and asthmatic subjects' 3-h exposures in the FEC were in the ranges approximately 20-37 ppb and approximately 1.6-3 μg/m(3), respectively. Asthmatic subjects' perceived odor intensity and sensory (eye, nose, and throat) irritation ratings were generally lower than those of non-asthmatic subjects, possibly explaining why asthmatic subjects accept perceived air quality more than non-asthmatic subjects. However, asthmatic subjects' perceived physiological-like symptom ratings (flu, chest tightness, and headache) and concentrations of secreted salivary α-amylase were generally higher than those of non-asthmatic subjects. Asthmatic subjects had significantly lower accuracy than non-asthmatic subjects in a task that required higher concentration although they had higher work speed. Filter condition did not make any significant difference for subjects' responses. PMID:25250543

  8. Optimization of Ozonation Process for the Reduction of Excess Sludge Production from Activated Sludge Process of Sago Industry Wastewater Using Central Composite Design

    PubMed Central

    Subha, B.; Muthukumar, M.

    2012-01-01

    Sago industries effluent containing large amounts of organic content produced excess sludge which is a serious problem in wastewater treatment. In this study ozonation has been employed for the reduction of excess sludge production in activated sludge process. Central composite design is used to study the effect of ozone treatment for the reduction of excess sludge production in sago effluent and to optimise the variables such as pH, ozonation time, and retention time. ANOVA showed that the coefficient determination value (R2) of VSS and COD reduction were 0.9689 and 0.8838, respectively. VSS reduction (81%) was achieved at acidic pH 6.9, 12 minutes ozonation, and retention time of 10 days. COD reduction (87%) was achieved at acidic pH 6.7, 8 minutes of ozonation time, and retention time of 6 days. Low ozonation time and high retention time influence maximum sludge reduction, whereas low ozonation time with low retention time was effective for COD reduction. PMID:22593666

  9. GC-MS(n) and LC-MS/MS couplings for the identification of degradation products resulting from the ozonation treatment of Acetochlor.

    PubMed

    Bouchonnet, Stéphane; Bourcier, Sophie; Souissi, Yasmine; Genty, Christophe; Sablier, Michel; Roche, Pascal; Boireau, Véronique; Ingrand, Valérie

    2012-04-01

    The degradation of the chloracetamide herbicide acetochlor has been studied under simulated ozonation treatment plant conditions. The degradation of acetochlor included the formation of several degradation products that were identified using GC/ion-trap mass spectrometry with EI and CI and HPLC/electrospray-QqTOF mass spectrometry. Thirteen ozonation products of acetochlor have been identified. Ozonation of the deuterated herbicide combined to MS(n) and high-resolution mass measurement allowed effective characterization of the degradation products. At the exception of one of them, the product B (2-chloro-2', ethyl-6', methyl-acetanilide), none of the identified degradation products has been already reported in the literature. Post-ozonation kinetics studies revealed that the concentrations of most degradation products evolved noticeably with time, particularly during the first hours following the ozonation treatment. This raises concerns about the fate of degradation products in the effluents of treatment plants and suggests the need for a better control on these products if their toxicity was demonstrated. PMID:22689619

  10. Ozone production efficiency of a ship-plume: ITCT 2K2 case study.

    PubMed

    Kim, Hyun S; Kim, Yong H; Han, Kyung M; Kim, Jhoon; Song, Chul H

    2016-01-01

    Ozone production efficiency (OPE) of ship plume was first evaluated in this study, based on ship-plume photochemical/dynamic model simulations and the ship-plume composition data measured during the ITCT 2K2 (Intercontinental Transport and Chemical Transformation 2002) aircraft campaign. The averaged instantaneous OPEs (OPE(i)‾) estimated via the ship-plume photochemical/dynamic modeling for the ITCT 2K2 ship-plume ranged between 4.61 and 18.92, showing that the values vary with the extent of chemical evolution (or chemical stage) of the ship plume and the stability classes of the marine boundary layer (MBL). Together with OPE(i)‾, the equivalent OPEs (OPE(e)‾) for the entire ITCT 2K2 ship-plume were also estimated. The OPE(e)‾ values varied between 9.73 (for the stable MBL) and 12.73 (for the moderately stable MBL), which agreed well with the OPE(e)‾ of 12.85 estimated based on the ITCT 2K2 ship-plume observations. It was also found that both the model-simulated and observation-based OPE(e)‾ inside the ship-plume were 0.29-0.38 times smaller than the OPE(e)‾ calculated/measured outside the ITCT 2K2 ship-plume. Such low OPEs insides the ship plume were due to the high levels of NO and non-liner ship-plume photochemistry. Possible implications of this ship-plume OPE study in the global chemistry-transport modeling are also discussed. PMID:26009472

  11. Root and shoot gas exchange respond additively to moderate ozone and methyl jasmonate without induction of ethylene: ethylene is induced at higher O3 concentrations

    PubMed Central

    Grantz, D.A.; Vu, H.-B.

    2012-01-01

    The available literature is conflicting on the potential protection of plants against ozone (O3) injury by exogenous jasmonates, including methyl jasmonate (MeJA). Protective antagonistic interactions of O3 and MeJA have been observed in some systems and purely additive effects in others. Here it is shown that chronic exposure to low to moderate O3 concentrations (4–114 ppb; 12 h mean) and to MeJA induced additive reductions in carbon assimilation (A n) and root respiration (R r), and in calculated whole plant carbon balance. Neither this chronic O3 regime nor MeJA induced emission of ethylene (ET) from the youngest fully expanded leaves. ET emission was induced by acute 3 h pulse exposure to much higher O3 concentrations (685 ppb). ET emission was further enhanced in plants treated with MeJA. Responses of growth, allocation, photosynthesis, and respiration to moderate O3 concentrations and to MeJA appear to be independent and additive, and not associated with emission of ET. These results suggest that responses of Pima cotton to environmentally relevant O3 are not mediated by signalling pathways associated with ET and MeJA, though these pathways are inducible in this species and exhibit a synergistic O3×MeJA interaction at very high O3 concentrations. PMID:22563119

  12. Photochemical production of ozone in Beijing during the 2008 Olympic Games

    NASA Astrophysics Data System (ADS)

    Chou, C. C.-K.; Tsai, C.-Y.; Chang, C.-C.; Lin, P.-H.; Liu, S. C.; Zhu, T.

    2011-09-01

    As a part of the CAREBeijing-2008 campaign, observations of O3, oxides of nitrogen (NOx and NOy), CO, and hydrocarbons (NMHCs) were carried out at the air quality observatory of the Peking University in Beijing, China during August 2008, including the period of the 29th Summer Olympic Games. The measurements were compared with those of the CAREBeijing-2006 campaign to evaluate the effectiveness of the air pollution control measures, which were conducted for improving the air quality in Beijing during the Olympics. The results indicate that significant reduction in the emissions of primary air pollutants had been achieved; the monthly averaged mixing ratios of NOx, NOy, CO, and NMHCs decreased by 42.2, 56.5, 27.8, and 49.7 %, respectively. In contrast to the primary pollutants, the averaged mixing ratio of O3 increased by 42.2 %. Nevertheless, it was revealed that the ambient levels of total oxidant (Ox = O3+NO2+1.5 NOz) and NOz were reduced by 21.3 and 77.4 %, respectively. The contradictions between O3 and Ox were further examined in two case studies. Ozone production rates of 30-70 ppbv h-1 and OPEx of ~8 mole mole-1 were observed on a clear-sky day in spite of the reduced levels of precursors. In that case, it was found that the mixing ratio of O3 increased with the increasing NO2/NO ratio, whereas the NOz mixing ratio leveled off when NO2/NO>8. Consequently, the ratio of O3 to NOz increased to above 10, indicating the shift from VOC-sensitive regime to NOx-sensitive regime. However, in the other case, it was found that the O3 production was inhibited significantly due to substantial reduction in the NMHCs. According to the observations, it was suggested that the O3 and/or Ox production rates in Beijing should have been reduced as a result of the reduction in the emissions of precursors during the Olympic period. However, the nighttime O3 levels increased due to a decline in the NO-O3 titration, and the midday O3 peak levels were elevated because of the shift in

  13. AP-42 ADDITIONS AND REVISIONS - RUBBER PRODUCTS MANUFACTURING

    EPA Science Inventory

    This project develops emission factors, etc., for the rubber products industry which are appended to AP-42. AP42 is a massive collection of material which describes processes which generate air emissions and presents emission factors and control effectiveness information. As res...

  14. Ozonated olive oils and the troubles.

    PubMed

    Uysal, Bulent

    2014-01-01

    One of the commonly used methods for ozone therapy is ozonated oils. Most prominent type of used oils is extra virgin olive oil. But still, each type of unsaturated oils may be used for ozonation. There are a lot of wrong knowledge on the internet about ozonated oils and its use as well. Just like other ozone therapy studies, also the studies about ozone oils are inadequate to avoid incorrect knowledge. Current data about ozone oil and its benefits are produced by supplier who oversees financial interests and make misinformation. Despite the rapidly increasing ozone oil sales through the internet, its quality and efficacy is still controversial. Dozens of companies and web sites may be easily found to buy ozonated oil. But, very few of these products are reliable, and contain sufficiently ozonated oil. This article aimed to introduce the troubles about ozonated oils and so to inform ozonated oil users. PMID:26401346

  15. Ozonated olive oils and the troubles

    PubMed Central

    Uysal, Bulent

    2014-01-01

    One of the commonly used methods for ozone therapy is ozonated oils. Most prominent type of used oils is extra virgin olive oil. But still, each type of unsaturated oils may be used for ozonation. There are a lot of wrong knowledge on the internet about ozonated oils and its use as well. Just like other ozone therapy studies, also the studies about ozone oils are inadequate to avoid incorrect knowledge. Current data about ozone oil and its benefits are produced by supplier who oversees financial interests and make misinformation. Despite the rapidly increasing ozone oil sales through the internet, its quality and efficacy is still controversial. Dozens of companies and web sites may be easily found to buy ozonated oil. But, very few of these products are reliable, and contain sufficiently ozonated oil. This article aimed to introduce the troubles about ozonated oils and so to inform ozonated oil users. PMID:26401346

  16. An Airborne Investigation of Boundary Layer Dynamics, Entrainment, and Ozone Photochemical Production During DISCOVER-AQ in California's Central Valley

    NASA Astrophysics Data System (ADS)

    Conley, S. A.; Post, A.; Faloona, I. C.

    2014-12-01

    During the California deployment of NASA's DISCOVER-AQ project of January/February 2013, our team flew a Mooney TLS research aircraft instrumented with an in-house wind measurement system, a UV absorption ozone instrument, temperature probe, and a Picarro methane, carbon dioxide, and water vapor analyzer. Flights were focused on the lowest 1000 m across the Central Valley axis just north of Fresno in order to characterize the wintertime atmospheric boundary layer (ABL). For seven flights we report the observed ABL growth rates, and compare these with a simple mixed layer model driven by surface heat flux estimates from the North American Regional Reanalysis data set. By enforcing a mixed layer budget closure of the observed water vapor trend and the differential across the ABL top, we derive midday entrainment velocities for the region that average 1.2 (± 0.4) cm s-1. A similar budgeting method is used for ozone to estimate wintertime photochemical production rates that ranged from 0.5 to 7.0 ppb h-1, and exhibited a strong correlation with ambient temperature (see Figure) and total ozone abundance. Finally, the gross emissions of methane for this heavily agricultural region are estimated and compared to existing inventories. These results can provide important constraints on ABL growth and entrainment to aid surface studies of aerosol composition and other trace gases that are being conducted for DISCOVER-AQ.

  17. Increasing Springtime Ozone Mixing Ratios in the Free Troposphere Over Western North America

    NASA Technical Reports Server (NTRS)

    Cooper, O. R.; Parrish, D. D.; Stohl, A.; Trainer, M.; Nedelec, P.; Thouret, V.; Cammas, J. P.; Oltmans, S. J.; Johnson, B. J.; Tarasick, D.; Leblanc, T.; McDermid, I. S.; Jaffe, D.; Gao, R.; Stith, J.; Ryerson, T.; Aikin, K.; Campos, T.; Weinheimer, A.; Avery, M. A.

    2010-01-01

    In the lowermost layer of the atmosphere - the troposphere - ozone is an important source of the hydroxyl radical, an oxidant that breaks down most pollutants and some greenhouse gases. High concentrations of tropospheric ozone are toxic, however, and have a detrimental effect on human health and ecosystem productivity1. Moreover, tropospheric ozone itself acts as an effective greenhouse gas. Much of the present tropospheric ozone burden is a consequence of anthropogenic emissions of ozone precursors resulting in widespread increases in ozone concentrations since the late 1800s. At present, east Asia has the fastest-growing ozone precursor emissions. Much of the springtime east Asian pollution is exported eastwards towards western North America. Despite evidence that the exported Asian pollution produces ozone, no previous study has found a significant increase in free tropospheric ozone concentrations above the western USA since measurements began in the late 1970s. Here we compile springtime ozone measurements from many different platforms across western North America. We show a strong increase in springtime ozone mixing ratios during 1995-2008 and we have some additional evidence that a similar rate of increase in ozone mixing ratio has occurred since 1984. We find that the rate of increase in ozone mixing ratio is greatest when measurements are more heavily influenced by direct transport from Asia. Our result agrees with previous modelling studies, which indicate that global ozone concentrations should be increasing during the early part of the twenty-first century as a result of increasing precursor emissions, especially at northern mid-latitudes, with western North America being particularly sensitive to rising Asian emissions. We suggest that the observed increase in springtime background ozone mixing ratio may hinder the USA s compliance with its ozone air quality standard.

  18. Ozone flux to vegetation and its relationship to plant response and ambient air quality standards

    NASA Astrophysics Data System (ADS)

    Musselman, Robert C.; Massman, William J.

    The National Ambient Air Quality Standard (NAAQS) for ozone is based on occurrences of the maximum 8 h average ambient ozone concentration. However, biologists have recommended a cumulative ozone exposure parameter to protect vegetation. In this paper we propose a third alternative which uses quantifiable flux-based numerical parameters as a replacement for cumulative ambient parameters. Herein we discuss the concept of ozone flux as it relates to plant response and the NAAQS, and document information needed before a flux-based ozone NAAQS for vegetation can be implemented. Additional research is needed in techniques for determining plant uptake and in the quantification of plant defensive mechanisms to ozone. Models which include feedback mechanisms should be developed to relate ozone flux, loading, and detoxification with photosynthesis and plant productivity.

  19. Effect of pollutant gases on ozone production by simulated solar radiation

    NASA Technical Reports Server (NTRS)

    Wong, E. L.; Bittker, D. A.

    1974-01-01

    Experiments using simulated solar radiation in a chamber, with a controlled atmospheric pressure near 1 atmosphere, were conducted to evaluate O3 production. The effects of CO and H2O were analyzed to determine if the CO and H2O addition could reduce NO destruction of O3. The results show that NO is destroyed while destroying O3.

  20. Optimization of some additives to improve protease production under SSF.

    PubMed

    Tunga, R; Banerjee, R; Bhattacharyya, B C

    2001-11-01

    In a locally isolated Rhizopus oryzae strain highest-production of protease (388.54/g wheat bran) was observed in presence of Tween-80 and dioctyl sodium sulfosuccinate individually at 40mg/g wheat bran concentration. Under solid state fermentation biotin (0.0025mg/g wheat bran); Ca2+ (0.05mg/g wheat bran) and 1-Naphthyl acetic acid (0.01mg/g wheat bran) also showed some inducing effect on the synthesis of the enzyme protease by solid state fermentation. PMID:11906108

  1. The observed response of ozone production to the policy-driven decrease of NOx and CO emissions in the Baltimore/Washington area

    NASA Astrophysics Data System (ADS)

    Roberts, S. J.; Hosley, K.; Ren, X.; Wolfe, G.; Dickerson, R. R.; Salawitch, R. J.

    2015-12-01

    The nonlinearity of ozone production has important policy implications as cities continue to decrease NOx, CO, and other important ozone precursors. Observations in the Baltimore/Washington area from 1970 through 2014 demonstrate reductions in NOx and CO emissions due to policy implementation leading to dramatic improvement in air quality. We will analyze the response of the reactivity of ozone, NOx, and VOC to these emission reductions in the Baltimore/Washington area using the University of Washington Chemical Model (UWCMv2.2). This model allows us to evaluate this response using multiple gas-phase chemical mechanisms. With this model, we will also compare and contrast the response of modeled ozone to reduced NOx and CO concentrations across multiple chemical mechanisms.

  2. Global crop yield reductions due to surface ozone exposure: 2. Year 2030 potential crop production losses and economic damage under two scenarios of O 3 pollution

    NASA Astrophysics Data System (ADS)

    Avnery, Shiri; Mauzerall, Denise L.; Liu, Junfeng; Horowitz, Larry W.

    2011-04-01

    calculations of crop production and economic losses are highly conservative. Our results suggest that O 3 pollution poses a growing threat to global food security even under an optimistic scenario of future ozone precursor emissions. Further efforts to reduce surface O 3 concentrations thus provide an excellent opportunity to increase global grain yields without the environmental degradation associated with additional fertilizer application or land cultivation.

  3. Additive Manufacturing in Production: A Study Case Applying Technical Requirements

    NASA Astrophysics Data System (ADS)

    Ituarte, Iñigo Flores; Coatanea, Eric; Salmi, Mika; Tuomi, Jukka; Partanen, Jouni

    Additive manufacturing (AM) is expanding the manufacturing capabilities. However, quality of AM produced parts is dependent on a number of machine, geometry and process parameters. The variability of these parameters affects the manufacturing drastically and therefore standardized processes and harmonized methodologies need to be developed to characterize the technology for end use applications and enable the technology for manufacturing. This research proposes a composite methodology integrating Taguchi Design of Experiments, multi-objective optimization and statistical process control, to optimize the manufacturing process and fulfil multiple requirements imposed to an arbitrary geometry. The proposed methodology aims to characterize AM technology depending upon manufacturing process variables as well as to perform a comparative assessment of three AM technologies (Selective Laser Sintering, Laser Stereolithography and Polyjet). Results indicate that only one machine, laser-based Stereolithography, was feasible to fulfil simultaneously macro and micro level geometrical requirements but mechanical properties were not at required level. Future research will study a single AM system at the time to characterize AM machine technical capabilities and stimulate pre-normative initiatives of the technology for end use applications.

  4. Corona discharge influences ozone concentrations near rats.

    PubMed

    Goheen, Steven C; Gaither, Kari; Anantatmula, Shantha M; Mong, Gary M; Sasser, Lyle B; Lessor, Delbert

    2004-02-01

    Ozone can be produced by corona discharge either in dry air or when one electrode is submerged in water. Since ozone is toxic, we examined whether ozone production by corona near laboratory animals could reach levels of concern. Male rats were exposed to a corona discharge and the concentration of ozone produced was measured. The resulting concentration of ozone ranged from ambient levels to 250 ppb when animals were located 1 cm from a 10 kV source. Similar ozone concentrations were observed when a grounded water source was present. Possible explanations for, as well as concerns regarding, ozone production under these conditions are discussed. PMID:14735560

  5. Minireview: the health implications of water treatment with ozone

    SciTech Connect

    Carmichael, N.G.; Winder, C.; Borges, S.H.; Backhouse, B.L.; Lewis, P.D.

    1982-01-11

    Ozone is a highly efficient disinfectant which may have significant advantages in water treatment compared to chlorine. It has, however, been shown that mutagenic and possibly carcinogenic byproducts may be produced under certain conditions of ozonation. Light chlorination following ozonization may meet the highest standards of disinfection. In addition the destruction of much of the organic matter by prior ozone treatment may well result in less harmful chlorinated and brominated products in the finished water. In many cases ozone treatment alone may suffice. It would be desirable to test with long term in vivo experiments which of the alternatives produces the best combination of microbiologically clean and pleasant water with minimum mutagenic and carcinogenic effect.

  6. Comparison of Suomi-NPP OMPS total column ozone with Brewer and Dobson spectrophotometers measurements

    NASA Astrophysics Data System (ADS)

    Bai, Kaixu; Liu, Chaoshun; Shi, Runhe; Gao, Wei

    2015-09-01

    The objective of this study is to evaluate the accuracy of the daily nadir total column ozone products derived from the nadir mapper instrument on the Ozone Mapping and Profiler Suite (OMPS) flying onboard the Suomi National Polar-orbiting Partnership satellite (S-NPP) launched as a part of the Joint Polar Satellite System (JPSS) program between NOAA and NASA. Since NOAA is already operationally processing OMPS nadir total ozone products, evaluations were made in this study on the total column ozone research products generated by NASA's science team, utilizing the latest version of their Backscatter Ultraviolet (BUV) retrieval algorithms, to provide insight into the performance of the operation system. Comparisons were made with globally distributed ground-based Brewer and Dobson spectrophotometer total column ozone measurements. Linear regressions show fair agreement between OMPS and ground-based total column ozone measurements with a root-mean-square error (RMSE) of approximately 3% (10 DU). The comparison results indicate that the OMPS total column ozone data are 0.59% higher than the Brewer measurements with a standard deviation of 2.82% while 1.09% higher than the Dobson measurements with a standard deviation of 3.27%. Additionally, the variability of relative differences between OMPS and ground total column ozone were analyzed as a function of latitude, time, viewing geometry, and total column ozone value. Results show a 2% bias over most latitudes and viewing conditions when total column ozone value varies between 220 DU and 450 DU.

  7. Understanding HONO concentrations, its role as a hydroxyl radical source and the impact on summertime ozone production in London

    NASA Astrophysics Data System (ADS)

    Stone, D. J.; Whalley, L. K.; Hopkins, J. R.; Holmes, R. E.; Lee, J. D.; Hamilton, J. F.; Laufs, S.; Kleffmann, J.; Heard, D. E.

