Sample records for stringent nitrogen oxides

  1. On-road emissions of light-duty vehicles in europe.

    PubMed

    Weiss, Martin; Bonnel, Pierre; Hummel, Rudolf; Provenza, Alessio; Manfredi, Urbano

    2011-10-01

    For obtaining type approval in the European Union, light-duty vehicles have to comply with emission limits during standardized laboratory emissions testing. Although emission limits have become more stringent in past decades, light-duty vehicles remain an important source of nitrogen oxides and carbon monoxide emissions in Europe. Furthermore, persisting air quality problems in many urban areas suggest that laboratory emissions testing may not accurately capture the on-road emissions of light-duty vehicles. To address this issue, we conduct the first comprehensive on-road emissions test of light-duty vehicles with state-of-the-art Portable Emission Measurement Systems. We find that nitrogen oxides emissions of gasoline vehicles as well as carbon monoxide and total hydrocarbon emissions of both diesel and gasoline vehicles generally remain below the respective emission limits. By contrast, nitrogen oxides emissions of diesel vehicles (0.93 ± 0.39 grams per kilometer [g/km]), including modern Euro 5 diesel vehicles (0.62 ± 0.19 g/km), exceed emission limits by 320 ± 90%. On-road carbon dioxide emissions surpass laboratory emission levels by 21 ± 9%, suggesting that the current laboratory emissions testing fails to accurately capture the on-road emissions of light-duty vehicles. Our findings provide the empirical foundation for the European Commission to establish a complementary emissions test procedure for light-duty vehicles. This procedure could be implemented together with more stringent Euro 6 emission limits in 2014. The envisaged measures should improve urban air quality and provide incentive for innovation in the automotive industry.

  2. Proteome analysis of yeast response to various nutrient limitations

    PubMed Central

    Kolkman, Annemieke; Daran-Lapujade, Pascale; Fullaondo, Asier; Olsthoorn, Maurien M A; Pronk, Jack T; Slijper, Monique; Heck, Albert J R

    2006-01-01

    We compared the response of Saccharomyces cerevisiae to carbon (glucose) and nitrogen (ammonia) limitation in chemostat cultivation at the proteome level. Protein levels were differentially quantified using unlabeled and 15N metabolically labeled yeast cultures. A total of 928 proteins covering a wide range of isoelectric points, molecular weights and subcellular localizations were identified. Stringent statistical analysis identified 51 proteins upregulated in response to glucose limitation and 51 upregulated in response to ammonia limitation. Under glucose limitation, typical glucose-repressed genes encoding proteins involved in alternative carbon source utilization, fatty acids β-oxidation and oxidative phosphorylation displayed an increased protein level. Proteins upregulated in response to nitrogen limitation were mostly involved in scavenging of alternative nitrogen sources and protein degradation. Comparison of transcript and protein levels clearly showed that upregulation in response to glucose limitation was mainly transcriptionally controlled, whereas upregulation in response to nitrogen limitation was essentially controlled at the post-transcriptional level by increased translational efficiency and/or decreased protein degradation. These observations underline the need for multilevel analysis in yeast systems biology. PMID:16738570

  3. Ultrasound-assisted oxidative desulfurization and denitrogenation of liquid hydrocarbon fuels: A critical review.

    PubMed

    Ja'fari, Mahsa; Ebrahimi, Seyedeh Leila; Khosravi-Nikou, Mohammad Reza

    2018-01-01

    Nowadays, a continuously worldwide concern for development of process to produce ultra-low sulfur and nitrogen fuels have been emerged. Typical hydrodesulfurization and hydrodenitrogenation technology deals with important difficulties such as high pressure and temperature operating condition, failure to treat some recalcitrant compounds and limitations to meet the stringent environmental regulations. In contrary an advanced oxidation process that is ultrasound assisted oxidative desulfurization and denitrogenation satisfies latest environmental regulations in much milder conditions with more efficiency. The present work deals with a comprehensive review on findings and development in the ultrasound assisted oxidative desulfurization and denitrogenation (UAOD) during the last decades. The role of individual parameters namely temperature, residence time, ultrasound power and frequency, pH, initial concentration and types of sulfur and nitrogen compounds on the efficiency are described. What's more another treatment properties that is role of phase transfer agent (PTA) and solvents of extraction step, reaction kinetics, mechanism of the ultrasound, fuel properties and recovery in UAOD are reviewed. Finally, the required future works to mature this technology are suggested. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Technology innovations and experience curves for nitrogen oxides control technologies.