    2014-12-01

    Understanding the chemistry of free-radicals in the atmosphere is necessary to understand the lifetime of primary pollutants and production of secondary pollutants, such as ozone. In the urban environment, field observations of HONO have revealed elevated concentrations persisting throughout the day and subsequent modelling studies have identified HONO as the major OH precursor (e.g. Elshorbany et al. 2009). Attempts to reproduce the strong daytime HONO signature in models, however, have revealed that the currently known chemistry is unable to account for the levels observed. Here we present simultaneous measurements of OH, HO2, RO2 and HONO made during the Clean air for London project in the summer of 2012. HONO concentrations were observed to build up throughout the night, with concentrations exceeding 2ppbV on several nights. Daytime concentrations were lower, but ~ 300 pptv was observed to persist throughout the afternoon. Zero dimensional box modelling studies, constrained with the detailed MCM chemistry and to the measured HONO, suggest that HONO makes up ~85% of the primary OH budget and just over 50% of the total primary radical budget at noon. The model, however, greatly over-predicts the OH concentrations (and HO2 and RO2concentrations) observed. Unconstrained to HONO, the basic model is unable to reproduce the measured HONO concentrations. A source of HONO from the reaction of NO2 with HO2.H2O, as postulated by Li et al. (2014), can enhance HONO concentrations considerably and also reduces the discrepancy between modelled and measured radicals by reducing the fraction of HONO acting as a net radical source. The model still underestimates the observed HONO by ~ 80% at noon, suggesting that this portion of HONO should still be considered as a primary radical source. The net in-situ ozone production estimated from the measured peroxy radical concentrations and their reaction with NO is sufficient to account for the daily increases in ozone that were

  8. Understanding HONO concentrations in London, its role as a hydroxyl radical source and the impact on summertime ozone production

    NASA Astrophysics Data System (ADS)

    Whalley, Lisa; Lee, James; Stone, Daniel; Hamilton, Jacqueline; Holmes, Rachel; Hopkins, James; Laufs, Sebastian; Kleffmann, Jörg; Heard, Dwayne

    2015-04-01

    Understanding the chemistry of free-radicals in the atmosphere is necessary to understand the lifetime of primary pollutants and the production of secondary pollutants, such as ozone and organic aerosol. In the urban environment, field observations of HONO have revealed elevated concentrations persisting throughout the day and subsequent modelling studies have identified HONO as the major OH precursor. Attempts to reproduce the strong daytime HONO signature in models, however, have revealed that the currently known chemistry is unable to account for the levels observed. Here we present simultaneous measurements of OH, HO2, RO2, OH reactivity and HONO made during the Clean Air for London project in the summer of 2012. HONO concentrations were observed to build up throughout the night, with concentrations exceeding 2 ppbV on several nights. Daytime concentrations were lower, but ~ 300 pptv was observed to persist throughout the afternoon. Box modelling studies, using the Master Chemical Mechanism (MCM) and constrained to the measured HONO, suggest that HONO makes up ~85% of the primary OH budget and just under 50% of the total primary radical budget at noon. The model, however, significantly over-predicts the OH concentrations (and HO2 and RO2 concentrations) observed. Unconstrained to HONO, the basic model is unable to reproduce the measured HONO concentrations. A source of HONO from the reaction of NO2 with HO2.H2O, as postulated by Li et al. (Science, 344, 292, 2014), can enhance HONO concentrations considerably and also reduces the discrepancy between modelled and measured radicals by reducing the fraction of HONO acting as a net radical source. With this process included, the model still underestimates the observed HONO by ~ 69% at noon, suggesting that this portion of HONO should still be considered as a primary radical source. The net in-situ ozone production estimated from the measured peroxy radical concentrations and their reaction with NO is sufficient to

  9. The Unique OMI HCHO/NO2 Feature During the 2008 Beijing Summer Olympics: Implications for Ozone Production Sensitivity

    NASA Technical Reports Server (NTRS)

    Witte, J. C.; Duncan, B. N.; Douglass, A. R.; Kurosu, T. P.; Chance, K.; Retscher, C.

    2010-01-01

    In preparation of the Beijing Summer Olympic and Paralympics Games, strict controls were imposed between July and September 2008 on motor vehicle traffic and industrial emissions to improve air quality for the competitors. We assessed chemical sensitivity of ozone production to these controls using Ozone Monitoring Instrument (OMI) column measurements of formaldehyde (HCHO) and nitrogen dioxide (NO2), where their ratio serves as a proxy for the sensitivity. During the emission controls, HCHO/NO2 increased and indicated a NOx-limited regime, in contrast to the same period in the preceding three years when the ratio indicates volatile organic carbon (VOC)-limited and mixed NOx-VOC-limited regimes. After the emission controls were lifted, observed NO2 and HCHO/NO2 returned to their previous values. The 2005-2008 OMI record shows that this transition in regimes was unique as ozone production in Beijing was rarely NOx-limited. OMI measured summertime increases in HCHO of around 13% in 2008 compared to prior years, the same time period during which MODIS vegetation indices increased. The OMI HCHO increase may be due to higher biogenic emissions of HCHO precursors, associated with Beijing's greening initiative for the Olympics. However, NO2 and HCHO were also found to be well-correlated during the summer months. This indicates an anthropogenic VOC contribution from vehicle emissions to OMI HCHO and is a plausible explanation for the relative HCHO minimum observed in August 2008, concurrent with a minimum in traffic emissions. We calculated positive trends in 2005-2008 OMI HCHO and NO2 of about +1 x 10(exp 14) Molec/ square M-2 and +3 x 10(exp 13) molec CM-2 per month, respectively. The positive trend in NO2 may be an indicator of increasing vehicular traffic since 2005, while the positive trend in HCHO may be due to a combined increase in anthropogenic and biogenic emissions since 2005.

  10. A Comparison of OMPS Total Column Ozone Data with Data from Ground Stations

    NASA Astrophysics Data System (ADS)

    Labow, G. J.; McPeters, R. D.; Yang, E. S.; Haffner, D. P.

    2015-12-01

    The total column ozone dataset from Suomi NPP Ozone Mapping Profiler Suite (OMPS) has been recently reprocessed with new instrument calibrations. An overview will be presented systematically comparing ozone values to an ensemble of Brewer and Dobson spectrophotometers. The comparisons were made as a function of latitude, solar zenith angle, reflectivity and total ozone. The nadir mapper overpass data are derived from the single best match measurement, almost always located within one degree of the ground station and usually made within an hour and half of local noon. The total column ozone measurements from the Nadir Profiler instrument have also been compared to the ground-based measurements and these results will also be shown. An additional level 3 gridded product, 1 degree by 1 degree has been produced with corrections implemented in order to minimize the cross-track biases. This corrected data set yields a less noisy product and a smoother gridded ozone map.

  11. Analysis of 2010-2014 Ground-Level Ozone at Trinidad Head, CA

    NASA Astrophysics Data System (ADS)

    Lennartson, E.; McClure-Begley, A.; Petropavlovskikh, I. V.; Leonard, M.

    2015-12-01

    High concentrations of ground-level ozone in the troposphere have negative impacts on human health and other biological organisms. As the US Environmental Protection Agency (EPA) is proposing to lower the National Ambient Air Quality Standard (NAAQS) for ozone from 75 to 65-70 parts per billion (ppb), it is important to further study the relationship between both anthropogenic and natural pollutants that lead to production and accumulation of surface ozone. Ground-level ozone data from Trinidad Head, California (THD) was analyzed from 2010-2014 to investigate the factors contributing to high ground-level ozone events. For this research project, a high ozone event was defined as ground-level ozone readings greater than the 90th percentile of the seasonal ozone variability observed during the 2003-2014 period. The ozone exceedances were also required to last for three continuous hours or more. Meteorological parameters, such as wind speed and synoptic patterns, were taken into account. In addition, impacts related to stratospheric intrusions, Asian pollution transport, and the influence of local forest fires were considered. We show that high ground-level ozone events at THD occur during a dominant wind direction and are highly dependent on the origin of the air mass. This understanding of enhanced ground-level ozone drivers will provide a foundational knowledge of climate adaptation and mitigation with improved scientific understanding of the changing climate and its impacts.

  12. Photochemical ozone production in tropical squall line convection during NASA Global Tropospheric Experiment/Amazon Boundary Layer Experiment 2A

    NASA Technical Reports Server (NTRS)

    Pickering, Kenneth E.; Thompson, Anne M.; Tao, Wei-Kuo; Simpson, Joanne; Scala, John R.

    1991-01-01

    The role of convection was examined in trace gas transport and ozone production in a tropical dry season squall line sampled on August 3, 1985, during NASA Global Tropospheric Experiment/Amazon Boundary Layer Experiment 2A (NASA GTE/ABLE 2A) in Amazonia, Brazil. Two types of analyses were performed. Transient effects within the cloud are examined with a combination of two-dimensional cloud and one-dimensional photochemical modeling. Tracer analyses using the cloud model wind fields yield a series of cross sections of NO(x), CO, and O3 distribution during the lifetime of the cloud; these fields are used in the photochemical model to compute the net rate of O3 production. At noon, when the cloud was mature, the instantaneous ozone production potential in the cloud is between 50 and 60 percent less than in no-cloud conditions due to reduced photolysis and cloud scavenging of radicals. Analysis of cloud inflows and outflows is used to differentiate between air that is undisturbed and air that has been modified by the storm. These profiles are used in the photochemical model to examine the aftereffects of convective redistribution in the 24-hour period following the storm. Total tropospheric column O3 production changed little due to convection because so little NO(x) was available in the lower troposphere. However, the integrated O3 production potential in the 5- to 13-km layer changed from net destruction to net production as a result of the convection. The conditions of the August 3, 1985, event may be typical of the early part of the dry season in Amazonia, when only minimal amounts of pollution from biomass burning have been transported into the region.

  13. Two Years of Ozone Vertical Profiles Collected from Aircraft over California and the Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Austerberry, D.; Yates, E. L.; Roby, M.; Chatfield, R. B.; Iraci, L. T.; Pierce, B.; Fairlie, T. D.; Johnson, B. J.; Ives, M.

    2012-12-01

    Tropospheric ozone transported across the Pacific Ocean has been strongly suggested to contribute substantially to surface ozone levels at several sites within Northern California's Sacramento Valley. Because this contribution can affect a city's ability to meet regulatory ozone limits, the influence of Pacific ozone transport has implications for air quality control strategies in the San Joaquin Valley (SJV). The Alpha Jet Atmospheric Experiment is designed to collect a multi-year data set of tropospheric ozone vertical profiles. Forty-four flights with ozone profiles were conducted between February 2nd, 2011 and August 9th, 2012, and approximately ten more flights are expected in the remainder of 2012. Twenty marine air profiles have been collected at sites including Trinidad Head and two locations tens of kilometers offshore at 37° N latitude. Good agreement is seen with ozonesondes launched from Trinidad Head. Additional profiles over Merced, California were obtained on many of these flight days. These in-situ measurements were conducted during spiral descents of H211's Alpha Jet at mid-day local times using a 2B Technologies Dual Beam Ozone Monitor. Hourly surface ambient ozone data were obtained from the California Air Resources Board's SJV monitoring sites. For each site, the Pearson linear correlation coefficient was calculated between ozone in a 300m vertical layer of an offshore profile and the surface site at varying time offsets from the time of the profile. Each site's local and regional ozone production component was estimated and removed. The resulting correlations suggest instances of Pacific ozone transport following some of the offshore observations. Real-Time Air Quality Modeling System (RAQMS) products constrained by assimilated satellite data model the transport of ozone enhancements and guide flight planning. RAQMS hindcasts also suggest that ozone transport to the surface of the SJV basin occurred following some of these offshore profiles

  14. Estimating the Tropospheric Ozone Distribution by the Assimilation of Satellite Data

    NASA Technical Reports Server (NTRS)

    Hayashi, Hiroo; Stajner, Ivanka; Winslow, Nathan; Jones, Dylan B. A.; Pawson, Steven; Thompson, Anne M.

    2003-01-01

    Tropospheric ozone is important to the environment, because it acts as a strong oxidant to control the concentrations of many reduced gases (methane, carbon monoxide, ... ), its radiative forcing plays a significant role in the greenhouse effect, and direct contact with ozone is harmful to human health. Tropospheric ozone, whose main sources are intrusion from the stratosphere and chemical production from source gases associated with urban pollution or biomass burning, varies on a wide range of spatial and temporal scales. Its transport and chemistry can be influenced by weather, seasonal, or multiannual variability. Despite the importance of tropospheric ozone, it contributes only about 10% of the total ozone loading in the atmosphere. Consequently, satellite instruments lose sensitivity below the stratospheric ozone peak, and provide little information about middle and lower tropospheric ozone. This talk will discuss recent modifications made to the satellite ozone data assimilation system at NASA's Data Assimilation Office (DAO) in order to provide better tropospheric ozone columns and profiles. We use a version of the system that assimilates only the data from the Solar Backscatter UltraViolet/2 (SBUV/2) instrument. The quality of the assimilated ozone in the tropical troposphere is evaluated by comparison with independent observations obtained from the Southern Hemispheric Additional Ozonesondes (SHADOZ) network. It is shown that the quality of ozone fields is sensitive to the winds used in the transport model. Increasing the vertical resolution of the model also has a beneficial impact. The assimilated ozone in the lower troposphere was substantially improved by inclusion of tropospheric ozone production, loss, and dry deposition rates from the Harvard GEOS-CHEM model. The mechanisms behind these results will be examined and the implications for our understanding of tropospheric ozone will be discussed.

  15. 2D simulation of active species and ozone production in a multi-tip DC air corona discharge

    NASA Astrophysics Data System (ADS)

    Meziane, M.; Eichwald, O.; Sarrette, J. P.; Ducasse, O.; Yousfi, M.

    2011-11-01

    The present paper shows for the first time in the literature a complete 2D simulation of the ozone production in a DC positive multi-tip to plane corona discharge reactor crossed by a dry air flow at atmospheric pressure. The simulation is undertaken until 1 ms and involves tens of successive discharge and post-discharge phases. The air flow is stressed by several monofilament corona discharges generated by a maximum of four anodic tips distributed along the reactor. The nonstationary hydrodynamics model for reactive gas mixture is solved using the commercial FLUENT software. During each discharge phase, thermal and vibrational energies as well as densities of radical and metastable excited species are locally injected as source terms in the gas medium surrounding each tip. The chosen chemical model involves 10 neutral species reacting following 24 reactions. The obtained results allow us to follow the cartography of the temperature and the ozone production inside the corona reactor as a function of the number of high voltage anodic tips.

  16. Mutagenic activity of the products of ozone reaction with propylene in the presence and absence of nitrogen dioxide

    SciTech Connect

    Shepson, P.B.; Kleindienst, T.E.; Edney, E.O.; Cuplitt, L.T.; Claxton, L.D.

    1985-11-01

    This study was performed to determine if propylene reaction with ozone could account for the large mutagenic activity we have observed in irradiated propylene/NO/sub x/ mixtures. In a 22.7-m/sup 3/ flow mode smog chamber, 5.4 ppm of propylene was allowed to react with 0.9 ppm of ozone either in the presence or in the absence of 0.2 ppm of nitrogen dioxide (at 25 /sup 0/C in the dark). The steady-state reactant and product distribution was then tested for total mutagenic activity by exposing Salmonella typhimurium strain TA100 to the gas-phase chamber effluent. The total product dosage in the test plates was varied by exposing them for 0, 5, 10, 15, and 20 h. Salmonella typhimurium survivor levels were obtained at each length of exposure. The number of revertants per plate increased at a rate of approx. 4-5 per hour, while the survivor level decreased throughout the exposure. Most of the total mutagenic activity can be accounted for by the presence of formaldehyde. The total mutagenic activity observed was, however, much smaller than that observed in the irradiated propylene/NO/sub x/ system, for comparable amounts of propylene consumed.

  17. Mutagenic activity associated with by-products of drinking water disinfection by chlorine, chlorine dioxide, ozone and UV-irradiation.

    PubMed

    Zoeteman, B C; Hrubec, J; de Greef, E; Kool, H J

    1982-12-01

    A retrospective epidemiological study in The Netherlands showed a statistical association between chlorination by-products in drinking water and cancer of the esophagus and stomach for males. A pilot-plant study with alternative disinfectants was carried out with stored water of the Rivers Rhine and Meuse. It was demonstrated that the increase of direct acting mutagens after treatment with chlorine dioxide is similar to the effect of chlorination. Ozonation of Rhine water reduced the mutagenic activity for Salmonella typhimurium TA 98 both with and without metabolic activation. UV alone hardly affects the mutagenicity of the stored river water for S. typh. TA 98. In all studies, practically no mutagenic activity for S. typh. TA 100 was found. Although remarkable changes in the concentration of individual organic compounds are reported, the identity of the mutagens detected is yet unclear. Compounds of possible interest due to their removal by ozonation are 1,3,3-trimethyloxindole, dicyclopentadiene and several alkylquinolines. Compounds which might be responsible for the increased mutagenicity after chlorination are two brominated acetonitriles and tri(2-chlorethyl) phosphate. Furthermore, the concentration procedure with adsorption on XAD resin and the subsequent elution step may have affected the results. It is proposed to focus further research more on the less volatile by-products of disinfection than on the trihalomethanes. PMID:7151762

  18. Economic valuation of environmental benefits of removing pharmaceutical and personal care products from WWTP effluents by ozonation.

    PubMed

    Molinos-Senante, M; Reif, R; Garrido-Baserba, M; Hernández-Sancho, F; Omil, F; Poch, M; Sala-Garrido, R

    2013-09-01

    Continuous release of pharmaceutical and personal care products (PPCPs) present in effluents from wastewater treatment plants (WWTPs) is nowadays leading to the adoption of specific measures within the framework of the Directive 2000/60/EC (Water Framework Directive). The ozonation process, normally employed for drinking water production, has also proven its potential to eliminate PPCPs from secondary effluents in spite of their low concentrations. However, there is a significant drawback related with the costs associated with its implementation. This lack of studies is especially pronounced regarding the economic valuation of the environmental benefits associated to avoid the discharge of these pollutants into water bodies. For the first time the shadow prices of 5 PPCPs which are ethynilestradiol, sulfamethoxazole, diclofenac, tonalide and galaxolide from treated effluent using a pilot-scale ozonation reactor have been estimated. From non-sensitive areas their values are -73.73; -34.95; -42.20; -10.98; and -8.67 respectively and expressed in €/kg. They represent a proxy to the economic value of the environmental benefits arisen from undischarged pollutants. This paper contributes to value the environmental benefits of implementing post-treatment processes aimed to achieve the quality standards required by the Priority Substances Directive. PMID:23747556

  19. Effect of ozone on photosynthesis, vegetative growth and productivity of prunus salicina' in the San Joaquin Valley of California. (Year 3). Final report

    SciTech Connect

    Williams, L.E.; DeJong, T.M.; Retzlaff, W.A.

    1992-10-01

    In 1988, an experimental orchard of Cassleman plum (Prunus salicina) was planted in open-top-fumigation chambers and exposed for 4 growing seasons to three ozone concentrations near Fresno, California. During the third year of the study, mean 12-h ozone levels (1991) were 0.034 ppm in the charcoal filtered chambers, 0.050 ppm in the ambient air chambers, 0.94 ppm in the ambient plus added ozone chambers and 0.058 ppm in the no-chamber field plots. Chronic ozone stress has a detrimental effect on photosynthesis, stomatal conductance, leaf appearance and retention, trunk growth, and yield. Yield was 19.8 kg per tree in the charcoal filtered chambers, 15.9 kg/tree in the ambient air chambers, 6.8 kg/tree in the ambient air plus ozone chambers and 15.8 kg/tree in the no-chamber plots. Premature leaf drop and a 35 percent yield loss occurred in 1990 at mean daily ozone concentrations greater than 0.09 ppm (the California Ambient Air Quality Standard). In 1991 the yield loss increased to 65%, indicating cumulative impact on long term productivity.

  20. Effect of ozone on photosynthesis, vegetative growth and productivity of prunus salicina in the San Joaquin Valley of California. Final report

    SciTech Connect

    Williams, L.E.; DeJong, T.M.; Retzlaff, W.A.

    1991-10-31

    In 1988, an experimental orchard of Cassleman plum (Prunus salicina) was planted in open top fumigation chambers and exposed for 4 growing seasons to three ozone concentrations near Fresno, California. During the two years from orchard establishment to the first fruit bearing stage, mean 12-h ozone levels (1989) were 0.044 ppm in the charcoal filtered chambers, 0.059 ppm in the ambient air chambers, 0.111 ppm in the ambient plus added ozone chambers and 0.064 ppm in the no-chamber field plots. The 1990 ozone levels were 0.038 ppm, 0.050 ppm, 0.090 ppm, and 0.050 ppm, respectively. Chronic ozone stress has a detrimental effect on leaf appearance and retention, trunk growth, and yield during the orchard establishment period. Fruit production was 28 percent lower in the ambient exposures and 38 percent lower in the twice ambient exposures, compared to trees grown in filtered air chambers. Photosynthesis was reduced 11 percent and 40 percent respectively. Premature leaf drop occurred at mean daily ozone concentrations greater than 0.09 ppm (the California Ambient Air Quality Standard) and had an adverse impact on trunk growth.

  1. Identification of products formed during the heterogeneous nitration and ozonation of polycyclic aromatic hydrocarbons

    NASA Astrophysics Data System (ADS)

    Cochran, Richard E.; Jeong, Haewoo; Haddadi, Shokouh; Fisseha Derseh, Rebeka; Gowan, Alexandra; Beránek, Josef; Kubátová, Alena

    2016-03-01

    The 3- and 4-ring polycyclic aromatic hydrocarbons (PAHs) are the most abundant of PAHs in air particulate matter (PM). Thus we have investigated heterogeneous oxidation of 3- and 4-ring PAHs in a small-scale flow reactor using quartz filter as a support. Four representative PAHs, anthracene, phenanthrene, pyrene, and fluoranthene, were exposed to either NO2, O3 or NO2+O3 (NO3/N2O5) with a goal to identify and attempt quantification of major product distribution. A combination of gas chromatography with mass spectrometry (GC-MS) with/without derivatization and liquid chromatography with high resolution MS (LC-HRMS) was used for identification. For the first time, a comprehensive characterization of a broad range of products enabled identifying ketone/diketone, aldehyde, hydroxyl, and carboxylic acid PAH derivatives. Exposure to NO3/N2O5 (formed by reacting NO2 with O3, a more powerful reactant than either O3 or NO2) produced additional compounds not observed with either oxidant alone. Multiple isomers of nitrofluoranthene and, for the first time, nitrophenanthrene were identified. In addition hydroxy-nitro-PAH derivatives were observed for the reaction of anthracene with NO3/N2O5. Monitoring of specific common ions such as those of 176 and 205 m/z attributed to carbonyl phenanthrene and deprotonated phenanthrene ions respectively was shown to be a useful tool for identification of multiple pyrene oxidation products.

  2. Study on enhanced degradation of atrazine by ozonation in the presence of hydroxylamine.

    PubMed

    Yang, Jingxin; Li, Ji; Dong, Wenyi; Ma, Jun; Cao, Jie; Li, Tingting; Li, Jiayin; Gu, Jia; Liu, Pingxin

    2016-10-01

    Degradation of atrazine (ATZ) by ozonation in the presence of hydroxylamine (HA) was experimentally investigated in this study. The results showed approximately 80% of ATZ was degraded by ozonation in the presence of HA, while only 20% was degraded by ozonation alone. The obvious inhibition of the ATZ degradation by tert-butanol suggested the enhanced ATZ degradation by ozone/HA was primarily attributed to OH. The OH yield was determined to be 25.8%. Additionally, the optimum HA dosage for the ATZ degradation was 4μM, when the ozone dosage was 20μM. The effects of pH, bicarbonate and temperature on ATZ degradation by ozone/HA were investigated in details. Most importantly, the enhanced ATZ degradation by ozonation in the presence of HA was still observed in real water especially at acidic pHs. Furthermore, the potential mechanism of OH formation during the reaction of ozone with HA was proposed herein. Nine products were identified by UPLC/Q-TOF-MS system. The ATZ degradation involved dealkylation, dechlorination-hydroxylation and olefination. The evolutions of the concentrations of three available transformation products including deethylatrazine, deisopropylatrazine and deethyldeisopropylatrazine in ozone/HA were evaluated and compared with that in ozonation alone. PMID:27232722

  3. Total Ozone Prediction: Stratospheric Dynamics

    NASA Technical Reports Server (NTRS)

    Jackman, Charles H.; Kawa, S. Ramdy; Douglass, Anne R.

    2003-01-01

    The correct prediction of total ozone as a function of latitude and season is extremely important for global models. This exercise tests the ability of a particular model to simulate ozone. The ozone production (P) and loss (L) will be specified from a well- established global model and will be used in all GCMs for subsequent prediction of ozone. This is the "B-3 Constrained Run" from M&MII. The exercise mostly tests a model stratospheric dynamics in the prediction of total ozone. The GCM predictions will be compared and contrasted with TOMS measurements.

  4. Effects of stratospheric ozone recovery on photochemistry and ozone air quality in the troposphere

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Wu, S.; Huang, Y.; Wang, Y.

    2014-04-01

    There has been significant stratospheric ozone depletion since the late 1970s due to ozone-depleting substances (ODSs). With the implementation of the Montreal Protocol and its amendments and adjustments, stratospheric ozone is expected to recover towards its pre-1980 level in the coming decades. In this study, we examine the implications of stratospheric ozone recovery for the tropospheric chemistry and ozone air quality with a global chemical transport model (GEOS-Chem). With a full recovery of the stratospheric ozone, the projected increases in ozone column range from 1% over the low latitudes to more than 10% over the polar regions. The sensitivity factor of troposphere ozone photolysis rate, defined as the percentage changes in surface ozone photolysis rate for 1% increase in stratospheric ozone column, shows significant seasonal variation but is always negative with absolute value larger than one. The expected stratospheric ozone recovery is found to affect the tropospheric ozone destruction rates much more than the ozone production rates. Significant decreases in surface ozone photolysis rates due to stratospheric ozone recovery are simulated. The global average tropospheric OH decreases by 1.7%, and the global average lifetime of tropospheric ozone increases by 1.5%. The perturbations to tropospheric ozone and surface ozone show large seasonal and spatial variations. General increases in surface ozone are calculated for each season, with increases by up to 0.8 ppbv in the remote areas. Increases in ozone lifetime by up to 13% are found in the troposphere. The increased lifetimes of tropospheric ozone in response to stratospheric ozone recovery enhance the intercontinental transport of ozone and global pollution, in particular for the summertime. The global background ozone attributable to Asian emissions is calculated to increase by up to 15% or 0.3 ppbv in the Northern Hemisphere in response to the projected stratospheric ozone recovery.

  5. Tropospheric Ozone and Photochemical Smog

    NASA Astrophysics Data System (ADS)

    Sillman, S.

    2003-12-01

    emitted species, in a process that is driven by sunlight and is accelerated by warm temperatures. This smog is largely the product of gasoline-powered engines (especially automobiles), although coal-fired industry can also generate photochemical smog. The process of photochemical smog formation was first identified by Haagen-Smit and Fox (1954) in association with Los Angeles, a city whose geography makes it particularly susceptible to this type of smog formation. Sulfate aerosols and organic particulates are often produced concurrently with ozone, giving rise to a characteristic milky-white haze associated with this type of air pollution.Today ozone and particulates are recognized as the air pollutants that are most likely to affect human health adversely. In the United States, most major metropolitan areas have periodic air pollution events with ozone in excess of government health standards. Violations of local health standards also occur in major cities in Canada and in much of Europe. Other cities around the world (especially Mexico City) also experience very high ozone levels. In addition to urban-scale events, elevated ozone occurs in region-wide events in the eastern USA and in Western Europe, with excess ozone extending over areas of 1,000 km2 or more. Ozone plumes of similar extent are found in the tropics (especially in Central Africa) at times of high biomass burning (e.g., Jenkins et al., 1997; Chatfield et al., 1998). In some cases ozone associated with biomass burning has been identified at distances up to 104 km from its sources (Schultz et al., 1999).Ozone also has a significant impact on the global troposphere, and ozone chemistry is a major component of global tropospheric chemistry. Global background ozone concentrations are much lower than urban or regional concentrations during pollution events, but there is evidence that the global background has increased as a result of human activities (e.g., Wang and Jacob, 1998; Volz and Kley, 1988). A rise in

  6. 40 CFR 82.18 - Availability of production in addition to baseline production allowances for class II controlled...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....20 in order to produce with the additional production allowances. (2) Trade from a Party—Information... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Availability of production in addition to baseline production allowances for class II controlled substances. 82.18 Section 82.18...

  7. 40 CFR 82.9 - Availability of production allowances in addition to baseline production allowances for class I...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... allowances allocated under § 82.6 and § 82.7 in order to produce with the additional production allowances... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Availability of production allowances in addition to baseline production allowances for class I controlled substances. 82.9 Section...

  8. An MCM modeling study of nitryl chloride (ClNO2) impacts on oxidation, ozone production and nitrogen oxide partitioning in polluted continental outflow

    NASA Astrophysics Data System (ADS)

    Riedel, T. P.; Wolfe, G. M.; Danas, K. T.; Gilman, J. B.; Kuster, W. C.; Bon, D. M.; Vlasenko, A.; Li, S.-M.; Williams, E. J.; Lerner, B. M.; Veres, P. R.; Roberts, J. M.; Holloway, J. S.; Lefer, B.; Brown, S. S.; Thornton, J. A.

    2013-11-01

    Nitryl chloride (ClNO2) is produced at night by reactions of dinitrogen pentoxide (N2O5) on chloride containing surfaces. ClNO2 is photolyzed during the morning hours after sunrise to liberate highly reactive chlorine atoms (Cl·). This chemistry takes place primarily in polluted environments where the concentrations of N2O5 precursors (nitrogen oxide radicals and ozone) are high, though it likely occurs in remote regions at lower intensities. Recent field measurements have illustrated the potential importance of ClNO2 as a daytime Cl· source and a nighttime NOx reservoir. However, the fate of the Cl· and the overall impact of ClNO2 on regional photochemistry remain unclear. To this end, we have incorporated ClNO2 production, photolysis, and subsequent Cl· reactions into an existing Master Chemical Mechanism (MCM version 3.2) box model framework using observational constraints from the CalNex 2010 field study. Cl· reactions with a set of alkenes and alcohols, and the simplified multiphase chemistry of N2O5, ClNO2, HOCl, ClONO2, and Cl2, none of which are currently part of the MCM, have been added to the mechanism. The presence of ClNO2 produces significant changes to oxidants, ozone, and nitrogen oxide partitioning, relative to model runs excluding ClNO2 formation. From a nighttime maximum of 1.5 ppbv ClNO2, the daytime maximum Cl· concentration reaches 1 × 105 atoms cm-3 at 7 a.m., reacting mostly with a large suite of volatile organic compounds (VOC) to produce 2.2 times more organic peroxy radicals in the morning than in the absence of ClNO2. In the presence of several ppbv of nitrogen oxide radicals (NOx = NO + NO2), these perturbations lead to similar enhancements in hydrogen oxide radicals (HOx = OH + HO2). Neglecting contributions from HONO, the total integrated daytime radical source is 17% larger when including ClNO2, which leads to a similar enhancement in integrated ozone production of 15%. Detectable levels (tens of pptv) of chlorine containing

  9. An MCM modeling study of nitryl chloride (ClNO2) impacts on oxidation, ozone production and nitrogen oxide partitioning in polluted continental outflow

    NASA Astrophysics Data System (ADS)

    Riedel, T. P.; Wolfe, G. M.; Danas, K. T.; Gilman, J. B.; Kuster, W. C.; Bon, D. M.; Vlasenko, A.; Li, S.-M.; Williams, E. J.; Lerner, B. M.; Veres, P. R.; Roberts, J. M.; Holloway, J. S.; Lefer, B.; Brown, S. S.; Thornton, J. A.

    2014-04-01

    Nitryl chloride (ClNO2) is produced at night by reactions of dinitrogen pentoxide (N2O5) on chloride containing surfaces. ClNO2 is photolyzed during the morning hours after sunrise to liberate highly reactive chlorine atoms (Cl·). This chemistry takes place primarily in polluted environments where the concentrations of N2O5 precursors (nitrogen oxide radicals and ozone) are high, though it likely occurs in remote regions at lower intensities. Recent field measurements have illustrated the potential importance of ClNO2 as a daytime Cl· source and a nighttime NOx reservoir. However, the fate of the Cl· and the overall impact of ClNO2 on regional photochemistry remain poorly constrained by measurements and models. To this end, we have incorporated ClNO2 production, photolysis, and subsequent Cl· reactions into an existing master chemical mechanism (MCM version 3.2) box model framework using observational constraints from the CalNex 2010 field study. Cl· reactions with a set of alkenes and alcohols, and the simplified multiphase chemistry of N2O5, ClNO2, HOCl, ClONO2, and Cl2, none of which are currently part of the MCM, have been added to the mechanism. The presence of ClNO2 produces significant changes to oxidants, ozone, and nitrogen oxide partitioning, relative to model runs excluding ClNO2 formation. From a nighttime maximum of 1.5 ppbv ClNO2, the daytime maximum Cl· concentration reaches 1 × 105 atoms cm-3 at 07:00 model time, reacting mostly with a large suite of volatile organic compounds (VOC) to produce 2.2 times more organic peroxy radicals in the morning than in the absence of ClNO2. In the presence of several ppbv of nitrogen oxide radicals (NOx = NO + NO2), these perturbations lead to similar enhancements in hydrogen oxide radicals (HOx = OH + HO2). Neglecting contributions from HONO, the total integrated daytime radical source is 17% larger when including ClNO2, which leads to a similar enhancement in integrated ozone production of 15%. Detectable

  10. Vertical and Horizontal Measurements of Ambient Ozone over a Gas and Oil Production Area using a UAV Platform

    NASA Astrophysics Data System (ADS)

    Jensen, A.; Gowing, I.; Martin, R. S.

    2013-12-01

    During the 2013 wintertime Uintah Basin Ozone Study (UBOS13), an autonomous unmanned aerial vehicle (UAV) platform, coupled with an on-board UV ozone monitor, flew several spatial profiles near the location (Horse Pool) of other concentrated measurements by other co-investigators. The airframe, part of the Utah Water Research Laboratory's (UWRL) AggieAir UAV program, consisted of a custom-built, battery-operated plane with and 2.4 m (8 ft) wing span and a 12.7 cm x 12.7 cm x 30.5 cm payload bay with a carrying capacity of approximately 2.0 kg. With the current power system, the fully-loaded AggieAir UAV can fly for approximately 45 minutes at a nominal airspeed of 13.4 m/s (30 mph). The system can be operated either in manual control or be flown autonomously following preprogrammed waypoints via a built in GPS system. The AggieAir UAV systems were primarily designed for photographic and telemetry tracking projects. For the UBOS13 flights, a 2B Technologies Model 205 Ozone (O3) monitor was modified for minimal weight optimization, wrapped with lightweight insulation and secured into the UAV payload bay. Additionally, HOBO Model H08-001-02 shielded temperature/datalogger was secured to the exterior of the UAV from parallel thermal profile determination. During the study period, three demonstration flight profiles were obtained on February 17 and 18, 2013: two vertical 'curtain' profiles and a pair of 'stacked' horizontal profiles. As recorded by numerous ground-based monitoring sites, the ozone during the UAV test periods was characterized by initial trends of daytime O3 maximums over 130 ppb, followed by a meteorological front partially ventilating the Basin on the evening of Feb. 17th leading to decreased O3 minimums around 40 ppb. However, the ground level O3 rebuilt quickly to ground level maximums approaching 100 ppb. The vertical 'curtain' flown on the evening of Feb. 17th only reached a maximum elevation of about 2160 m ASL (600 m AGL) due to encountering

  11. Ozone in the Atmosphere: II. The Lower Atmosphere.

    ERIC Educational Resources Information Center

    Phillips, Paul; Pickering, Pam

    1991-01-01

    Described are the problems caused by the increased concentration of ozone in the lower atmosphere. Photochemical pollution, mechanisms of ozone production, ozone levels in the troposphere, effects of ozone on human health and vegetation, ozone standards, and control measures are discussed. (KR)

  12. 78 FR 53486 - Addition of Round-Trip Mailer Product to the Competitive Product List

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... Round-Trip Mailer Product to the Competitive Product List AGENCY: Postal Service TM ACTION: Notice... Commission to add a product called ``Round-Trip Mailer'' to the competitive product list. DATES: Effective... (Commission) a request to add a ``Round-Trip Mailer'' product to its competitive product list, pursuant...

  13. Improved milk production efficiency in early lactation dairy cattle with dietary addition of a developmental fibrolytic enzyme additive.

    PubMed

    Holtshausen, L; Chung, Y-H; Gerardo-Cuervo, H; Oba, M; Beauchemin, K A

    2011-02-01

    A 3-part study was conducted to evaluate the effect of a developmental fibrolytic enzyme additive on the digestibility of selected forages and the production performance of early-lactation dairy cows. In part 1, 4 replicate 24-h batch culture in vitro incubations were conducted with alfalfa hay, alfalfa silage, and barley silage as substrates and ruminal fluid as the inoculum. A developmental fibrolytic enzyme additive (AB Vista, Marlborough, UK) was added at 5 doses: 0, 0.5, 1.0, 1.5, and 2.0 μL/g of forage dry matter (DM). After the 24-h incubation, DM, neutral detergent fiber (NDF), and acid detergent fiber (ADF) disappearance were determined. For alfalfa hay, DM, NDF, and ADF disappearance was greater at the highest dosage compared with no enzyme addition. Barley silage NDF and ADF and alfalfa silage NDF disappearance tended to be greater for the highest enzyme dosage compared with no enzyme addition. In part 2, 6 ruminally cannulated, lactating Holstein dairy cows were used to determine in situ degradation of alfalfa and barley silage, with (1.0 mL/kg of silage DM) and without added enzyme. Three cows received a control diet (no enzyme added) and the other 3 received an enzyme-supplemented (1.0 mL/kg of diet DM) diet. Enzyme addition after the 24h in situ incubation did not affect the disappearance of barley silage or alfalfa silage. In part 3, 60 early-lactation Holstein dairy cows were fed 1 of 3 diets for a 10-wk period: (1) control (CTL; no enzyme), (2) low enzyme (CTL treated with 0.5 mL of enzyme/kg of diet DM), and (3) high enzyme (CTL treated with 1.0 mL of enzyme/kg of diet DM). Adding enzyme to the diet had no effect on milk yield, but dry matter intake was lower for the high enzyme treatment and tended to be lower for the low enzyme treatment compared with CTL. Consequently, milk production efficiency (kg of 3.5% fat-corrected milk/kg of DM intake) linearly increased with increasing enzyme addition. Cows fed the low and high enzyme diets were 5

  14. Activation of phospholipase A{sub 2} in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine liposomes containing lipid ozonation products

    SciTech Connect

    Salgo, M.G.; Squadrito, G.L.; Pryor, W.A.

    1994-05-01

    The activation of phospholipase A{sub 2} (PLA{sub 2}) by lipid ozonation products is reported. The principal products from the ozonation of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) are 1-palmitoyl-2-[8-3(5-octyl-1,2,4-trioxolan-3-yl)octanoyl]--sn-glycero-3-phosphocholine (PC-Criegee ozonide) and 1-palmitoyl-2-(9-oxononanoyl)-sn-glycero-3-phosphocholine (PC-aldehyde). Here we test the hypothesis that these two compounds are mediators of ozone toxicity. Using POPC vesicles, we find that PLA{sub 2} recognizes and hydrolyzes PC-Criegee ozonide at the same rate as that of arachidonic acid. Although the PC-aldehyde is not a substrate for PLA{sub 2}, the enzymatic rate of hydrolysis by PLA{sub 2} of unaltered fatty acids incorporated into POPC is enhanced when PC-aldehyde is present in the bilayer. Thus, both PC-Criegee ozonide and PC-aldehyde alter the activity of PLA{sub 2}, perhaps via an effect on membrane packing order. The capacity of PLA{sub 2} to recognize the PC-Criegee, and therefore ozone-induced damage, suggests a detoxification property of the enzyme and also a role in maintaining the structural properties of bilayer membranes that have been altered by exposure to ozone. 29 refs., 3 figs., 1 tab.

  15. Excipients and additives: hidden hazards in drug products and in product substitution.

    PubMed Central

    Napke, E; Stevens, D G

    1984-01-01

    The excipients and additives in drug formulations have been described as inert because they do not have an active role in the prevention or treatment of particular ailments. This has led to the misconception among physicians, pharmacists, drug manufacturers and the public that excipients are harmless and unworthy of mention. In fact, pharmacists are allowed to substitute drug formulations, without regard to the excipients, as long as they ensure that the active ingredients in the substitute are the same as those in the formulation prescribed. The inappropriateness of the term inert is becoming increasingly apparent as evidence of adverse reactions--some fatal--to excipients mounts. The likelihood that some "active" constituents, particularly erythromycin, have been blamed for such reactions deserves to be investigated. The public deserves to be better protected. For example, the United States has legislation requiring complete labelling of all food, drugs and cosmetics that incorporate more than one ingredient, no matter how innocuous the constituents are believed to be. In Canada, drug manufacturers are not even required to share this information with physicians or pharmacists when they introduce a new drug or reformulate a product already being marketed, nor are pharmacists required to disclose the contents of formulations that they prepare in the absence of commercially available products. PMID:6498699

  16. Assimilation of Satellite Ozone Observations

    NASA Technical Reports Server (NTRS)

    Stajner, I.; Winslow, N.; Wargan, K.; Hayashi, H.; Pawson, S.; Rood, R.

    2003-01-01

    This talk will discuss assimilation of ozone data from satellite-borne instruments. Satellite observations of ozone total columns and profiles have been measured by a series of Total Ozone Mapping Spectrometer (TOMS), Solar Backscatter Ultraviolet (SBUV) instruments, and more recently by the Global Ozone Monitoring Experiment. Additional profile data are provided by instruments on NASA's Upper Atmosphere Research Satellite and by occultation instruments on other platforms. Instruments on Envisat' and future EOS Aura satellite will supply even more comprehensive data about the ozone distribution. Satellite data contain a wealth of information, but they do not provide synoptic global maps of ozone fields. These maps can be obtained through assimilation of satellite data into global chemistry and transport models. In the ozone system at NASA's Data Assimilation Office (DAO) any combination of TOMS, SBUV, and Microwave Limb sounder (MLS) data can be assimilated. We found that the addition of MLS to SBUV and TOMS data in the system helps to constrain the ozone distribution, especially in the polar night region and in the tropics. The assimilated ozone distribution in the troposphere and lower stratosphere is sensitive also to finer changes in the SBUV and TOMS data selection and to changes in error covariance models. All results are established by comparisons of assimilated ozone with independent profiles from ozone sondes and occultation instruments.

  17. Volatilization of low vapor pressure--volatile organic compounds (LVP-VOCs) during three cleaning products-associated activities: Potential contributions to ozone formation.

    PubMed

    Shin, Hyeong-Moo; McKone, Thomas E; Bennett, Deborah H

    2016-06-01

    There have been many studies to reduce ozone formation mostly from volatile organic compound (VOC) sources. However, the role of low vapor pressure (LVP)-VOCs from consumer products remains mostly unexplored and unaddressed. This study explores the impact of high production volume LVP-VOCs on ozone formation from three cleaning products-associated activities (dishwashing, clothes washing, and surface cleaning). We develop a model framework to account for the portion available for ozone formation during the use phase and from the down-the-drain disposal. We apply experimental studies that measured emission rates or models that were developed for estimating emission rates of organic compounds during the use phase. Then, the fraction volatilized (fvolatilized) and the fraction disposed down the drain (fdown-the-drain) are multiplied by the portion available for ozone formation for releases to the outdoor air (fO3|volatilized) and down-the-drain (fO3|down-the-drain), respectively. Overall, for chemicals used in three specific cleaning-product uses, fvolatilized is less than 0.6% for all studied LVP-VOCs. Because greater than 99.4% of compounds are disposed of down the drain during the use phase, when combined with fO3|volatilized and fO3|down-the-drain, the portion available for ozone formation from the direct releases to outdoor air and the down-the-drain disposal is less than 0.4% and 0.2%, respectively. The results from this study indicate that the impact of the studied LVP-VOCs on ozone formation is very sensitive to what occurs during the use phase and suggest the need for future research on experimental work at the point of use. PMID:27016807

  18. Ozone Production in the Boston Urban Area and Transport Downwind: Computation from Lidar Measurements and Comparison with Air Quality Forecast Models

    NASA Astrophysics Data System (ADS)

    Hardesty, R. M.; Senff, C. J.; Alvarez, R. J.; Sandberg, S. P.; McKeen, S. A.; Wilczak, J. M.; Djalalova, I. V.; White, A. B.