    PubMed

    Yeh, Sonia; Rubin, Edward S; Taylor, Margaret R; Hounshell, David A

    2005-12-01

    This paper reviews the regulatory history for nitrogen oxides (NOx) pollutant emissions from stationary sources, primarily in coal-fired power plants. Nitrogen dioxide (NO2) is one of the six criteria pollutants regulated by the 1970 Clean Air Act where National Ambient Air Quality Standards were established to protect public health and welfare. We use patent data to show that in the cases of Japan, Germany, and the United States, innovations in NOx control technologies did not occur until stringent government regulations were in place, thus "forcing" innovation. We also demonstrate that reductions in the capital and operation and maintenance (O&M) costs of new generations of high-efficiency NOx control technologies, selective catalytic reduction (SCR), are consistently associated with the increasing adoption of the control technology: the so-called learning-by-doing phenomena. The results show that as cumulative world coal-fired SCR capacity doubles, capital costs decline to approximately 86% and O&M costs to 58% of their original values. The observed changes in SCR technology reflect the impact of technological advance as well as other factors, such as market competition and economies of scale.

  5. Numerical Research of Nitrogen Oxides Formation for Justification of Modernization of P-49 Nazarovsky State District Power Plant Boiler on the Low-temperature Swirl Technology of Burning

    NASA Astrophysics Data System (ADS)

    Trinchenko, A. A.; Paramonov, A. P.; Skouditskiy, V. E.; Anoshin, R. G.

    2017-11-01

    Compliance with increasingly stringent normative requirements to the level of pollutants emissions when using organic fuel in the energy sector as a main source of heat, demands constant improvement of the boiler and furnace equipment and the power equipment in general. The requirements of the current legislation in the field of environmental protection prescribe compliance with established emission standards for both new construction and the improvement of energy equipment. The paper presents the results of numerical research of low-temperature swirl burning in P-49 Nazarovsky state district power plant boiler. On the basis of modern approaches of the diffusion and kinetic theory of burning and the analysis physical and chemical processes of a fuel chemically connected energy transition in thermal, generation and transformation of gas pollutants, the technological method of nitrogen oxides decomposition on the surface of carbon particles with the formation of environmentally friendly carbonic acid and molecular nitrogen is considered during the work of low-temperature swirl furnace. With the use of the developed model, methodology and computer program, variant calculations of the combustion process were carried out and a quantitative estimate of the emission level of the nitrogen oxides of the boiler being modernized. The simulation results the and the experimental data obtained during the commissioning and balance tests of the P-49 boiler with a new furnace are confirmed that the organization of swirl combustion has allowed to increase the efficiency of work, to reduce slagging, to significantly reduce nitrogen oxide emissions, to improve ignition and burnout of fuel.

  6. Nitrogen stress response and stringent response are coupled in Escherichia coli

    PubMed Central

    Brown, Daniel R.; Barton, Geraint; Pan, Zhensheng; Buck, Martin; Wigneshweraraj, Sivaramesh

    2014-01-01

    Assimilation of nitrogen is an essential process in bacteria. The nitrogen regulation stress response is an adaptive mechanism used by nitrogen-starved Escherichia coli to scavenge for alternative nitrogen sources and requires the global transcriptional regulator NtrC. In addition, nitrogen-starved E. coli cells synthesize a signal molecule, guanosine tetraphosphate (ppGpp), which serves as an effector molecule of many processes including transcription to initiate global physiological changes, collectively termed the stringent response. The regulatory mechanisms leading to elevated ppGpp levels during nutritional stresses remain elusive. Here, we show that transcription of relA, a key gene responsible for the synthesis of ppGpp, is activated by NtrC during nitrogen starvation. The results reveal that NtrC couples these two major bacterial stress responses to manage conditions of nitrogen limitation, and provide novel mechanistic insights into how a specific nutritional stress leads to elevating ppGpp levels in bacteria. PMID:24947454

  7. Effect of inlet temperature on the performance of a catalytic reactor. [air pollution control

    NASA Technical Reports Server (NTRS)

    Anderson, D. N.

    1978-01-01

    A 12 cm diameter by 15 cm long catalytic reactor was tested with No. 2 diesel fuel in a combustion test rig at inlet temperatures of 700, 800, 900, and 1000 K. Other test conditions included pressures of 3 and 6 x 10 to the 5th power Pa, reference velocities of 10, 15, and 20 m/s, and adiabatic combustion temperatures in the range 1100 to 1400 K. The combustion efficiency was calculated from measurements of carbon monoxide and unburned hydrocarbon emissions. Nitrogen oxide emissions and reactor pressure drop were also measured. At a reference velocity of 10 m/s, the CO and unburned hydrocarbons emissions, and, therefore, the combustion efficiency, were independent of inlet temperature. At an inlet temperature of 1000 K, they were independent of reference velocity. Nitrogen oxides emissions resulted from conversion of the small amount (135 ppm) of fuel-bound nitrogen in the fuel. Up to 90 percent conversion was observed with no apparent effect of any of the test variables. For typical gas turbine operating conditions, all three pollutants were below levels which would permit the most stringent proposed automotive emissions standards to be met.

  8. Reducing secondary organic aerosol formation from gasoline vehicle exhaust

    PubMed Central

    Zhao, Yunliang; Saleh, Rawad; Presto, Albert A.; Gordon, Timothy D.; Drozd, Greg T.; Goldstein, Allen H.; Robinson, Allen L.