    2005-12-01

    An important element in understanding and successfully forecasting local air quality events is accurate characterization of production of pollutants in urban regions and advection to areas downwind. During the 2004 New England Air Quality Study (NEAQS), which was conducted within the framework of the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) field experiment, NOAA deployed its airborne ozone and aerosol lidar to characterize the 3-dimensional structure of ozone and aerosol fields in the New England region. We have used the data set gathered with the lidar to compute ozone production in the Boston urban plume and to investigate transport and mixing processes for several days of the study. One of the few high ozone events in northern New England during the summer of 2004 occurred on July 30, when ozone levels exceeded 100 ppbv on Appledore Island just east of Portsmouth, NH. On this day, trajectories computed from wind profiler data showed that the New York plume was transported directly over Boston and then north-northeastwards along the New Hampshire and Maine coasts. By flying across the plume upstream and downwind of Boston and computing the horizontal ozone flux within the plume, we were able to estimate that the ozone flux downwind of Boston increased by 36 percent, concentrating the pollutants and likely playing a role in the high ozone observed. We also examined transport on August 3, when a shallow plume of high ozone was observed near Bar Harbor, ME. Trajectories indicated that this was a piece of the previous day's Boston plume, which was likely transported overnight across the Gulf of Maine in a very shallow layer. Later in the day, another plume was observed further south near Portland, ME. Trajectories showed that this was the Boston plume emitted on the morning of August 3, which followed a different transport path due to changes in the wind field over the period. On August 9, we mapped out the Boston

  19. Pilot experiments with electrodialysis and ozonation for the production of a fertiliser from urine.

    PubMed

    Pronk, W; Zuleeg, S; Lienert, J; Escher, B; Koller, M; Berner, A; Koch, G; Boller, M

    2007-01-01

    Pilot tests were performed with a process combination of electrodialysis and ozonation for the removal of micropollutants and the concentration of nutrients in urine. In continuous and batch experiments, maximum concentration factors up to 3.5 and 4.1 were obtained, respectively. The desalination capacity did not decrease significantly during continuous operation periods of several weeks. Membrane cleaning after 195 days resulted in approximately 35% increase in desalination rate. The Yeast Estrogen Screen (YES), a bioassay that selectively detects oestrogenic compounds, confirmed that about 90% of the oestrogenic activity was removed by electrodialysis. HPLC analysis showed that ibuprofen was removed to a high extent, while other micropollutants were below the detection limit. In view of the fact that ibuprofen is among the most rapidly transported micropollutants in electrodialysis processes, this result indicates that electrodialysis provides an effective barrier for micropollutants. Standardised plant growth tests were performed in the field with the salt solution resulting from the treatment by electrodialysis and subsequent ozonation. The results show that the plant height is comparable to synthetic fertilisers, but the crop yield is slightly lower. The latter is probably caused by volatilisation losses during field application, which can be prevented by improved application technologies. PMID:17881856

  20. Use of AIRS, OMI, MLS, and TES Data in Assessing Forest Ecosystem Exposure to Ozone

    NASA Technical Reports Server (NTRS)

    Spruce, Joseph P.

    2007-01-01

    Ground-level ozone at high levels poses health threats to exposed flora and fauna, including negative impacts to human health. While concern is common regarding depletion of ozone in the stratosphere, portions of the urban and rural United States periodically have high ambient levels of tropospheric ozone on the ground. Ozone pollution can cause a variety of impacts to susceptible vegetation (e.g., Ponderosa and Jeffrey pine species in the southwestern United States), such as stunted growth, alteration of growth form, needle or leaf chlorosis, and impaired ability to withstand drought-induced water stress. In addition, Southern Californian forests with high ozone exposures have been recently subject to multiyear droughts that have led to extensive forest overstory mortality from insect outbreaks and increased incidence of wildfires. Residual forests in these impacted areas may be more vulnerable to high ozone exposures and to other forest threats than ever before. NASA sensors collect a wealth of atmospheric data that have been used recently for mapping and monitoring regional tropospheric ozone levels. AIRS (Atmospheric Infrared Sounder), OMI (Ozone Monitoring Instrument), MLS (Microwave Limb Sounder), and TES (Tropospheric Emission Spectrometer) data could be used to assess forest ecosystem exposure to ozone. Such NASA data hold promise for providing better or at least complementary synoptic information on ground-level ozone levels that Federal agency partners can use to assess forest health trends and to mitigate the threats as needed in compliance with Federal laws and mandates. NASA data products on ozone concentrations may be able to aid applications of DSTs (decision support tools) adopted by the USDA FS (U.S. Department of Agriculture Forest Service) and by the NPS (National Park Service), such as the Ozone Calculator, in which ground ozone estimates are employed to assess ozone impacts to forested vegetation.

  1. 17 CFR 41.25 - Additional conditions for trading for security futures products.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... trading for security futures products. 41.25 Section 41.25 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION SECURITY FUTURES PRODUCTS Requirements and Standards for Listing Security Futures Products § 41.25 Additional conditions for trading for security futures products. (a)...

  2. Summary of aircraft results for 1978 southeastern Virginia urban plume measurement study of ozone, nitrogen oxides, and methane

    NASA Technical Reports Server (NTRS)

    Gregory, G. L.; Wornom, D. E.; Mathis, J. J., Jr.; Sebacher, D. I.

    1980-01-01

    Ozone production was determined from aircraft and surface in situ measurements, as well as from an airborne laser absorption spectrometer. Three aircraft and approximately 10 surface stations provided air-quality data. Extensive meteorological, mixing-layer-height, and ozone-precursor data were also measured. Approximately 50 hrs (9 flight days) of data from the aircraft equipped to monitor ozone, nitrogen oxides, dewpoint temperature, and temperature are presented. In addition, each experiment conducted is discussed.

  3. Ozone-Initiated Chemistry in an Occupied Simulated AircraftCabin

    SciTech Connect

    Weschler, C.J.; Wisthaler, A.; Cowlind, S.; Tamas, G.; Strom-Tejsena, P.; Hodgson, A.T.; Destaillats, H.; Herrington, J.; Zhang,J.; Nazaroff, W.W.

    2007-07-01

    We have used multiple analytical methods to characterize the gas-phase products formed when ozone was added to cabin air during simulated 4-hour flights that were conducted in a reconstructed section of a B-767 aircraft containing human occupants. Two separate groups of 16 females were each exposed to four conditions: low air exchange (4.4 h-1), <2 ppb ozone; low air exchange, 61-64 ppb ozone; high air exchange (8.8 h-1), <2 ppb ozone; and high air exchange, 73-77 ppb ozone. The addition of ozone to the cabin air increased the levels of identified byproducts from {approx}70 to 130 ppb at the lower air exchange rate and from {approx}30 to 70 ppb at the higher air exchange rate. Most of the increase was attributable to acetone, nonanal, decanal, 4-oxopentanal (4-OPA), 6-methyl-5-hepten-2-one (6-MHO), formic acid, and acetic acid, with 0.25-0.30 mol of quantified product volatilized per mol of ozone consumed. Several of these compounds reached levels above their reported odor thresholds. Most byproducts were derived from surface reactions with occupants and their clothing, consistent with the inference that occupants were responsible for the removal of >55% of the ozone in the cabin. The observations made in this study have implications for other indoor settings. Whenever human beings and ozone are simultaneously present, one anticipates production of acetone, nonanal, decanal, 6-MHO, geranyl acetone, and 4-OPA.

  4. Self-enhanced ozonation of benzoic acid at acidic pHs.

    PubMed

    Huang, Xianfeng; Li, Xuchun; Pan, Bingcai; Li, Hongchao; Zhang, Yanyang; Xie, Bihuang

    2015-04-15

    Ozonation of recalcitrant contaminants under acidic conditions is inefficient due to the lack of initiator (e.g., OH(-)) for ozone to produce hydroxyl radicals (HO). In this study, we reported that benzoic acid (BA), which is inert to ozone attack, underwent efficient degradation by ozone at acidic pH (2.3). The kinetics of BA degradation and ozone decomposition were both enhanced by increasing BA concentrations. Essentially, it is a HO-mediated reaction. Based on the exclusion of possible contributions of H2O2 and phenol-like intermediates for HO production, the reaction mechanism involved the formation of ozone ion ( [Formula: see text] ), which is an effective precursor of HO, was thus proposed. The hydroxycyclohexadienyl-type radicals generated during the attack of BA by HO may lead to the formation of [Formula: see text] . Meanwhile, [Formula: see text] could also be possibly formed from the reaction between ozone and organic (e.g., ROO∙) or inorganic peroxyl radicals (e.g., HO2). In addition, the hydroxylated products like phenol-like intermediates also played a positive role in HO production. Consequently, HO was produced efficiently under acidic conditions, resulting in rapid degradation of BA. This study provides a new approach for ozone activation even at acidic pHs, and broadens the knowledge of ozonation in removal of micropollutants from water. PMID:25635752

  5. Oxidation of bisphenol A by ozone in aqueous solution.

    PubMed

    Deborde, Marie; Rabouan, Sylvie; Mazellier, Patrick; Duguet, Jean-Pierre; Legube, Bernard

    2008-10-01

    Based on the literature data, an efficient removal of bisphenol A (BPA) during ozonation can be expected under water treatment conditions. However, up to now, the degradation products have not been identified. This has been the main point of this study. Aqueous solutions of BPA have been analyzed by LC-UV, LC-MS or MS/MS at different ozone doses. Under our experimental conditions, up to five major transformation products were evidenced. According to UV, MS and MS/MS spectra characteristics, chemical structures are consistent with catechol, orthoquinone, muconic acid derivatives of BPA, benzoquinone and 2-(4-hydroxyphenyl)-propan-2-ol. Moreover, three additional minor transformation products have been observed for which chemical structures have been tentatively proposed. In the case of major transformation products, the reaction pathway may involve an initial ozone reaction by electrophilic substitution or 1,3-dipolar cycloaddition. In the presence of ozone, these primary transformation products were shown to be unstable. Further transformation products, with smaller molecular weight and more polar character such as aliphatic acids or aldehydes, are then expected during ozonation. The identification of minor transformation products was more complex to assess. However, oligomeric structures have been evidenced, certainly arising from secondary reaction between various oxidation products of BPA. The formation of these latter products would not be favored under water treatment conditions. PMID:18752822

  6. 40 CFR Appendix H to Subpart A of... - Clean Air Act Amendments of 1990 Phaseout Schedule for Production of Ozone-Depleting Substances

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 18 2013-07-01 2013-07-01 false Clean Air Act Amendments of 1990... 82—Clean Air Act Amendments of 1990 Phaseout Schedule for Production of Ozone-Depleting Substances... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION...

  7. 40 CFR Appendix H to Subpart A of... - Clean Air Act Amendments of 1990 Phaseout Schedule for Production of Ozone-Depleting Substances

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 false Clean Air Act Amendments of 1990... 82—Clean Air Act Amendments of 1990 Phaseout Schedule for Production of Ozone-Depleting Substances... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION...

  8. 40 CFR Appendix H to Subpart A of... - Clean Air Act Amendments of 1990 Phaseout Schedule for Production of Ozone-Depleting Substances

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 18 2014-07-01 2014-07-01 false Clean Air Act Amendments of 1990... 82—Clean Air Act Amendments of 1990 Phaseout Schedule for Production of Ozone-Depleting Substances... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION...

  9. Enhanced Ozone Production at Low Temperatures due to Ethanol (E85)

    NASA Astrophysics Data System (ADS)

    Ginnebaugh, D. L.; Livingstone, P. L.; Jacobson, M. Z.

    2009-12-01

    The increased use of ethanol in transportation fuels warrants an investigation of its consequences. An important component of such an investigation is the temperature-dependence of ethanol and gasoline exhaust chemistry. We use the near-explicit Master Chemical Mechanism (MCM, version 3.1, LEEDS University) with the SMVGEAR II chemical ordinary differential solver to provide the speed necessary to simulate explicit chemistry to examine such effects. The MCM has over 13,500 organic reactions and 4,600 species. SMVGEAR II is a sparse-matrix Gear solver that reduces the computation time significantly while maintaining any specified accuracy. Although for this study we use a box model, we determined that the speed of the MCM with the SMVGEAR solver will allow the MCM to be modeled in 3-dimensions. We also verified the accuracy of the model with comparisons to smog chamber data. We use species-resolved tailpipe emissions data for E85 (15% gasoline, 85% ethanol fuel blend) and gasoline vehicles to compare the impact of each on ozone and carcinogenic organic gases as a function of ambient temperature and background concentrations, using Los Angeles in 2020 as a base case. We use two different emissions sets - one is a compilation of data taken at near 24 C and the other from data taken at -7 C - to determine how atmospheric chemistry and emissions are affected by temperature. We include diurnal effects by examining 2 day and 5 day scenarios. We find that for both emission data sets, the average ozone concentrations through the range of temperatures tested are higher with E85 than with gasoline by 8 parts per billion volume (ppbv) at higher temperatures to 55 ppbv at low temperatures and low sunlight (winter conditions) for an area with a high nitrogen oxides (NOx) to non-methane organic gases (NMOG) ratio. The results suggest that E85's effect on health through ozone formation becomes increasingly more significant relative to gasoline as temperatures decreased due to the

  10. Ozone-induced stomatal sluggishness changes carbon and water balance of temperate deciduous forests

    NASA Astrophysics Data System (ADS)

    Hoshika, Yasutomo; Katata, Genki; Deushi, Makoto; Watanabe, Makoto; Koike, Takayoshi; Paoletti, Elena

    2015-05-01

    Tropospheric ozone concentrations have increased by 60-100% in the Northern Hemisphere since the 19th century. The phytotoxic nature of ozone can impair forest productivity. In addition, ozone affects stomatal functions, by both favoring stomatal closure and impairing stomatal control. Ozone-induced stomatal sluggishness, i.e., a delay in stomatal responses to fluctuating stimuli, has the potential to change the carbon and water balance of forests. This effect has to be included in models for ozone risk assessment. Here we examine the effects of ozone-induced stomatal sluggishness on carbon assimilation and transpiration of temperate deciduous forests in the Northern Hemisphere in 2006-2009 by combining a detailed multi-layer land surface model and a global atmospheric chemistry model. An analysis of results by ozone FACE (Free-Air Controlled Exposure) experiments suggested that ozone-induced stomatal sluggishness can be incorporated into modelling based on a simple parameter (gmin, minimum stomatal conductance) which is used in the coupled photosynthesis-stomatal model. Our simulation showed that ozone can decrease water use efficiency, i.e., the ratio of net CO2 assimilation to transpiration, of temperate deciduous forests up to 20% when ozone-induced stomatal sluggishness is considered, and up to only 5% when the stomatal sluggishness is neglected.

  11. The Safety and Anti-Tumor Effects of Ozonated Water in Vivo

    PubMed Central

    Kuroda, Kohei; Azuma, Kazuo; Mori, Takuro; Kawamoto, Kinya; Murahata, Yusuke; Tsuka, Takeshi; Osaki, Tomohiro; Ito, Norihiko; Imagawa, Tomohiro; Itoh, Fumio; Okamoto, Yoshiharu

    2015-01-01

    Ozonated water is easier to handle than ozone gas. However, there have been no previous reports on the biological effects of ozonated water. We conducted a study on the safety of ozonated water and its anti-tumor effects using a tumor-bearing mouse model and normal controls. Local administration of ozonated water (208 mM) was not associated with any detrimental effects in normal tissues. On the other hand, local administration of ozonated water (20.8, 41.6, 104, or 208 mM) directly into the tumor tissue induced necrosis and inhibited proliferation of tumor cells. There was no significant difference in the number of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labeling (TUNEL)-positive cells following administration of ozonated water. The size of the necrotic areas was dependent on the concentration of ozonated water. These results indicate that ozonated water does not affect normal tissue and damages only the tumor tissue by selectively inducing necrosis. There is a possibility that it exerts through the production of reaction oxygen species (ROS). In addition, the induction of necrosis rather than apoptosis is very useful in tumor immunity. Based on these results, we believe that administration of ozonated water is a safe and potentially simple adjunct or alternative to existing antineoplastic treatments. PMID:26506343

  12. Ozone-induced stomatal sluggishness changes carbon and water balance of temperate deciduous forests

    PubMed Central

    Hoshika, Yasutomo; Katata, Genki; Deushi, Makoto; Watanabe, Makoto; Koike, Takayoshi; Paoletti, Elena

    2015-01-01

    Tropospheric ozone concentrations have increased by 60–100% in the Northern Hemisphere since the 19th century. The phytotoxic nature of ozone can impair forest productivity. In addition, ozone affects stomatal functions, by both favoring stomatal closure and impairing stomatal control. Ozone-induced stomatal sluggishness, i.e., a delay in stomatal responses to fluctuating stimuli, has the potential to change the carbon and water balance of forests. This effect has to be included in models for ozone risk assessment. Here we examine the effects of ozone-induced stomatal sluggishness on carbon assimilation and transpiration of temperate deciduous forests in the Northern Hemisphere in 2006-2009 by combining a detailed multi-layer land surface model and a global atmospheric chemistry model. An analysis of results by ozone FACE (Free-Air Controlled Exposure) experiments suggested that ozone-induced stomatal sluggishness can be incorporated into modelling based on a simple parameter (gmin, minimum stomatal conductance) which is used in the coupled photosynthesis-stomatal model. Our simulation showed that ozone can decrease water use efficiency, i.e., the ratio of net CO2 assimilation to transpiration, of temperate deciduous forests up to 20% when ozone-induced stomatal sluggishness is considered, and up to only 5% when the stomatal sluggishness is neglected. PMID:25943276

  13. Ozone-induced stomatal sluggishness changes carbon and water balance of temperate deciduous forests.

    PubMed

    Hoshika, Yasutomo; Katata, Genki; Deushi, Makoto; Watanabe, Makoto; Koike, Takayoshi; Paoletti, Elena

    2015-01-01

    Tropospheric ozone concentrations have increased by 60-100% in the Northern Hemisphere since the 19(th) century. The phytotoxic nature of ozone can impair forest productivity. In addition, ozone affects stomatal functions, by both favoring stomatal closure and impairing stomatal control. Ozone-induced stomatal sluggishness, i.e., a delay in stomatal responses to fluctuating stimuli, has the potential to change the carbon and water balance of forests. This effect has to be included in models for ozone risk assessment. Here we examine the effects of ozone-induced stomatal sluggishness on carbon assimilation and transpiration of temperate deciduous forests in the Northern Hemisphere in 2006-2009 by combining a detailed multi-layer land surface model and a global atmospheric chemistry model. An analysis of results by ozone FACE (Free-Air Controlled Exposure) experiments suggested that ozone-induced stomatal sluggishness can be incorporated into modelling based on a simple parameter (gmin, minimum stomatal conductance) which is used in the coupled photosynthesis-stomatal model. Our simulation showed that ozone can decrease water use efficiency, i.e., the ratio of net CO2 assimilation to transpiration, of temperate deciduous forests up to 20% when ozone-induced stomatal sluggishness is considered, and up to only 5% when the stomatal sluggishness is neglected. PMID:25943276

  14. Comparison of formation of disinfection by-products by chlorination and ozonation of wastewater effluents and their toxicity to Daphnia magna.

    PubMed

    Park, Keun-Young; Choi, Su-Young; Lee, Seung-Hoon; Kweon, Ji-Hyang; Song, Ji-Hyeon

    2016-08-01

    This study compared the two most frequently used disinfectants (i.e., chlorine and ozone) to understand their efficiency in wastewater effluents and the ecotoxicity of disinfection by-products created during chlorination and ozonation. Four trihalomethanes (THMs) and nine haloacetic acids (HAAs) were measured from a chlorine-disinfected sample and two aldehydes (i.e., formaldehydes and acetaldehydes) were analyzed after ozonation. Chlorination was effective for total coliform removal with Ct value in the range of 30-60 mg-min/L. Over 1.6 mg/L of ozone dose and 0.5 min of the contact time presented sufficient disinfection efficiency. The concentration of THMs increased with longer contact time (24 h), but that of HAAs showed little change with contact time. The measured concentration of formaldehyde at the ozone dose of 1.6 mg/L and the contact time of 9 min showed the greatest value in this study, approximately 330 μg L(-1), from which the corresponding ecotoxicity was determined using an indicator species, Daphnia magna. The ecotoxicity results were consistent with the toxicological features judged by occurrence, genotoxicity, and carcinogenicity. Both the disinfection efficiency as well as the DBP formation potential should therefore be considered to avoid harmful impacts on aquatic environments when a disinfection method is used for wastewater effluents. PMID:27213572

  15. The use of ozone during advanced primary treatment of wastewater for its reuse in agriculture: an approach to enhance coagulation, disinfection and crop productivities.

    PubMed

    Campos-Reales-Pineda, A E; Orta de Velásquez, M T; Rojas-Valencia, M N

    2008-01-01

    The purpose of this work was to evaluate the effect that ozone (O(3)) has on the advanced primary treatment (APT) and disinfection of wastewaters for their reuse in agriculture. The enhancement and optimization of APT was done by applying low O(3) doses during coagulation. By applying an ozone dose of 2 mg/L during APT, the required coagulant dose may be reduced by up to 25% to achieve a similar turbidity removal (and up to 50% for total suspended solids removal), when compared to a conventional APT treatment. When the same coagulant dose was applied (60 mg/L), the volume of settleable solids was reduced from 31.0 to 25.5 mL/L, and the settling velocity increased from 0.111 to 0.139 m/min. Disinfection was also improved by the use of ozone, which leads to better plant germination rates than when using chlorination, because of reduced toxicity of the ozonated effluents. Additionally, helminth eggs content was reduced by applying ozone. PMID:18413959

  16. Application of ozone for enhancing the microbiological safety and quality of foods: a review.

    PubMed

    Kim, J G; Yousef, A E; Dave, S

    1999-09-01

    Ozone (O3) is a strong antimicrobial agent with numerous potential applications in the food industry. High reactivity, penetrability, and spontaneous decomposition to a nontoxic product (i.e., O2) make ozone a viable disinfectant for ensuring the microbiological safety of food products. Ozone has been used for decades in many countries and recently, the generally recognized as safe (GRAS) status of this gas has been reaffirmed in the United States. Ozone, in the gaseous or aqueous phases, is effective against the majority of microorganisms tested by numerous research groups. Relatively low concentrations of ozone and short contact time are sufficient to inactivate bacteria, molds, yeasts, parasites, and viruses. However, rates of inactivation are greater in ozone demand-free systems than when the medium contains oxidizable organic substances. Susceptibility of microorganisms to ozone also varies with the physiological state of the culture, pH of the medium, temperature, humidity, and presence of additives (e.g., acids, surfactants, and sugars). Ozone applications in the food industry are mostly related to decontamination of product surface and water treatment. Ozone has been used with mixed success to inactivate contaminant microflora on meat, poultry, eggs, fish, fruits, vegetables, and dry foods. The gas also is useful in detoxification and elimination of mycotoxins and pesticide residues from some agricultural products. Excessive use of ozone, however, may cause oxidation of some ingredients on food surface. This usually results in discoloration and deterioration of food flavor. Additional research is needed to elucidate the kinetics and mechanisms of microbial inactivation by ozone and to optimize its use in food applications. PMID:10492485

  17. 39 CFR 3055.6 - Addition of new market dominant products or changes to existing market dominant products.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 39 Postal Service 1 2012-07-01 2012-07-01 false Addition of new market dominant products or changes to existing market dominant products. 3055.6 Section 3055.6 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Annual Reporting of Service Performance Achievements § 3055.6 Addition of...

  18. Corona Discharge Influences Ozone Concentrations Near Rats

    SciTech Connect

    Goheen, Steven C.; Gaither, Kari A.; Anantatmula, Shantha M.; Mong, Gary M.; Sasser, Lyle B.; Lessor, Delbert L.

    2004-02-26

    Ozone is produced by corona discharge in air. Its production is enhanced near grounded water. Whether grounded animals behave like grounded water, producing more ozone was investigated. Rats were exposed to corona discharge in a plastic cage. The concentration of ozone in the gas phase was monitored. The ozone concentration exceeded ambient levels only in the presence of corona discharge and either rats or water. When water or rats were exposed to corona discharge, ozone levels were more than 10 times higher than controls. Ozone levels increased rapidly with applied voltage. There was also a correlation between the distance of the corona needle to the rats and the amount of ozone produced. As the distance increased, ozone production decreased. These results are discussed in relation to the potential exposure of mammals to ozone in the vicinity of corona discharge and electric fields.

  19. Regional Transport Versus Local Production of Ground Level Tropospheric Ozone in the Baltimore Region: a Statistical Analysis

    NASA Astrophysics Data System (ADS)

    Hudson, R. D.; Nguyen, D.

    2006-05-01

    Significant levels of ozone in the lowest 2000 m of the atmosphere, often above the planetary boundary layer, have been measured from aircraft flights over the eastern US. These elevated amounts of ozone can be mixed down to the ground as the nocturnal inversion breaks down at about 10.00 am. We have observed this downward insertion of ozone in the daily ground based measurements made by the Maryland Department of the Environment. There is a strong correlation between the amount of ozone brought down and the direction of the winds above the boundary layer, agreeing with previous studies of regional transport. The ozone data from seven measurement sites in the Baltimore region over the period 1994 to 2005 has been examined. There is a distinct change in the amount of ozone mixed down between 2002 and 2003. The implications of the results of the analysis to local pollution controls will be discussed.

  20. Prophylaxis and therapeutic potential of ozone in buiatrics: Current knowledge.

    PubMed

    Đuričić, Dražen; Valpotić, Hrvoje; Samardžija, Marko

    2015-08-01

    Ozone therapy has been in use since 1896 in the USA. As a highly reactive molecule, ozone may inactivate bacteria, viruses, fungi, yeasts and protozoans, stimulate the oxygen metabolism of tissue, treat diseases, activate the immune system, and exhibit strong analgesic activity. More recently, ozone has been used in veterinary medicine, particularly in buiatrics, but still insufficiently. Medical ozone therapy has shown effectiveness as an alternative to the use of antibiotics, which are restricted to clinical use and have been withdrawn from non-clinical use as in-feed growth promoters in animal production. This review is an overview of current knowledge regarding the preventive and therapeutic effects of ozone in ruminants for the treatment of puerperal diseases and improvement in their fertility. In particular, ozone preparations have been tested in the treatment of reproductive tract lesions, urovagina and pneumomovagina, metritis, endometritis, fetal membrane retention and mastitis, as well as in the functional restoration of endometrium in dairy cows and goats. In addition, the preventive use of the intrauterine application of ozone has been assessed in order to evaluate its effectiveness in improving reproductive efficiency in dairy cows. No adverse effects were observed in cows and goats treated with ozone preparations. Moreover, there is a lot of evidence indicating the advantages of ozone preparation therapy in comparison to the application of antibiotics. However, there are certain limitations on ozone use in veterinary medicine and buiatrics, such as inactivity against intracellular microbes and selective activity against the same bacterial species, as well as the induction of tissue inflammation through inappropriate application of the preparation. PMID:26059777

  1. Reaction products of amido-amine and epoxide useful as fuel additives

    SciTech Connect

    Efner, H.F.

    1988-04-12

    A method for reducing engine deposits in an internal combustion engine is described comprising the addition of a detergent fuel additive package to a hydrocarbon fuel for the engine. The fuel detergent is added in an amount effective to reduce deposits and the hydrocarbon fuel is used with detergent additive as fuel in an internal combustion engine. The detergent fuel additive package comprises: (1) a fuel detergent additive that is the reaction product prepared by reacting (a) vegetable oil or (b) higher carboxylic acid chosen from (i) aliphatic fatty acids having 10-25 carbon atoms and (ii) aralkyl acids having 12-42 carbon atoms with (c) multiamine to obtain a fist product mixture with the first product mixture reacted with alklylene oxide to produce a second product mixture and (2) a fuel detergent additive solvent compatible with the fuels.

  2. Ozonation of pyridine and other N-heterocyclic aromatic compounds: Kinetics, stoichiometry, identification of products and elucidation of pathways.

    PubMed

    Tekle-Röttering, Agnes; Reisz, Erika; Jewell, Kevin S; Lutze, Holger V; Ternes, Thomas A; Schmidt, Winfried; Schmidt, Torsten C

    2016-10-01

    Pyridine, pyridazine, pyrimidine and pyrazine were investigated in their reaction with ozone. These compounds are archetypes for heterocyclic aromatic amines, a structural unit that is often present in pharmaceuticals, pesticides and dyestuffs (e.g., enoxacin, pyrazineamide or pyrimethamine). The investigated target compounds react with ozone with rate constants ranging from 0.37 to 57 M(-1) s(-1), hampering their degradation during ozonation. In OH radical scavenged systems the reaction of ozone with pyridine and pyridazine is characterized by high transformation (per ozone consumed) of 55 and 54%, respectively. In non scavenged system the transformation drops to 52 and 12%, respectively. However, in the reaction of pyrimidine and pyrazine with ozone this is reversed. Here, in an OH radical scavenged system the compound transformation is much lower (2.1 and 14%, respectively) than in non scavenged one (22 and 25%, respectively). This is confirmed by corresponding high N-oxide formation in the ozonation of pyridine and pyridazine, but probably low formation in the reaction of pyrimidine and pyrazine with ozone. With respect to reaction mechanisms, it is suggested that ozone adduct formation at nitrogen is the primary step in the ozonation of pyridine and pyridazine. On the contrary, ozone adduct formation to the aromatic ring seems to occur especially in the ozonation of pyrimidine as inferred from hydrogen peroxide yield. However, also OH radical reactions are supposed processes in the case of pyrimidine and in particular for pyrazine, albeit negligible OH radical yields are obtained. The low compound transformation in OH radical scavenged system can prove this. As a result of negligible OH radical yields in all cases (less than 6%) electron transfer as primary reaction pathway plays a subordinate role. PMID:27448509

  3. Quantification of Methane and VOC Emissions from Natural Gas Production in Two Basins with High Ozone Events

    NASA Astrophysics Data System (ADS)

    Edie, R.; Robertson, A.; Snare, D.; Soltis, J.; Field, R. A.; Murphy, S. M.

    2015-12-01

    Since 2005, the Uintah Basin of Utah and the Upper Green River Basin of Wyoming frequently exceeded the EPA 8-hour allowable ozone level of 75 ppb, spurring interest in volatile organic compounds (VOCs) emitted during oil and gas production. Debate continues over which stage of production (drilling, flowback, normal production, transmission, etc.) is the most prevalent VOC source. In this study, we quantify emissions from normal production on well pads by using the EPA-developed Other Test Method 33a. This methodology combines ground-based measurements of fugitive emissions with 3-D wind data to calculate the methane and VOC emission fluxes from a point source. VOC fluxes are traditionally estimated by gathering a canister of air during a methane flux measurement. The methane:VOC ratio of this canister is determined at a later time in the laboratory, and applied to the known methane flux. The University of Wyoming Mobile Laboratory platform is equipped with a Picarro methane analyzer and an Ionicon Proton Transfer Reaction-Time of Flight-Mass Spectrometer, which provide real-time methane and VOC data for each well pad. This independent measurement of methane and VOCs in situ reveals multiple emission sources on one well pad, with varying methane:VOC ratios. Well pad emission estimates of methane, benzene, toluene and xylene for the two basins will be presented. The different emission source VOC profiles and the limitations of real-time and traditional VOC measurement methods will also be discussed.

  4. USE OF QUANTITATIVE TWO-DIMENSIONAL GEL ELECTROPHORESIS TO ANALYZE CHANGES IN ALVEOLAR MACROPHAGE PROTEINS IN HUMANS EXPOSED TO OZONE

    EPA Science Inventory

    Acute exposure of humans to 0.4 ppm ozone is known to cause production of components which mediate inflammation and damage in the lung. he contribution of alveolar macrophages to this process is not well understood. n addition, ozone may cause more extensive cellular changes than...

  5. Reactions of ozone with. alpha. -pinene and. beta. -pinene in air: Yields of gaseous and particulate products

    SciTech Connect

    Hatakeyama, S.; Izumi, K.; Fukuyama, T.; Akimoto, H. )

    1989-09-20

    Reactions of ozone with {alpha}-prinene and {beta}-pinene were studied for the purpose of obtaining the quantitative yields of gaseous and particulate products. Major gaseous products from {alpha}-pinene were CO, CO{sub 2}, HCHO, and aldehydes mainly composed of pinonaldehyde and nor-pinonaldehyde, while those from {beta}-pinene were CO{sub 2}, HCHO, and 6,6-dimethylbicyclo(3.1.1)heptan-2-one. Average molar yields from {alpha}-pinene were CO; 9{plus minus}1%, CO{sub 2}; 30{plus minus}2%, HCHO; 22{plus minus}1%, and aldehydes; 51{plus minus}6%. Average molar yields from {beta}-pinene were CO{sub 2}; 27{plus minus}2%, HCHO; 76{plus minus}2%, and 6,6-dimethylbicyclo(3.1.1)heptan-2-one; 40{plus minus}2%. Particulate products were found to include pinonaldehyde, nor-pinonaldehyde, pinonic acid, and nor-pinonic acid from {alpha}-pinene. The yields of the particulate aldehydes decreased with the reaction time, whereas the yields of the acids increased. This observation suggests the sequential oxidation of aldehydes to carboxylic acids. From {beta}-pinene, only 6,6-dimethylbicyclo(3.1.1)heptan-2-one was identified as a particulate product. For {alpha}-pinene, most of the products are explainable in terms of the reaction mechanism similar to that for the cyclohexene/ozone reaction, whereas for {beta}-pinene the principal reaction path is that of the doubly substituted Criegee intermediate. The total yields of organic aerosols from both {alpha}- and {beta}-pinene were measured with their concentrations at a lower ppb level. The yields were found almost constant in a pinene concentration range from 10 up to 100 ppb, being 18.3{plus minus}1.1 and 13.8{plus minus}0.8% for {alpha}- and {beta}-pinene, respectively, which are much lower than the previously reported values. {copyright} American Geophysical Union 1989

  6. Observation of ozone enhancement in the lower troposphere over East Asia from a space-borne ultraviolet spectrometer

    NASA Astrophysics Data System (ADS)

    Hayashida, S.; Liu, X.; Ono, A.; Yang, K.; Chance, K.

    2015-01-01

    We report observations from space using ultraviolet (UV) radiance for significant enhancement of ozone in the lower troposphere over Central and Eastern China (CEC). The recent retrieval products of the Ozone Monitoring Instrument (OMI) onboard the Earth Observing System (EOS)/Aura satellite revealed the spatial and temporal variation of ozone distributions in multiple layers in the troposphere. We compared the OMI-derived ozone over Beijing with airborne measurements by the Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft (MOZAIC) program. The correlation between OMI and MOZAIC ozone in the lower troposphere was reasonable, which assured the reliability of OMI ozone retrievals in the lower troposphere under enhanced ozone conditions. The ozone enhancement was clearly observed over CEC, with Shandong Province as its center, and most notable in June in any given year. Similar seasonal variations were observed throughout the nine-year OMI measurement period of 2005 to 2013. The ozone enhancement in June was associated with the enhancement of carbon monoxide (CO) and hotspots, which is consistent with previous studies of in-situ measurements such those made by the MTX2006 campaign. A considerable part of this ozone enhancement could be attributed to the emissions of ozone precursors from open crop residue burning (OCRB) after the winter wheat harvest, in addition to emissions from industrial activities and automobiles. The ozone distribution presented in this study is also consistent with some model studies that apply emissions from OCRB. The lower tropospheric ozone distribution is first shown from OMI retrieval in this study, and the results will be useful in clarifying any unknown factors that influence ozone distribution by comparison with model simulations.

  7. Ozone photolysis of paracetamol in aqueous solution.

    PubMed

    Neamţu, Mariana; Bobu, Maria; Kettrup, Antonius; Siminiceanu, Ilie

    2013-01-01

    The degradation of a paracetamol (N-acetil-para-aminofenol) aqueous solution (C (0) P = 5 mmol L(-1)) is studied in a bench-scale setup by means of simple ozonation (O3) and ozonation catalyzed with UV light (O3/UV) in order to quantify the influence of UV light on the degradation process. The results have shown that under the adopted experimental conditions (25°C, applied ozone dose = 9.8 mg L(-1) and gas flow rate of 20 L h(-1)) both oxidative systems are capable of removing the substrate with mineralization degrees up to 51% for ozonation and 53% for O3/UV. HPICE chromatography allowed the detection of nitrate ions and maleic and oxalic acids as ultimate carboxylic acids. The experimental data have been interpreted through 5 indicators: the conversion of paracetamol (XP ), the conversion degree of TOC (XTOC ), the apparent rate constant (kap ), the Hatta number (Ha) and the enhancement factor (E). The main advantage of photo-ozonation compared to simple ozonation was a more advanced conversion (79% vs. 92% after 90 min). The paracetamol decay follows a pseudo-first-order reaction with a superior rate constant (higher by 54%) for the UV catalyzed system in comparison with direct ozonation. Mineralization is slightly accelerated (+4%) in the O3/UV system, due to the additional production of hydroxyl radicals induced by the UV light and a higher Hatta number (+24%). Nevertheless, the process was still in the slow reaction kinetic regime (Ha < 0.3), and the enhancement factor was not significantly increased. The results are useful for the design and scale-up of the gas-liquid processes. PMID:23647117

  8. Stratospheric ozone depletion

    PubMed Central

    Rowland, F. Sherwood

    2006-01-01

    Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within the ozone layer have been shown to include very efficient catalytic chain reactions involving the chemical species HO, HO2, NO, NO2, Cl and ClO. The NOX and ClOX chains involve the emission at Earth's surface of stable molecules in very low concentration (N2O, CCl2F2, CCl3F, etc.) which wander in the atmosphere for as long as a century before absorbing ultraviolet radiation and decomposing to create NO and Cl in the middle of the stratospheric ozone layer. The growing emissions of synthetic chlorofluorocarbon molecules cause a significant diminution in the ozone content of the stratosphere, with the result that more solar ultraviolet-B radiation (290–320 nm wavelength) reaches the surface. This ozone loss occurs in the temperate zone latitudes in all seasons, and especially drastically since the early 1980s in the south polar springtime—the ‘Antarctic ozone hole’. The chemical reactions causing this ozone depletion are primarily based on atomic Cl and ClO, the product of its reaction with ozone. The further manufacture of chlorofluorocarbons has been banned by the 1992 revisions of the 1987 Montreal Protocol of the United Nations. Atmospheric measurements have confirmed that the Protocol has been very successful in reducing further emissions of these molecules. Recovery of the stratosphere to the ozone conditions of the 1950s will occur slowly over the rest of the twenty-first century because of the long lifetime of the precursor molecules. PMID:16627294

  9. Stratospheric ozone depletion.

    PubMed

    Rowland, F Sherwood

    2006-05-29

    Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within the ozone layer have been shown to include very efficient catalytic chain reactions involving the chemical species HO, HO2, NO, NO2, Cl and ClO. The NOX and ClOX chains involve the emission at Earth's surface of stable molecules in very low concentration (N2O, CCl2F2, CCl3F, etc.) which wander in the atmosphere for as long as a century before absorbing ultraviolet radiation and decomposing to create NO and Cl in the middle of the stratospheric ozone layer. The growing emissions of synthetic chlorofluorocarbon molecules cause a significant diminution in the ozone content of the stratosphere, with the result that more solar ultraviolet-B radiation (290-320 nm wavelength) reaches the surface. This ozone loss occurs in the temperate zone latitudes in all seasons, and especially drastically since the early 1980s in the south polar springtime-the 'Antarctic ozone hole'. The chemical reactions causing this ozone depletion are primarily based on atomic Cl and ClO, the product of its reaction with ozone. The further manufacture of chlorofluorocarbons has been banned by the 1992 revisions of the 1987 Montreal Protocol of the United Nations. Atmospheric measurements have confirmed that the Protocol has been very successful in reducing further emissions of these molecules. Recovery of the stratosphere to the ozone conditions of the 1950s will occur slowly over the rest of the twenty-first century because of the long lifetime of the precursor molecules. PMID:16627294

  10. A general circulation model simulation of the springtime Antarctic ozone decrease and its impact on mid-latitudes

    SciTech Connect

    Cariolle, D.; Lasserre-Bigorry, A.; Royer, J.F. ); Geleyn, J.F. )

    1990-02-20

    Ozone is treated as an interactive variable calculated by means of a continuity equation which takes account of advection and photochemical production and loss. The ozone concentration is also used to compute the heating and cooling rates due to the absorption of solar ultraviolet radiation, and the infrared emission in the stratosphere. The daytime ozone decrease due to the perturbed chlorine chemistry found at high southern latitudes is introduced as an extra loss in the ozone continuity equation. Results of the perturbed simulation show a very good agreement with the ozone measurements made during spring 1987. The simulation also shows the development of a high-latitude anomalous circulation, with a warming of the upper stratosphere resulting mainly from dynamical heating. In addition, a substantial ozone decrease is found at mid-latitudes in a thin stratospheric layer located between the 390 and the 470 K {theta} surfaces. A significant residual ozone decrease is found at the end of the model integration, 7 months after the final warming and the vortex breakdown. If there is a significant residual ozone decrease in the atmosphere, the ozone trends predicted by photochemical models which do not take into account the high-latitude perturbed chemistry are clearly inadequate. Finally, it is concluded that further model simulations at higher horizontal resolution, possibly with a better representation of the heterogeneous chemistry, will be needed to evaluate with more confidence the magnitude of the mid-latitudinal ozone depletion induced by the ozone hole formation.

  11. Differential chemical profiling to identify ozonation by-products of estrone-sulfate and first characterization of estrogenicity in generated drinking water.

    PubMed

    Bourgin, Marc; Gervais, Gaël; Bichon, Emmanuelle; Antignac, Jean-Philippe; Monteau, Fabrice; Leroy, Gaëla; Barritaud, Lauriane; Chachignon, Mathilde; Ingrand, Valérie; Roche, Pascal; Le Bizec, Bruno

    2013-07-01

    For a few years, the concern of water treatment companies is not only focused on the removal of target micropollutants but has been extended to the investigation of potential biologically active by-products generated during the treatment processes. Therefore, some methods dedicated to the detection and structural characterization of such by-products have emerged. However, most of these studies are usually carried out under simplified conditions (e.g. high concentration levels of micropollutants, drastic treatment conditions, use of deionized or ultrapure water) and somewhat unrealistic conditions compared to that implemented in water treatment plants. In the present study, a real field water sample was fortified at the part-per-billion level (50 μg L(-1)) with estrone-3-sulfate (E1-3S) before being ozonated (at 1 mg L(-1)) for 10 min. In a first step, targeted measurements evidenced a degradation of the parent compound (>80%) in 10 min. Secondly, a non-targeted chemical profiling approach derived from metabolomic profiling studies allowed to reveal 11 ozonation by-products, among which 4 were found predominant. The estrogenic activity of these water samples spiked with E1-3S before and after treatment was assessed by the ER-CALUX assay and was found to decrease significantly after 10 min of ozonation. Therefore, this innovative methodological strategy demonstrated its suitability and relevancy for revealing unknown compounds generated from water treatment, and permitted to generate new results regarding specifically the impact of ozonation on estrone-3-sulfate. These results confirm that ozonation is effective at removing E1-3S in drinking water and indicate that the by-products generated have significantly lower estrogenic activity. PMID:23726716

  12. Ozone: What Would It Be Like to Live in a World Where the Sun Was Dangerous?

    ERIC Educational Resources Information Center

    Clearing, 1992

    1992-01-01

    Defines ozone layer and the meaning, evidence, causes, and significance of ozone depletion. Summarizes solutions to the problem of ozone depletion and government action concerning the issue. Graphically depicts ozone depletion, global ozone loss, and how ozone is destroyed. Provides a lesson plan and listing for additional educational resources.…

  13. Upper tropospheric ozone production from lightning NOx-impacted convection: Smoke ingestion case study from the DC3 campaign

    NASA Astrophysics Data System (ADS)

    Apel, E. C.; Hornbrook, R. S.; Hills, A. J.; Blake, N. J.; Barth, M. C.; Weinheimer, A.; Cantrell, C.; Rutledge, S. A.; Basarab, B.; Crawford, J.; Diskin, G.; Homeyer, C. R.; Campos, T.; Flocke, F.; Fried, A.; Blake, D. R.; Brune, W.; Pollack, I.; Peischl, J.; Ryerson, T.; Wennberg, P. O.; Crounse, J. D.; Wisthaler, A.; Mikoviny, T.; Huey, G.; Heikes, B.; O'Sullivan, D.; Riemer, D. D.

    2015-03-01

    As part of the Deep Convective Cloud and Chemistry (DC3) experiment, the National Science Foundation/National Center for Atmospheric Research (NCAR) Gulfstream-V (GV) and NASA DC-8 research aircraft probed the chemical composition of the inflow and outflow of two convective storms (north storm, NS, south storm, SS) originating in the Colorado region on 22 June 2012, a time when the High Park wildfire was active in the area. A wide range of trace species were measured on board both aircraft including biomass burning (BB) tracers hydrogen cyanide (HCN) and acetonitrile (ACN). Acrolein, a much shorter lived tracer for BB, was also quantified on the GV. The data demonstrated that the NS had ingested fresh smoke from the High Park fire and as a consequence had a higher VOC OH reactivity than the SS. The SS lofted aged fire tracers along with other boundary layer ozone precursors and was more impacted by lightning NOx (LNOx) than the NS. The NCAR master mechanism box model was initialized with measurements made in the outflow of the two storms. The NS and SS were predicted to produce 11 and 14 ppbv of O3, respectively, downwind of the storm over 2 days. Sensitivity tests revealed that the ozone production potential of the SS was highly dependent on LNOx. Normalized excess mixing ratios, ΔX/ΔCO, for HCN and ACN were determined in both the fire plume and the storm outflow and found to be 7.0 ± 0.5 and 2.3 ± 0.5 pptv ppbv-1, respectively, and 1.4 ± 0.3 pptv ppbv-1 for acrolein in the outflow only.

  14. Ozone Therapy in Dentistry

    PubMed Central

    Domb, William C

    2014-01-01

    Summary The 21st century dental practice is quite dynamic. New treatment protocols and new materials are being developed at a rapid pace. Ozone dental therapy falls into the category of new treatment protocols in dentistry, yet ozone is not new at all. Ozone therapy is already a major treatment modality in Europe, South America and a number of other countries. What is provided here will not be an exhaustive scientific treatise so much as a brief general introduction into what dentists are now doing with ozone therapies and the numerous oral/systemic links that make this subject so important for physicians so that, ultimately, they may serve their patients more effectively and productively. PMID:25363268

  15. Gas-phase reaction products and yields of terpinolene with ozone and nitric oxide using a new derivatization agent

    NASA Astrophysics Data System (ADS)

    Ham, Jason E.; Jackson, Stephen R.; Harrison, Joel C.; Wells, J. R.

    2015-12-01

    The new derivatization agent, O-tert-butylhydroxylamine hydrochloride (TBOX) was used to investigate the carbonyl reaction products from terpinolene ozonolysis. With ozone (O3) as the limiting reagent, four carbonyl compounds were detected: methylglyoxal (MG), 4-methylcyclohex-3-en-1-one, (4MCH), 6-oxo-3-(propan-2-ylidene) heptanal (6OPH), and 3,6-dioxoheptanal (36DOH). The tricarbonyl 36DOH has not been previously observed. Using cyclohexane as a hydroxyl radical (OHrad) scavenger, the yields of 6OPH and 36DOH were reduced indicating the influence secondary OHrad radicals have on terpinolene ozonolysis products. However, the MG yield increased and the 4MCH yield was unchanged when OHrad radicals were scavenged suggesting they are only made by the terpinolene + O3 reaction. The detection of 36DOH using TBOX highlights the advantages of a smaller molecular weight derivatization agent for the detection of multi-carbonyl compounds. The product yields from terpinolene ozonolysis experiments conducted in the presence of 20 ppb nitric oxide (NO) remained unchanged except for MG which decreased. However, in experiments where O3 was kept constant at 50 ppb and NO was varied (20, 50, 100 ppb) MG, 6OPH, 36DOH decreased with increasing NO while 4MCH increased with increasing NO. The use of TBOX derivatization if combined with other derivatization agents may address a recurring need to simply and accurately detect multi-functional oxygenated species in air.

  16. Use of orbitrap-MS/MS and QSAR analyses to estimate mutagenic transformation products of iopamidol generated during ozonation and chlorination.

    PubMed

    Matsushita, Taku; Hashizuka, Masahiro; Kuriyama, Taisuke; Matsui, Yoshihiko; Shirasaki, Nobutaka

    2016-04-01

    The effects of two water purification processes (ozonation, and chlorination after ozonation) on the mutagenicity of a solution containing iopamidol (X-ray contrast medium) were investigated by using the Ames assay. No mutagenicity was observed during ozonation. In contrast, mutagenicity was induced by the ozone-treated iopamidol-containing solution after subsequent chlorination, indicating that mutagenic transformation-products (TPs) were generated. Ten of 70 peaks detected on the LC/MS total ion chromatogram (TIC) of the ozone-treated iopamidol-containing solution after chlorination had a positive correlation (r(2) > 0.6) between their peak areas and the observed mutagenicity, suggesting that TPs detected as these peaks may induce mutagenicity. To narrow down the possible contributors to the observed mutagenicity, we compared the areas of the peaks on the TIC-charts with and without chlorination. Of the ten peaks, six were also detected in the ozone-treated iopamidol-containing solution without chlorination, which did not induce mutagenicity, indicating that these peaks were not related to the observed mutagenicity. Accurate m/z values and MS/MS analysis with an orbitrap MS of the remaining four peaks revealed that two of them represented the same TP in the negative and positive ion modes. The three remaining TPs were assessed in four quantitative structure-activity relationship models for predicting Ames mutagenicity. At least one model predicted that two of the three TPs were mutagenic, whereas none of the models predicted that the other TP was a mutagen, suggesting that the former TPs, estimated as N1-acetyl-5-amino-6-chloro-2-iodobenzene-1,3-dicarboxamide and 3-hydroxy-2-{3-[(2-hydroxyethoxy)carbonyl]-2,4,6-triiodo-5-nitrobenzoyl}amino)propanoic acid, could be the candidate compounds that contributed to the observed mutagenicity. PMID:26807944

  17. Removal of the 2-mercaptobenotiazole from model wastewater by ozonation.

    PubMed

    Derco, Jan; Kassai, Angelika; Melicher, Michal; Dudas, Jozef

    2014-01-01

    The feasibility of ozonation process for 2-mercaptobenzothiazole (2-MBT) removal follows from results of ozonation of the model wastewater. Total removal of 2-MBT was observed after 20 minutes of ozonation. Very good reproducibility of repeated ozonation trials including sampling and analysis was observed. However, the majority of dissolved organic carbon (DOC) and chemical oxygen demand (COD) remained in the reaction mixture. Benzothiazole (BT) and 2-hydroxybenzothiazole (OBT) intermediates were identified during degradation of 2-MBT with ozone. In addition to the above benzothiazole derivatives, the creation of some other organic compounds follows from results of mass balance. The best fits of experimental data were obtained using the first kinetic model for 2-MBT and zero-order kinetic model for COD and DOC. The reaction time of 60 minutes can be considered as effective with regard to controlled oxidation in order to increase a portion of partially oxidized substances. Higher biodegradability and lower toxicity of ozonation products on respiration activity of activated sludge microorganisms was observed at higher ozonation time. PMID:24578619

  18. Removal of the 2-Mercaptobenotiazole from Model Wastewater by Ozonation

    PubMed Central

    Kassai, Angelika

    2014-01-01

    The feasibility of ozonation process for 2-mercaptobenzothiazole (2-MBT) removal follows from results of ozonation of the model wastewater. Total removal of 2-MBT was observed after 20 minutes of ozonation. Very good reproducibility of repeated ozonation trials including sampling and analysis was observed. However, the majority of dissolved organic carbon (DOC) and chemical oxygen demand (COD) remained in the reaction mixture. Benzothiazole (BT) and 2-hydroxybenzothiazole (OBT) intermediates were identified during degradation of 2-MBT with ozone. In addition to the above benzothiazole derivatives, the creation of some other organic compounds follows from results of mass balance. The best fits of experimental data were obtained using the first kinetic model for 2-MBT and zero-order kinetic model for COD and DOC. The reaction time of 60 minutes can be considered as effective with regard to controlled oxidation in order to increase a portion of partially oxidized substances. Higher biodegradability and lower toxicity of ozonation products on respiration activity of activated sludge microorganisms was observed at higher ozonation time. PMID:24578619

  19. Effect of urea addition on giant reed ensilage and subsequent methane production by anaerobic digestion.

    PubMed

    Liu, Shan; Ge, Xumeng; Liew, Lo Niee; Liu, Zhe; Li, Yebo

    2015-09-01

    The effect of urea addition on giant reed ensilage and sequential anaerobic digestion (AD) of the ensiled giant reed was evaluated. The dry matter loss during ensilage (up to 90 days) with or without urea addition was about 1%. Addition of 2% urea enhanced production of lactic acid by about 4 times, and reduced production of propionic acid by 2-8 times. Besides, urea addition reduced degradation of cellulose and hemicellulose, and increased degradation of lignin in giant reed during ensilage. Ensilage with or without urea addition had no significant effects on the enzymatic digestibility of giant reed, but ensilage with urea addition achieved a cumulative methane yield of 173 L/kg VS, which was 18% higher than that of fresh giant reed. The improved methane yield of giant reed could be attributed to the production of organic acids and ethanol during ensilage. PMID:26094194

  20. Sensitivity of Ozone to Bromine in the Lower Stratosphere

    NASA Technical Reports Server (NTRS)

    Salawitch, R. J.; Weisenstein, D. K.; Kovalenko, L. J.; Sioris, C. E.; Wennberg, P. O.; Chance, K.; Ko, M. K. W.; McLinden, C. A.

    2005-01-01

    Measurements of BrO suggest that inorganic bromine (Br(sub y)) at and above the tropopause is 4 to 8 ppt greater than assumed in models used in past ozone trend assessment studies. This additional bromine is likely carried to the stratosphere by short-lived biogenic compounds and their decomposition products, including tropospheric BrO. Including this additional bromine in an ozone trend simulation increases the computed ozone depletion over the past approx.25 years, leading to better agreement between measured and modeled ozone trends. This additional Br(sub y) (assumed constant over time) causes more ozone depletion because associated BrO provides a reaction partner for ClO, which increases due to anthropogenic sources. Enhanced Br(sub y) causes photochemical loss of ozone below approx.14 km to change from being controlled by HO(sub x) catalytic cycles (primarily HO2+O3) to a situation where loss by the BrO+HO2 cycle is also important.

  1. A New NASA Data Product: Tropospheric and Stratospheric Column Ozone in the Tropics Derived from TOMS Measurements

    NASA Technical Reports Server (NTRS)

    Ziemke, J. R.; Chandra, S.; Bhartia, P. K.

    1999-01-01

    Tropospheric column ozone (TCO) and stratospheric column ozone (SCO) gridded data in the tropics for 1979-present are now available from NASA Goddard Space Flight Center via either direct ftp, world-NN,ide-NN,eb, or electronic mail. This note provides a brief overview of the method used to derive the data set including validation and adjustments.

  2. Ground-level ozone in Alberta

    SciTech Connect

    Sandhu, H.S.

    1999-11-01

    This literature review on ground-level ozone in Alberta begins with introductory sections on the precursors and products of ozone formation, the chemistry and meteorology of ozone, and atmospheric ozone models. The subsequent section reviews ozone data from ambient air quality monitoring stations in Alberta. The final section discusses trends in ozone concentrations in urban and rural areas of Alberta, human and environmental health effects of ozone, proposed national ambient objectives and Canada-wide standards for ground-level ozone, and options for an ozone concentration standard for Alberta. Appendices include an outline of air pollutant monitoring methods used in Alberta, lists of monitoring stations, and tables of monitoring results for nitrogen oxides, total hydrocarbons, and volatile organic compounds at Calgary and Edmonton sites.

  3. Ground-level ozone in Alberta

    SciTech Connect

    Sandhu, H.S.

    1999-01-01

    This literature review on ground-level ozone in Alberta begins with introductory sections on the precursors and products of ozone formation, the chemistry and meteorology of ozone, and atmospheric ozone models. The subsequent section reviews ozone data from ambient air quality monitoring stations in Alberta. The final section discusses trends in ozone concentrations in urban and rural areas of Alberta, human and environmental health effects of ozone, proposed national ambient objectives and Canada-wide standards for ground-level ozone, and options for an ozone concentration standard for Alberta. Appendices include an outline of air pollutant monitoring methods used in Alberta, lists of monitoring stations, and tables of monitoring results for nitrogen oxides, total hydrocarbons, and volatile organic compounds at Calgary and Edmonton sites.

  4. Model ozone photochemistry on the basis of Solar Mesosphere Explorer mesospheric observations

    NASA Technical Reports Server (NTRS)

    Clancy, R. T.; Rusch, D. W.; Thomas, R. J.; Allen, M.; Eckman, R. S.

    1987-01-01

    Morning and afternoon mesospheric ozone profiles (50-90 km) measured by the Solar Mesosphere Explorer (SME) satellite are analyzed with one-dimensional photochemical models. The observed ozone abundances are 40 percent and 100 percent greater than the model ozone abundances at 50 and 80 km, respectively. Diurnal model calculations are compared with SME observations of ozone profiles at about 0400 and 1400 LT for high northern summer latitudes. Analysis of the ratios of these early morning and midafternoon ozone profiles provides the additional constraint that larger odd-oxygen production rates are required if lower odd-hydrogen activity is invoked to increase model O3 abundances. The increase in odd-oxygen production must be solar zenith angle independent in the mesosphere, ruling out significant changes in the Schumann-Runge band O2 opacities from Allen and Frederrick (1982).

  5. Determination of seven certified color additives in food products using liquid chromatography.

    PubMed

    Harp, Bhakti Petigara; Miranda-Bermudez, Enio; Barrows, Julie N

    2013-04-17

    This study describes a new method for determining FD&C Blue No. 1, FD&C Blue No. 2, FD&C Green No. 3, FD&C Red No. 3, FD&C Red No. 40, FD&C Yellow No. 5, and FD&C Yellow No. 6 in food products. These seven color additives are water-soluble dyes that are required to be batch certified by the U.S. Food and Drug Administration (FDA) before they may be used in food and other FDA-regulated products. In the new method, the color additives are extracted from a product using one of two procedures developed for various product types, isolated from the noncolored components, and analyzed by liquid chromatography with photodiode array detection. The method was validated by determining linearity, range, precision, recovery from various matrices, limit of detection, limit of quantitation, and relative standard deviation for each color additive. A survey of 44 food products, including beverages, frozen treats, powder mixes, gelatin products, candies, icings, jellies, spices, dressings, sauces, baked goods, and dairy products, found total color additives ranging from 1.9 to 1221 mg/kg. FDA intends to use the new method for conducting a rigorous, comprehensive dietary exposure assessment of certified color additives in products likely to be consumed by children. PMID:23528012

  6. Atmospheric production of nitrous oxide from excited ozone and its potentially important implications for global change studies

    NASA Astrophysics Data System (ADS)

    Prasad, Sheo S.; Zipf, Edward C.

    2008-08-01

    Nitrous oxide (N2O) is a greenhouse gas included in the Kyoto Protocol. Its production from excited ozone (O3) may potentially influence inverse modeling, future growth projection, and the use of mass-independent Δ17O anomaly of N2O for probing paleoatmospheric O3. On the basis of the three-component model of N2O quantum yield in photolysis of O3 in air, the globally averaged atmospheric production of N2O from O3 electronically excited by the Hartley-Huggins band and from highly vibrationally excited ground-state O3 are 1.01 and 0.26 Tg N a-1, respectively. The sum of the two productions is 9.4 and 7.7%, respectively, of the N2O from microbial and anthropogenic activities estimated by Global Emissions Inventory Activity and by the Intergovernmental Panel on Climate Change (2001). Uncertainties in these results are discussed. Subject to those uncertainties, inverse modeling of N2O that neglects productions from O3 could yield artificially magnified (by about 7%) globally averaged emission of N2O from microbial and anthropogenic activity and introduce distortion in the regional and seasonal pattern in that emission. Experiments that could narrow the uncertainties are discussed. Production from highly vibrationally excited O3 reduces the steepness in the decrease of N2O volume-mixing ratios (VMR) above 35 km. Modeled and observed VMR comparisons show latitude- and season-dependent overestimation and underestimation of the N2O VMR by models. Globally averaged comparison suggests possible N2O source deficit in the stratosphere. Limitations, uncertainties, and need for experiments associated with this possibility are also discussed. If proven real, the possible missing N2O source could influence the atmospheric affects of solar UV variability, subject to conditions that are discussed.

  7. Atmospheric photochemical transformations enhance 1,3-butadiene-induced inflammatory responses in human epithelial cells: The role of ozone and other photochemical degradation products.

    PubMed

    Doyle, Melanie; Sexton, Kenneth G; Jeffries, Harvey; Jaspers, Ilona

    2007-03-20

    Chemistry of hazardous air pollutants has been studied for many years, yet little is known about how these chemicals, once reacted within urban atmospheres, affect healthy and susceptible individuals. Once released into the atmosphere, 1,3-butadiene (BD) reacts with hydroxyl radicals and ozone (created by photochemical processes), to produce many identified and unidentified products. Once this transformation has occurred, the toxic potential of atmospheric pollutants such as BD in the ambient environment is currently unclear. During this study, environmental irradiation chambers (also called smog chambers), utilizing natural sunlight, were used to create photochemical transformations of BD. The smog chamber/in vitro exposure system was designed to investigate the toxicity of chemicals before and after photochemical reactions and to investigate interactions with the urban atmosphere using representative in vitro samples. In this study, we determined the relative toxicity and inflammatory gene expression induced by coupling smog chamber atmospheres with an in vitro system to expose human respiratory epithelial cells to BD, BDs photochemical degradation products, or the equivalent ozone generated within the photochemical mixture. Exposure to the photochemically generated products of BD (primarily acrolein, acetaldehyde, formaldehyde, furan and ozone) induced significant increases in cytotoxicity, IL-8, and IL-6 gene expression compared to a synthetic mixture of primary products that was created by injecting the correct concentrations of the detected products from the irradiation experiments. Interestingly, exposure to the equivalent levels of ozone generated during the photochemical transformation of BD did not induce the same level of inflammatory cytokine release for either exposure protocol, suggesting that the effects from ozone alone do not account for the entire response in the irradiation experiments. These results indicate that BDs full photochemical product

  8. Health Effects of a Mixture of Indoor Air Volatile Organics, Their Ozone Oxidation Products, and Stress

    PubMed Central

    Fiedler, Nancy; Laumbach, Robert; Kelly-McNeil, Kathie; Lioy, Paul; Fan, Zhi-Hua; Zhang, Junfeng; Ottenweller, John; Ohman-Strickland, Pamela; Kipen, Howard

    2005-01-01

    In our present study we tested the health effects among women of controlled exposures to volatile organic compounds (VOCs), with and without ozone (O3), and psychological stress. Each subject was exposed to the following three conditions at 1-week intervals (within-subject factor): VOCs (26 mg/m3), VOCs + O3 (26 mg/m3 + 40 ppb), and ambient air with a 1-min spike of VOCs (2.5 mg/m3). As a between-subjects factor, half the subjects were randomly assigned to perform a stressor. Subjects were 130 healthy women (mean age, 27.2 years; mean education, 15.2 years). Health effects measured before, during, and after each 140-min exposure included symptoms, neurobehavioral performance, salivary cortisol, and lung function. Mixing VOCs with O3 was shown to produce irritating compounds including aldehydes, hydrogen peroxide, organic acids, secondary organic aerosols, and ultrafine particles (particulate matter with aerodynamic diameter < 0.1 μm). Exposure to VOCs with and without O3 did not result in significant subjective or objective health effects. Psychological stress significantly increased salivary cortisol and symptoms of anxiety regardless of exposure condition. Neither lung function nor neurobehavioral performance was compromised by exposure to VOCs or VOCs + O3. Although numerous epidemiologic studies suggest that symptoms are significantly increased among workers in buildings with poor ventilation and mixtures of VOCs, our acute exposure study was not consistent with these epidemiologic findings. Stress appears to be a more significant factor than chemical exposures in affecting some of the health end points measured in our present study. PMID:16263509

  9. The use of NaCl addition for the improvement of polyhydroxyalkanoate production by Cupriavidus necator.

    PubMed

    Passanha, Pearl; Kedia, Gopal; Dinsdale, Richard M; Guwy, Alan J; Esteves, Sandra R

    2014-07-01

    External stress factors in the form of ionic species or temperature increases have been shown to produce a stress response leading to enhanced PHA production. The effect of five different NaCl concentrations, namely 3.5, 6.5, 9, 12 and 15 g/l NaCl on PHA productivity using Cupriavidus necator has been investigated alongside a control (no added NaCl). A dielectric spectroscopy probe was used to measure PHA accumulation online in conjunction with the chemical offline analysis of PHA. The highest PHA production was obtained with the addition of 9 g/l NaCl, which yielded 30% higher PHA than the control. Increasing the addition of NaCl to 15 g/l was found to inhibit the production of PHA. NaCl addition can therefore be used as a simple, low cost, sustainable, non toxic and non reactive external stress strategy for increasing PHA productivity. PMID:24835740

  10. Ozone studies in the Paso del Norte region

    NASA Astrophysics Data System (ADS)

    Becerra-Davila, Fernando

    obtained from this photolysis study demonstrate that the local ground level ozone formation is not only influenced by the strong solar radiation and changing aerosol makeup, but also by other heterogeneous factors and reactions. In addition, this research provided good evidence that the ground level ozone precursor regime in El Paso during the ozone episode of June 2006 was mostly VOC-limited. Much of this estimation was derived from measurements of local ambient VOC/NOx ratios. This finding shows that at least during June 2006, the non-linear surface ozone production increased during weekends compared to workdays in a habitually VOC-limited regime. The seasonal variations of columnar ozone as measured by a Multi-filter Rotating Shadowband instrument installed at the UTEP campus are analyzed for the first time for this region and results are presented. This investigation has addressed the problem of ground-level ozone formation in the Paso del Norte region. Urban ozone is a complex problem with many aspects that are not fully understood. In this investigation, a range of techniques has been used to address the study of local surface ozone episodes with the purpose of acquiring new insights and knowledge that will help understand and remediate the diverse atmospheric pollution events that affect this bi-national region recurrently. Innovative techniques were developed and used, ranging from the use of local ambient atmospheric pollution data to the utilization of complex modeling techniques to achieve the best possible computer results. Finally, the influence of ground level ozone concentrations in admissions to hospitals for this region due to respiratory diseases is analyzed. The comprehensive results obtained in this work will help to better understand ozone formation in the Paso del Norte Region for future policy regulation implementations.

  11. Mutagenic activity of the products of ozone reaction with propylene in the presence and absence of nitrogen dioxide

    SciTech Connect

    Shepson, P.B.; Kleindienst, T.E.; Edney, E.O.; Cupitt, L.T.; Claxton, L.D.

    1985-01-01

    In a 22.7 cu.m. flow mode smog chamber, 5.4 ppm proylene was allowed to react with 0.9 ppm ozone either in the presence or absence of 0.2 ppm nitrogen dioxide. The steady-state reactant and product distribution was then tested for total mutagenic activity by exposing Salmonella typhimurium strain TA100 to the gasphase chamber effluent. The total product dosage in the test plates was varied by exposing them for 0, 5, 10, 15, and 20 h. Salmonella typhimurium survivor levels were obtained at each length of exposure. The number of revertants/plate increased at a rate of approx. 4-5 per hour, while the survivor level decreased throughout the exposure. Most of the total mutagenic activity can be accounted for by the presence of formaldehyde. This work clearly demonstrates that a gas-phase exposure of Salmonella typhimurium can be effectively employed as an alternative to the standard plate incorporation test for volatile species and for complex gas phase mixtures.

  12. An Inventory of Methods for the Assessment of Additive Increased Addictiveness of Tobacco Products

    PubMed Central

    van de Nobelen, Suzanne; Kienhuis, Anne S.

    2016-01-01

    Background: Cigarettes and other forms of tobacco contain the addictive drug nicotine. Other components, either naturally occurring in tobacco or additives that are intentionally added during the manufacturing process, may add to the addictiveness of tobacco products. As such, these components can make cigarette smokers more easily and heavily dependent. Efforts to regulate tobacco product dependence are emerging globally. Additives that increase tobacco dependence will be prohibited under the new European Tobacco Product Directive. Objective: This article provides guidelines and recommendations for developing a regulatory strategy for assessment of increase in tobacco dependence due to additives. Relevant scientific literature is summarized and criteria and experimental studies that can define increased dependence of tobacco products are described. Conclusions: Natural tobacco smoke is a very complex matrix of components, therefore analysis of the contribution of an additive or a combination of additives to the level of dependence on this product is challenging. We propose to combine different type of studies analyzing overall tobacco product dependence potential and the functioning of additives in relation to nicotine. By using a combination of techniques, changes associated with nicotine dependence such as behavioral, physiological, and neurochemical alterations can be examined to provide sufficient information. Research needs and knowledge gaps will be discussed and recommendations will be made to translate current knowledge into legislation. As such, this article aids in implementation of the Tobacco Product Directive, as well as help enable regulators and researchers worldwide to develop standards to reduce dependence on tobacco products. Implications: This article provides an overall view on how to assess tobacco product constituents for their potential contribution to use and dependence. It provides guidelines that help enable regulators worldwide to

  13. A test strategy for the assessment of additive attributed toxicity of tobacco products.

    PubMed

    Kienhuis, Anne S; Staal, Yvonne C M; Soeteman-Hernández, Lya G; van de Nobelen, Suzanne; Talhout, Reinskje

    2016-08-01

    The new EU Tobacco Product Directive (TPD) prohibits tobacco products containing additives that are toxic in unburnt form or that increase overall toxicity of the product. This paper proposes a strategy to assess additive attributed toxicity in the context of the TPD. Literature was searched on toxicity testing strategies for regulatory purposes from tobacco industry and governmental institutes. Although mainly traditional in vivo testing strategies have been applied to assess toxicity of unburnt additives and increases in overall toxicity of tobacco products due to additives, in vitro tests combined with toxicogenomics and validated using biomarkers of exposure and disease are most promising in this respect. As such, tests are needed that are sensitive enough to assess additive attributed toxicity above the overall toxicity of tobacco products, which can associate assay outcomes to human risk and exposure. In conclusion, new, sensitive in vitro assays are needed to conclude whether comparable testing allows for assessment of small changes in overall toxicity attributed to additives. A more pragmatic approach for implementation on a short-term is mandated lowering of toxic emission components. Combined with risk assessment, this approach allows assessment of effectiveness of harm reduction strategies, including banning or reducing of additives. PMID:27155068

  14. 39 CFR 3055.6 - Addition of new market dominant products or changes to existing market dominant products.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 39 Postal Service 1 2014-07-01 2014-07-01 false Addition of new market dominant products or changes to existing market dominant products. 3055.6 Section 3055.6 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Annual Reporting of...

  15. 39 CFR 3055.6 - Addition of new market dominant products or changes to existing market dominant products.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 39 Postal Service 1 2013-07-01 2013-07-01 false Addition of new market dominant products or changes to existing market dominant products. 3055.6 Section 3055.6 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Annual Reporting of...

  16. 39 CFR 3055.6 - Addition of new market dominant products or changes to existing market dominant products.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Addition of new market dominant products or changes to existing market dominant products. 3055.6 Section 3055.6 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL SERVICE PERFORMANCE AND CUSTOMER SATISFACTION REPORTING Annual Reporting of...

  17. 78 FR 77384 - DSM Nutritional Products; Filing of Food Additive Petition (Animal Use)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-23

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Part 573 DSM Nutritional Products; Filing of Food Additive Petition (Animal Use) AGENCY: Food and Drug Administration, HHS. ACTION: Notice of petition. SUMMARY: The Food and Drug Administration (FDA) is announcing that DSM Nutritional Products has filed...

  18. Protease addition to increase yield and fermentation rate in dry grind ethanol production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using a small scale laboratory procedure (100g shake flasks) for ethanol production from corn, the effects of acid protease addition during the fermentation step were evaluated. The batch fermentations were conducted in duplicate using standard conditions and with protease addition during fermentati...

  19. Nonaqueous ozonation of vulcanized rubber

    DOEpatents

    Serkiz, Steven M.

    1999-01-01

    A process and resulting product is provided in which a solid particulate, such as vulcanized crumb rubber, has the surface functional groups oxidized by ozonation using a nonpolar solvent. The ozonation process renders the treated crumb rubber more suitable for use in new rubber formulations. As a result, larger loading levels of the treated crumb rubber can be used in new rubber mixtures.

  20. Nonaqueous ozonation of vulcanized rubber

    SciTech Connect

    Serkiz, S.M.

    1999-12-07

    A process and resulting product are provided in which a solid particulate, such as vulcanized crumb rubber, has the surface functional groups oxidized by ozonation using a nonpolar solvent. The ozonation process renders the treated crumb rubber more suitable for use in new rubber formulations. As a result, larger loading levels of the treated crumb rubber can be used in new rubber mixtures.

  1. Rocket ozone sounding network data

    NASA Technical Reports Server (NTRS)

    Wright, D. U.; Krueger, A. J.; Foster, G. M.

    1979-01-01

    During the period March 1977 through May 1977, three regular monthly ozone profiles were measured at Wallops Flight Center and three regular monthly ozone profiles were measured at the Churchill Research Range. One additional flight was conducted at Wallops Flight Center in support of Nimbus 4 SBUV. Data results and flight profiles for the period covered are presented.

  2. Drivers of changes in stratospheric and tropospheric ozone between year 2000 and 2100

    NASA Astrophysics Data System (ADS)

    Banerjee, A.; Maycock, A. C.; Archibald, A. T.; Abraham, N. L.; Telford, P.; Braesicke, P.; Pyle, J. A.

    2015-11-01

    A stratosphere-resolving configuration of the Met Office's Unified Model (UM) with the United Kingdom Chemistry and Aerosols (UKCA) scheme is used to investigate the atmospheric response to changes in (a) greenhouse gases and climate, (b) ozone-depleting substances (ODSs) and (c) non-methane ozone precursor emissions. A suite of time-slice experiments show the separate, as well as pairwise, impacts of these perturbations between the years 2000 and 2100. Sensitivity to uncertainties in future greenhouse gases and aerosols is explored through the use of the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios. The results highlight an important role for the stratosphere in determining the annual mean tropospheric ozone response, primarily through stratosphere-troposphere exchange of ozone (STE). Under both climate change and reductions in ODSs, increases in STE offset decreases in net chemical production, leading to overall increases in the tropospheric ozone burden. This opposes the effects of projected decreases in ozone precursors through measures to improve air quality, which act to reduce the ozone burden. The global tropospheric lifetime of ozone (τO3) does not change significantly under climate change at RCP4.5, but it decreases at RCP8.5. This opposes the increases in τO3 simulated under reductions in both ODSs and ozone precursor emissions. The additivity of the changes in ozone is examined by comparing the sum of the responses in the single-forcing experiments to those from equivalent combined-forcing experiments. Whilst the ozone responses to most forcing combinations are found to be approximately additive, non-additive changes are found in both the stratosphere and troposphere when a large climate forcing (RCP8.5) is combined with the effects of ODSs.

  3. Drivers of changes in stratospheric and tropospheric ozone between year 2000 and 2100

    NASA Astrophysics Data System (ADS)

    Banerjee, Antara; Maycock, Amanda C.; Archibald, Alexander T.; Abraham, N. Luke; Telford, Paul; Braesicke, Peter; Pyle, John A.

    2016-03-01

    A stratosphere-resolving configuration of the Met Office's Unified Model (UM) with the United Kingdom Chemistry and Aerosols (UKCA) scheme is used to investigate the atmospheric response to changes in (a) greenhouse gases and climate, (b) ozone-depleting substances (ODSs) and (c) non-methane ozone precursor emissions. A suite of time-slice experiments show the separate, as well as pairwise, impacts of these perturbations between the years 2000 and 2100. Sensitivity to uncertainties in future greenhouse gases and aerosols is explored through the use of the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios. The results highlight an important role for the stratosphere in determining the annual mean tropospheric ozone response, primarily through stratosphere-troposphere exchange (STE) of ozone. Under both climate change and reductions in ODSs, increases in STE offset decreases in net chemical production and act to increase the tropospheric ozone burden. This opposes the effects of projected decreases in ozone precursors through measures to improve air quality, which act to reduce the ozone burden. The global tropospheric lifetime of ozone (τO3) does not change significantly under climate change at RCP4.5, but it decreases at RCP8.5. This opposes the increases in τO3 simulated under reductions in ODSs and ozone precursor emissions. The additivity of the changes in ozone is examined by comparing the sum of the responses in the single-forcing experiments to those from equivalent combined-forcing experiments. Whilst the ozone responses to most forcing combinations are found to be approximately additive, non-additive changes are found in both the stratosphere and troposphere when a large climate forcing (RCP8.5) is combined with the effects of ODSs.

  4. A Case Study On the Relative Influence of Free Tropospheric Subsidence, Long Range Transport and Local Production in Modulating Ozone Concentrations over Qatar

    NASA Astrophysics Data System (ADS)

    Ayoub, Mohammed; Ackermann, Luis; Fountoukis, Christos; Gladich, Ivan

    2016-04-01

    The Qatar Environment and Energy Research Institute (QEERI) operates a network of air quality monitoring stations (AQMS) around the Doha metropolitan area and an ozonesonde station with regular weekly launches and occasional higher frequency launch experiments (HFLE). Six ozonesondes were launched at 0700 LT/0400 UTC and 1300 LT/1000 UTC over a three day period between 10-12 September, 2013. We present the analysis of the ozonesonde data coupled with regional chemical transport modeling over the same time period using WRF-Chem validated against both the ozonesonde and surface AQMS measurements. The HFLE and modeling show evidence of both subsidence and transboundary transport of ozone during the study period, coupled with a strong sea breeze circulation on the 11th of September resulting in elevated ozone concentrations throughout the boundary layer. The development of the sea breeze during the course of the day and influence of the early morning residual layer versus daytime production is quantified. The almost complete titration of ozone in the morning hours of 11 September, 2013 is attributed to local vehicular emissions of NOx and stable atmospheric conditions prevailing over the Doha area. The relative contribution of long range transport of ozone along the Arabian Gulf coast and local urban emissions are discussed.

  5. Ozonation effect on natural organic matter adsorption and biodegradation--application to a membrane bioreactor containing activated carbon for drinking water production.

    PubMed

    Treguer, Ronan; Tatin, Romuald; Couvert, Annabelle; Wolbert, Dominique; Tazi-Pain, Annie

    2010-02-01

    More stringent legislation on dissolved organic matter (DOM) urges the drinking water industry to improve in DOM removal, especially when applied to water with high dissolved organic carbon (DOC) contents and low turbidity. To improve conventional processes currently used in drinking water treatment plants (DWTPs), the performances of a hybrid membrane bioreactor containing fluidized activated carbon were investigated at the DWTP of Rennes. Preliminary results showed that the residual DOC was the major part of the non-biodegradable fraction. In order to increase the global efficiency, an upstream oxidation step was added to the process. Ozone was chosen to break large molecules and increase their biodegradability. The first step consisted of carrying out lab-scale experiments in order to optimise the necessary ozone dose by measuring the process yield, in terms of biodegradable dissolved organic carbon (BDOC). Secondly, activated carbon adsorption of the DOC present in ozonated water was quantified. The whole process was tested in a pilot unit under field conditions at the DWTP of Rennes (France). Lab-scale experiments confirmed that ozonation increases the BDOC fraction, reduces the aromaticity of the DOC and produces small size organic compounds. Adsorption tests led to the conclusion that activated carbon unexpectedly removes BDOC first. Finally, the pilot unit results revealed an additional BDOC removal (from 0.10 to 0.15 mg L(-1)) of dissolved organic carbon from the raw water considered. PMID:19906398

  6. IDENTIFICATION OF BROMOHYDRINS IN OZONATED WATERS

    EPA Science Inventory

    Because ozonation is becoming a popular alternative to chlorination for disinfection of drinking water and because little is known about the potential adverse effects of ozonation disinfection by-products (DBPs), we have sought to identify ozone DBPs, particularly brominated orga...

  7. Photoinduced degradation of PAHs in the presence of ozone

    SciTech Connect

    Schutt, W.S.; Li, Y.; Sigman, M.E. |

    1995-12-31

    Polycyclic Aromatic Hydrocarbons (PAH) are formed from both anthropogenic and natural sources. In order to assess the environmental impact caused by the surface-adsorbed PAHs, the chemical lifetimes of these compounds in the atmosphere must be determined. Although ozone is known to be a primary reactant in the chemical transformation of surface-adsorbed PAHs in the atmosphere, the kinetics of these reactions have not been investigated in detail. In addition to the experimental difficulties that arise in using an oxygen-ozone stream while monitoring the PAH with fluorescence, complications in analyzing the kinetic mechanism also exist. It is difficult to determine whether the ozone or oxygen initially quenches the excited state of PAH. Ozone could enhance the degradation rate by simply reacting with a product derived from the excited state of PAH and oxygen. The focus of this study is to demonstrate the use of fluorescence spectroscopy in monitoring the degradation of PAH adsorbed on a three dimensional particle in the presence of gaseous ozone free from the interference of oxygen. More specifically, the experimental procedure will involve the generation of an ozone-nitrogen gas stream to be used in the investigation of dark and photochemical reactions between ozone and naphthalene. The absence of oxygen in the system will allow for the accurate monitoring of PAH fluorescence decay due solely to ozone quenching. It will also aid in the determination of the reaction mechanism. This is the first time that the direct interaction of ozone with an excited state of PAH has been demonstrated.

  8. Shift in metabolism towards ethanol production in Saccharomyces cerevisiae by addition of metabolic inhibitors

    SciTech Connect

    Hahn-Haegerdal, B.; Mattiasson, B.

    1982-01-01

    The future exploitation of fermentation processes for the production of bulk chemicals will very much depend on whether product yield and product concentration can be improved. At the present time the cost for the raw material and the product upgrading limits the competitiveness of fermentation processes in relation to petrochemical processes. Much effort is put into selecting microbial strains with higher product yields as well as improved tolerance towards increased product concentrations. This approach is rather laborious and time-consuming and the overall goal will be beneficial if it is complemented with other techniques. This investigation will describe how productivity migh be improved by addition of a specific metabolic inhibitor, sodium azide, which inhibits the cytochrome oxidase of the respiratory chain. As a model for these studies Saccaromyces cerevisiae fermenting glucose to ethanol was chosen.

  9. Source attribution of tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Butler, T. M.

    2015-12-01

    Tropospheric ozone is a harmful pollutant with adverse effects on human health and ecosystems. As well as these effects, tropospheric ozone is also a powerful greenhouse gas, with an anthropogenic radiative forcing one quarter of that of CO2. Along with methane and atmospheric aerosol, tropospheric ozone belongs to the so-called Short Lived Climate forcing Pollutants, or SLCP. Recent work has shown that efforts to reduce concentrations of SLCP in the atmosphere have the potential to slow the rate of near-term climate change, while simultaneously improving public health and reducing crop losses. Unlike many other SLCP, tropospehric ozone is not directly emitted, but is instead influenced by two distinct sources: transport of air from the ozone-rich stratosphere; and photochemical production in the troposphere from the emitted precursors NOx (oxides of nitrogen), CO (Carbon Monoxide), and VOC (volatile organic compounds, including methane). Better understanding of the relationship between ozone production and the emissions of its precursors is essential for the development of targeted emission reduction strategies. Several modeling methods have been employed to relate the production of tropospheric ozone to emissions of its precursors; emissions perturbation, tagging, and adjoint sensitivity methods all deliver complementary information about modelled ozone production. Most studies using tagging methods have focused on attribution of tropospheric ozone production to emissions of NOx, even though perturbation methods have suggested that tropospheric ozone is also sensitive to VOC, particularly methane. In this study we describe the implementation into a global chemistry-climate model of a scheme for tagging emissions of NOx and VOC with an arbitrary number of labels, which are followed through the chemical reactions of tropospheric ozone production in order to perform attribution of tropospehric ozone to its emitted precursors. Attribution is performed to both

  10. Response of lightning NOx emissions and ozone production to climate change: Insights from the Atmospheric Chemistry and Climate Model Intercomparison Project

    NASA Astrophysics Data System (ADS)

    Finney, D. L.; Doherty, R. M.; Wild, O.; Young, P. J.; Butler, A.

    2016-05-01

    Results from an ensemble of models are used to investigate the response of lightning nitrogen oxide emissions to climate change and the consequent impacts on ozone production. Most models generate lightning using a parameterization based on cloud top height. With this approach and a present-day global emission of 5 TgN, we estimate a linear response with respect to changes in global surface temperature of +0.44 ± 0.05 TgN K-1. However, two models using alternative approaches give +0.14 and -0.55 TgN K-1 suggesting that the simulated response is highly dependent on lightning parameterization. Lightning NOx is found to have an ozone production efficiency of 6.5 ± 4.7 times that of surface NOx sources. This wide range of efficiencies across models is partly due to the assumed vertical distribution of the lightning source and partly to the treatment of nonmethane volatile organic compound (NMVOC) chemistry. Careful consideration of the vertical distribution of emissions is needed, given its large influence on ozone production.

  11. Evaluation of sorghum flour functionality and quality characteristics of gluten-free bread and cake as influenced by ozone treatment.

    PubMed

    Marston, Kathryn; Khouryieh, Hanna; Aramouni, Fadi

    2015-12-01

    Commercially milled food-grade sorghum flour was subjected to ozone at the rate of 0.06 L/min for 15, 30, and 45 min. The pH of ozone-treated flour decreased as exposure time increased. The L* (lightness) values of sorghum flour significantly increased (p < 0.05), while the b* (yellowness) values significantly decreased as ozone exposure time increased. Peak viscosity significantly increased as time of ozonation increased from 0 to 45 min. Results showed that gluten-free cake volume significantly increased as ozonation time increased. Additionally, longer ozonation exposure times increased cells per slice area, lightness, and slice brightness values in gluten-free cakes while reducing crumb firmness. Despite improving lightness and slice brightness values, ozonation did not significantly increase the specific volume of gluten-free batter-based bread. While ozonation improved the volume and texture in cakes, it did not have the same positive effects on gluten-free bread. Bread made from ozonated sorghum flour had an open ragged structure with equivalent volume to the control flour. In both applications, the increased brightness and lightness values due to ozone exposure is recommended to increase the acceptability of sorghum products. PMID:25406134

  12. The Effect of Ethene and Propene Emissions on Ozone Production in Houston during the TexAQS 2000 Field Campaign.

    NASA Astrophysics Data System (ADS)

    Fast, J. D.; Jiang, G.

    2002-12-01

    A coupled meteorological and chemical model, PEGASUS, was used to simulate ozone and ozone precursors in the vicinity of Houston between 28 August and 1 September during the 2000 TexAQS Field Campaign. A nested grid configuration was used with an outer grid encompassing the south-central U.S. with a grid spacing of 16 km and an inner grid encompassing the Houston metropolitan area with a 1.3 km grid spacing. Area, mobile, biogenic, and point source emission rates were based on a data set provided by the Texas Natural Resource Conservation Commission (TRNCC). The meteorological model employed data assimilation using observations from five radar wind profilers to limit forecast errors in the simulated wind fields around Houston. The simulated magnitude and distribution of ozone over downtown Houston was very similar to observations from the surface monitoring network. Observed and simulated ozone mixing ratios were as high as 140 ppb on 31 August. The model results were also in very good agreement with the spatial distribution of ozone, NOx, and NOy observed aloft by research aircraft. However, at surface stations and aircraft positions close to large point source emissions of VOCs, the simulated ozone mixing ratios were usually too low. For example, ozone mixing ratios at LaPorte were about 200 ppb on 30 and 31 August, but the predicted values at that location were between 110 and 120 ppb. Simulated VOCs, including propene and ethene, were also under-predicted. To examine whether an underestimation of the VOC point source emission rates may have contributed to the low ozone mixing ratios predicted by the model, two sensitivity simulations were performed in which the point source emission rates of ethene and propene were increased by a factor of 5 and 10. With the increased point source emission rates, ozone and VOC predictions were in better agreement with the surface and aircraft observations. Trajectories from the model indicated that the high ozone and VOC

  13. Polar ozone

    NASA Technical Reports Server (NTRS)

    Solomon, S.; Grose, W. L.; Jones, R. L.; Mccormick, M. P.; Molina, Mario J.; Oneill, A.; Poole, L. R.; Shine, K. P.; Plumb, R. A.; Pope, V.

    1990-01-01

    The observation and interpretation of a large, unexpected ozone depletion over Antarctica has changed the international scientific view of stratospheric chemistry. The observations which show the veracity, seasonal nature, and vertical structure of the Antarctic ozone hole are presented. Evidence for Arctic and midlatitude ozone loss is also discussed. The chemical theory for Antarctic ozone depletion centers around the occurrence of polar stratospheric clouds (PSCs) in Antarctic winter and spring; the climatology and radiative properties of these clouds are presented. Lab studies of the physical properties of PSCs and the chemical processes that subsequently influence ozone depletion are discussed. Observations and interpretation of the chemical composition of the Antarctic stratosphere are described. It is shown that the observed, greatly enhanced abundances of chlorine monoxide in the lower stratosphere are sufficient to explain much if not all of the ozone decrease. The dynamic meteorology of both polar regions is given, interannual and interhemispheric variations in dynamical processes are outlined, and their likely roles in ozone loss are discussed.

  14. Ozone decomposition

    PubMed Central

    Batakliev, Todor; Georgiev, Vladimir; Anachkov, Metody; Rakovsky, Slavcho

    2014-01-01

    Catalytic ozone decomposition is of great significance because ozone is a toxic substance commonly found or generated in human environments (aircraft cabins, offices with photocopiers, laser printers, sterilizers). Considerable work has been done on ozone decomposition reported in the literature. This review provides a comprehensive summary of the literature, concentrating on analysis of the physico-chemical properties, synthesis and catalytic decomposition of ozone. This is supplemented by a review on kinetics and catalyst characterization which ties together the previously reported results. Noble metals and oxides of transition metals have been found to be the most active substances for ozone decomposition. The high price of precious metals stimulated the use of metal oxide catalysts and particularly the catalysts based on manganese oxide. It has been determined that the kinetics of ozone decomposition is of first order importance. A mechanism of the reaction of catalytic ozone decomposition is discussed, based on detailed spectroscopic investigations of the catalytic surface, showing the existence of peroxide and superoxide surface intermediates. PMID:26109880

  15. Ozone decomposition.

    PubMed

    Batakliev, Todor; Georgiev, Vladimir; Anachkov, Metody; Rakovsky, Slavcho; Zaikov, Gennadi E

    2014-06-01

    Catalytic ozone decomposition is of great significance because ozone is a toxic substance commonly found or generated in human environments (aircraft cabins, offices with photocopiers, laser printers, sterilizers). Considerable work has been done on ozone decomposition reported in the literature. This review provides a comprehensive summary of the literature, concentrating on analysis of the physico-chemical properties, synthesis and catalytic decomposition of ozone. This is supplemented by a review on kinetics and catalyst characterization which ties together the previously reported results. Noble metals and oxides of transition metals have been found to be the most active substances for ozone decomposition. The high price of precious metals stimulated the use of metal oxide catalysts and particularly the catalysts based on manganese oxide. It has been determined that the kinetics of ozone decomposition is of first order importance. A mechanism of the reaction of catalytic ozone decomposition is discussed, based on detailed spectroscopic investigations of the catalytic surface, showing the existence of peroxide and superoxide surface intermediates. PMID:26109880

  16. Distribution of total ozone and stratospheric ozone in the tropics - Implications for the distribution of tropospheric ozone

    NASA Technical Reports Server (NTRS)

    Fishman, Jack; Larsen, Jack C.

    1987-01-01

    Climatologies of total columnar ozone and integrated stratospheric ozone amounts at low latitudes (15 deg N to 15 deg S), derived from satellite observations, are presented. A significant longitudinal variability in total ozone is present, with highest values generally located between 60 deg W and 60 deg E. The integrated stratospheric component of total ozone, on the other hand, does not exhibit a longitudinal preference for high values. Therefore it is hypothesized that the climatological longitudinal distribution of total ozone reflects the variability of the abundance of tropospheric ozone at low latitudes. Furthermore, it is speculated that in situ photochemical production of ozone resulting from biomass burning may be responsible for the observed enhancement of total ozone at these longitudes.

  17. Enhanced photo-fermentative H2 production using Rhodobacter sphaeroides by ethanol addition and analysis of soluble microbial products

    PubMed Central

    2014-01-01

    Background Biological fermentation routes can provide an environmentally friendly way of producing H2 since they use renewable biomass as feedstock and proceed under ambient temperature and pressure. In particular, photo-fermentation has superior properties in terms of achieving high H2 yield through complete degradation of substrates. However, long-term H2 production data with stable performance is limited, and this data is essential for practical applications. In the present work, continuous photo-fermentative H2 production from lactate was attempted using the purple non-sulfur bacterium, Rhodobacter sphaeroides KD131. As a gradual drop in H2 production was observed, we attempted to add ethanol (0.2% v/v) to the medium. Results As continuous operation went on, H2 production was not sustained and showed a negligible H2 yield (< 0.5 mol H2/mol lactateadded) within two weeks. Electron balance analysis showed that the reason for the gradual drop in H2 production was ascribed to the increase in production of soluble microbial products (SMPs). To see the possible effect of ethanol addition, a batch test was first conducted. The presence of ethanol significantly increased the H2 yield from 1.15 to 2.20 mol H2/mol lactateadded, by suppressing the production of SMPs. The analysis of SMPs by size exclusion chromatography showed that, in the later period of fermentation, more than half of the low molecular weight SMPs (< 1 kDa) were consumed and used for H2 production when ethanol had been added, while the concentration of SMPs continuously increased in the absence of ethanol. It was found that the addition of ethanol facilitated the utilization of reducing power, resulting in an increase in the cellular levels of NAD+ and NADP+. In continuous operation, ethanol addition was effective, such that stable H2 production was attained with an H2 yield of 2.5 mol H2/mol lactateadded. Less than 15% of substrate electrons were used for SMP production, whereas 35% were used in

  18. Kinetics of pulp mill effluent treatment by ozone-based processes.

    PubMed

    Ko, Chun-Han; Hsieh, Po-Hung; Chang, Meng-Wen; Chern, Jia-Ming; Chiang, Shih-Min; Tzeng, Chewn-Jeng

    2009-09-15

    The wastewaters generated from wood pulping and paper production processes are traditionally treated by biological and physicochemical processes. In order to reduce chemical oxygen demand (COD) and color to meet increasingly strict discharge standards, advanced oxidation processes (AOPs) are being adapted as polishing treatment units. Various ozone-based processes were used in this study to treat simulated wastewaters prepared from black liquor from a hardwood Kraft pulp mill in Taiwan. The experimental results showed that the COD and color were primarily removed by direct ozone oxidation and activated carbon adsorption. While the addition of activated carbon could enhance the COD and color removal during ozonation, the addition of hydrogen peroxide improved the color removal only. For the various ozone-based treatment processes, kinetic models were developed to satisfactorily predict the COD and color removal rates. According to the kinetic parameters obtained from the various ozone-based processes, the enhanced COD and color removal of ozonation in the presence of activated carbon was attributed to the regeneration of the activated carbon by ozonation. These kinetic models can be used for reactor design and process design to treat pulping wastewater using ozone-based processes. PMID:19304380

  19. How do changes in the stratospheric circulation impact ozone?

    NASA Astrophysics Data System (ADS)

    Garny, Hella; Dameris, Martin; Bodeker, Greg; Grewe, Volker; Stenke, Andrea

    2010-05-01

    The Brewer-Dobson circulation (BDC) and tropical upwelling in the lower stratosphere are predicted to increase with increasing greenhouse gas (GHG) concentrations by most climate models and chemistry-climate models (CCMs). This change in the meridional circulation is likely to alter the transport of trace gases, and in particular ozone. In addition, ozone is affected by other processes such as changes in stratospheric temperatures that act to change the reaction rates of ozone-relevant chemistry. These climate-change related modifications of the ozone amount and distribution are superimposed on the depletion and recovery of the ozone layer due to stratospheric halogen loading. To assess the recovery of ozone correctly, it is important to understand the processes that affect ozone in a changing climate. In this study, multiple transient numerical simulations and complementary sensitivity studies with the E39CA CCM are used to disentangle the direct effect of changes in GHG concentrations, the indirect effect of GHG-induced sea surface temperature (SST) changes, and changes in CFC concentrations. It is shown that the increase in tropical upwelling is driven by the changes in SSTs rather than by the direct radiative effect of increased GHG concentrations. Therefore, the sensitivity simulations that separate the direct effect of increased amounts of GHGs and the indirect effect via increased SSTs can be used to separate the impact of the increase in tropical upwelling and the impact of stratospheric cooling on ozone. It is shown that the changes in the meridional circulation cause weak negative trends in the tropical lower stratosphere and associated positive trends in the extra-tropical lower stratosphere. Stratospheric cooling, on the other hand, causes a broad increase in ozone in the stratosphere. To study the processes that lead to changes in the ozone distribution in more detail, different diagnostics that can separate the changes in chemistry (production or

  20. Effects of ozone and photochemical oxidants on interferon production by rabbit alveolar macrophages

    SciTech Connect

    Shingu, H.; Sugiyama, M.; Watanabe, M.; Nakajima, T.

    1980-03-01

    The results obtained in this study demonstrated that the capacity of interferon production by alveolar macrophage was depressed immediately after exposure to O/sub 3/ greater than 1 ppM or Ox exceeding average of 0.3 ppM (max. 0.7 ppM) for 3 hours. In these experiments, it was shown that depression in interferon production corresponded in degree to elevation of gas concentration. This finding suggested that alveolar macrophages, existing in a state of single cell in the lung, were probably exposed directly to the inhaled gas in this experimental system. The results that depression of interferon production in Dutch rabbit under the same O/sub 3/ concentration was greater in degree than that in rabbit suggest that sensitivity of alveolar macrophage to O/sub 3/ or presumably to other irritating gases is different among species.

  1. A Study on Generation Ice Containing Ozone

    NASA Astrophysics Data System (ADS)

    Yoshimura, Kenji; Koyama, Shigeru; Yamamoto, Hiromi

    Ozone has the capability of sterilization and deodorization due to high oxidation power. It is also effective for the conservation of perishable foods and purification of water. However, ozone has a disadvantage, that is, conservation of ozone is difficult because it changes back into oxygen. Recently, ice containing ozone is taken attention for the purpose of its conservation. The use of ice containing ozone seems to keep food fresher when we conserve and transport perishable foods due to effects of cooling and sterilization of ice containing ozone. In the present study, we investigated the influence of temperatures of water dissolving ozone on the timewise attenuations of ozone concentration in water. We also investigated the influence of cooling temperature, ice diameter, initial temperatures of water dissolving ozone and container internal pressure of the water dissolving ozone on ozone concentration in the ice. In addition, we investigated the influence of the ice diameter on the timewise attenuations of ozone concentration in the ice. It was confirmed that the solidification experimental data can be adjusted by a correlation between ozone concentration in the ice and solidification time.

  2. Enhancement of antibody production by growth factor addition in perfusion and hollow-fiber culture systems.

    PubMed

    Omasa, T; Kobayashi, M; Nishikawa, T; Shioya, S; Suga, K; Uemura, S; Kitani, Y; Imamura, Y

    1995-12-20

    The effects of the high-molecular-weight growth factors, transferrin and bovine serum albumin (BSA), on antibody production were analyzed quantitatively in continuous hollow-fiber cultivation over a period of 60 days. Transferrin enhanced cell growth but had no significant effect on the specific antibody production rate, whereas BSA significantly enhanced antibody production. The antibody production rate was increased 4- and 14-fold respectively by feeding BSA at 2 and 5 g L(-1) into the EC side of the system (the side connected to the cell-containing outer part of the hollow-fiber unit) compared with the production achieved without BSA. Addition of 5 g L(1) BSA into the IC side of the system (the side connected to the inner part of the hollow-fiber unit) resulted in a 2.5-fold increase in the antibody production rate. The effect of BSA was also analyzed using the perfusion culture system with a separation unit. When fresh medium containing either 2 or 5 g L(-1) BSA was fed into the reactor, both the specific growth rate and specific death rate increased, while the specific antibody production rate was increased 2- and 25-fold, respectively, by feeding BSA at these two concentrations compared with no addition. Comparing the two systems, the increase in the antibody production rate achieved with the hollow-fiber system was threefold greater than that in the perfusion culture system with the same concentration of BSA feeding. (c) 1995 John Wiley & Sons, Inc. PMID:18623537

  3. Estimation of ozone with total ozone portable spectroradiometer instruments. I. Theoretical model and error analysis

    NASA Astrophysics Data System (ADS)

    Flynn, Lawrence E.; Labow, Gordon J.; Beach, Robert A.; Rawlins, Michael A.; Flittner, David E.

    1996-10-01

    Inexpensive devices to measure solar UV irradiance are available to monitor atmospheric ozone, for example, total ozone portable spectroradiometers (TOPS instruments). A procedure to convert these measurements into ozone estimates is examined. For well-characterized filters with 7-nm FWHM bandpasses, the method provides ozone values (from 304- and 310-nm channels) with less than 0.4 error attributable to inversion of the theoretical model. Analysis of sensitivity to model assumptions and parameters yields estimates of 3 bias in total ozone results with dependence on total ozone and path length. Unmodeled effects of atmospheric constituents and instrument components can result in additional 2 errors.

  4. Contribution of low vapor pressure-volatile organic compounds (LVP-VOCs) from consumer products to ozone formation in urban atmospheres

    NASA Astrophysics Data System (ADS)

    Shin, Hyeong-Moo; McKone, Thomas E.; Bennett, Deborah H.

    2015-05-01

    Because recent laboratory testing indicates that some low vapor pressure-volatile organic compounds (LVP-VOC) solvents readily evaporate at ambient conditions, LVP-VOCs used in some consumer product formulations may contribute to ozone formation. The goal of this study is to determine the fraction of LVP-VOCs available for ozone formation from the use of consumer products for two hypothetical emissions. This study calculates and compares the fraction of consumed product available for ozone formation as a result of (a) volatilization to air during use and (b) down-the-drain disposal. The study also investigates the impact of different modes of releases on the overall fraction available in ambient air for ozone formation. For the portion of the LVP-VOCs volatilized to air during use, we applied a multi-compartment mass-balance model to track the fate of emitted LVP-VOCs in a multimedia urban environment. For the portion of the LVP-VOCs disposed down the drain, we used a wastewater treatment plant (WWTP) fate model to predict the emission rates of LVP-VOCs to ambient air at WWTPs or at the discharge zone of the facilities and then used these results as emissions in the multimedia urban environment model. In a WWTP, the LVP-VOCs selected in this study are primarily either biodegraded or removed via sorption to sludge depending on the magnitude of the biodegradation half-life and the octanol-water partition coefficient. Less than 0.2% of the LVP-VOCs disposed down the drain are available for ozone formation. In contrast, when the LVP-VOC in a consumer product is volatilized from the surface to which it has been applied, greater than 90% is available for photochemical reactions either at the source location or in the downwind areas. Comparing results from these two modes of releases allows us to understand the importance of determining the fraction of LVP-VOCs volatilized versus disposed down the drain when the product is used by consumers. The results from this study

  5. Ozone variability

    NASA Astrophysics Data System (ADS)

    Duetsch, H. U.

    1983-09-01

    The annual and long-term variations in the atmospheric ozone layer were examined on the basis of 55 yr of data taken at Aroya, Switzerland and 25 yr of data gathered by the global ozone network. Attention was given to annual and biennial variations, which showed that the midlatitude peak concentration was affected by a quasi-biennial variation of the tropical stratospheric circulation. Smaller scale circulation patterns were dominant in the lower stratosphere, although an observed negative trend of the total ozone was equally distributed between the troposphere and 24 km altitude. The global ozone increase detected in the 1960s was possible due to general circulation alterations, but may also have been influenced by injection of NO(x) into the atmosphere during atomic bomb testing.

  6. Determination of photodegradation and ozonation by products of linear alkylbenzene sulfonates by liquid chromatography and ion chromatography under controlled laboratory experiments.

    PubMed

    Fernández, J; Riu, J; Garíca-Calvo, E; Rodríguez, A; Fernández-Alba, A R; Barceló, D

    2004-09-01

    A Suntest solar simulator with arc xenon lamp was used to irradiate pure linear alkylbenzene sulfonates (LAS) standard and some commercial LAS solutions. The ozonation treatment was carried out in a pilot plant air-lift type reactor. Kinetic degradation curves were obtained showing an apparent first order reaction in both cases. Extraction and preconcentration of samples was carried out by off-line SPE using polymeric an RP-18 cartridges with recoveries varying from 77 to 93% for the LAS compounds. For LC chromatographic elution of LAS and degradation products an ion pair based on 5mM triethylamine and 5nM acetic acid had to the acetonitrile-water or methanol-water mobile phases. Fluorescence detection was achieved at 225 and 295nm as excitation and emission radiation wavelength, respectively. Degradation by products were identified by liquid chromatography electrospray mass spectrometry detection (LC-ESI-MS). Ion chromatography (IC) was used to analyze refractory species such as oxalate, formate and acetate ions which were present in the treated solution even after 3h of ozone treatment. The LAS mixture was almost totally degraded in less than 20min using O(3)/H(2)O(2), the reaction being faster than in the case of catalyzed photodecomposition. TOC removal reached 84% after 3h of ozonation process. PMID:18969570

  7. Tropospheric Ozone Over a Tropical Atlantic Station in the Northern Hemisphere: Paramaribo, Surinam (6 deg N, 55 deg W)

    NASA Technical Reports Server (NTRS)

    Peters, W.; Krol, M. C.; Fortuin, J. P. F.; Kelder, H. M.; Thompson, A. M.; Becker, C. R.; Lelieveld, J.; Crutzen, P. J.

    2003-01-01

    We present an analysis of 2.5 years of weekly ozone soundings conducted at a new monitoring station in Paramaribo, Surinam (6 deg N,55 deg W). This is currently one of only three ozone sounding stations in the northern hemisphere (NH) tropics, and the only one in the equatorial Atlantic region. Paramaribo is part of the Southern Hemisphere ADditional Ozone Sounding program (SHADOZ). Due to its position close to the equator, the Inter Tropical Convergence Zone (ITCZ) passes over Paramaribo twice per year, which results in a semi-annual seasonality of many parameters including relative humidity and ozone. The dataset from Paramaribo is used to: (1) evaluate ozone variability relative to precipitation, atmospheric circulation patterns and biomass burning; (2) contrast ozone at the NH equatorial Atlantic with that at nearby southern hemisphere (SH) stations Natal (6 deg S,35 deg W) and Ascension (8 deg S,14 deg W); (3) compare the seasonality of tropospheric ozone with a satellite-derived ozone product: Tropical Tropospheric Ozone Columns from the Modified Residual method (MR-TTOC). We find that Paramaribo is a distinctly Atlantic station. Despite its position north of the equator, it resembles nearby SH stations during most of the year. Transport patterns in the lower and middle troposphere during February and March differ from SH stations, which leads to a seasonality of ozone with two maxima. MR-TTOC over Paramaribo does not match the observed seasonality of ozone due to the use of a SH ozone sonde climatology in the MR method. The Paramaribo ozone record is used to suggest an improvement for northern hemisphere MR-TTOC retrievals. We conclude that station Paramaribo shows unique features in the region, and clearly adds new information to the existing SHADOZ record.

  8. The oleic acid-ozone heterogeneous reaction system: products, kinetics, secondary chemistry, and atmospheric implications of a model system a review

    NASA Astrophysics Data System (ADS)

    Zahardis, J.; Petrucci, G. A.

    2006-11-01

    The heterogeneous processing of organic aerosols by trace oxidants has many implications to atmospheric chemistry and climate regulation. This review covers a model heterogeneous reaction system (HRS): the oleic acid-ozone HRS and other reaction systems featuring fatty acids, and their derivatives. The analysis of the primary products of ozonolysis (azelaic acid, nonanoic acid, 9-oxononanoic acid, nonanal) is described. Anomalies in the relative product yields are noted and explained by the observation of secondary chemical reactions. The secondary reaction products arising from reactive Criegee intermediates are mainly peroxidic, notably secondary ozonides and α-acyloxyalkyl hydroperoxide polymers. These highly oxygenated products are of low volatility a