    2017-01-01

    On-road gasoline vehicles are a major source of secondary organic aerosol (SOA) in urban areas. We investigated SOA formation by oxidizing dilute, ambient-level exhaust concentrations from a fleet of on-road gasoline vehicles in a smog chamber. We measured less SOA formation from newer vehicles meeting more stringent emissions standards. This suggests that the natural replacement of older vehicles with newer ones that meet more stringent emissions standards should reduce SOA levels in urban environments. However, SOA production depends on both precursor concentrations (emissions) and atmospheric chemistry (SOA yields). We found a strongly nonlinear relationship between SOA formation and the ratio of nonmethane organic gas to oxides of nitrogen (NOx) (NMOG:NOx), which affects the fate of peroxy radicals. For example, changing the NMOG:NOx from 4 to 10 ppbC/ppbNOx increased the SOA yield from dilute gasoline vehicle exhaust by a factor of 8. We investigated the implications of this relationship for the Los Angeles area. Although organic gas emissions from gasoline vehicles in Los Angeles are expected to fall by almost 80% over the next two decades, we predict no reduction in SOA production from these emissions due to the effects of rising NMOG:NOx on SOA yields. This highlights the importance of integrated emission control policies for NOx and organic gases. PMID:28630318

  9. Mobile sources critical review: 1998 NARSTO assessment

    NASA Astrophysics Data System (ADS)

    Sawyer, R. F.; Harley, R. A.; Cadle, S. H.; Norbeck, J. M.; Slott, R.; Bravo, H. A.

    Mobile sources of air pollutants encompass a range of vehicle, engine, and fuel combinations. They emit both of the photochemical ozone precursors, hydrocarbons and oxides of nitrogen. The most important source of hydrocarbons and oxides of nitrogen are light- and heavy-duty on-road vehicles and heavy-duty off-road vehicles, utilizing spark and compression ignition engines burning gasoline and diesel respectively. Fuel consumption data provide a convenient starting point for assessing current and future emissions. Modern light-duty, gasoline vehicles when new have very low emissions. The in-use fleet, due largely to emissions from a small "high emitter" fraction, has significantly larger emissions. Hydrocarbons and carbon monoxide are higher than reported in current inventories. Other gasoline powered mobile sources (motorcycles, recreational vehicles, lawn, garden, and utility equipment, and light aircraft) have high emissions on a per quantity of fuel consumed basis, but their contribution to total emissions is small. Additional uncertainties in spatial and temporal distribution of emissions exist. Heavy-duty diesel vehicles are becoming the dominant mobile source of oxides of nitrogen. Oxides of nitrogen emissions may be greater than reported in current inventories, but the evidence for this is mixed. Oxides of nitrogen emissions on a fuel-consumed basis are much greater from diesel mobile sources than from gasoline mobile sources. This is largely the result of stringent control of gasoline vehicle emissions and a lesser (heavy-duty trucks) or no control (construction equipment, locomotives, ships) of heavy-duty mobile sources. The use of alternative fuels, natural gas, propane, alcohols, and oxygenates in motor vehicles is increasing but remains small. Vehicles utilizing these fuels can be but are not necessarily cleaner than their gasoline or diesel counterparts. Historical vehicle kilometers traveled growth rates of about 2% annually in both the United States and Canada will slow somewhat to about 1.5%. Mexican growth rates are expected to be greater. Fuel consumption growth in recent years of about 1.4% annually is projected to continue as slowing gains in fuel economy from fleet turnover are more than offset by growth and the increasing number of Sport Utility Vehicles. This growth also will erode the emissions reductions resulting from cleaner new vehicles and fuels. Uncertainties in these projections are high and affected by economic activity, demographics, and the effectiveness of emissions control programs — especially those for reducing in-use emissions.

  10. Nitrogen polishing in a fully anoxic anammox MBBR treating mainstream nitritation-denitritation effluent.

    PubMed

    Regmi, Pusker; Holgate, Becky; Miller, Mark W; Park, Hongkeun; Chandran, Kartik; Wett, Bernhard; Murthy, Sudhir; Bott, Charles B

    2016-03-01

    As nitrogen discharge limits are becoming more stringent, short-cut nitrogen systems and tertiary nitrogen polishing steps are gaining popularity. For partial nitritation or nitritation-denitritation systems, anaerobic ammonia oxidation (anammox) polishing may be feasible to remove residual ammonia and nitrite from the effluent. Nitrogen polishing of mainstream nitritation-denitritation system effluent via anammox was studied at 25°C in a fully anoxic moving bed bioreactor (MBBR) (V = 0.45 m(3) ) over 385 days. Unlike other anammox based processes, a very fast startup of anammox MBBR was demonstrated, despite nitrite limited feeding conditions (influent nitrite = 0.7 ± 0.59 mgN/L, ammonia = 6.13 ± 2.86 mgN/L, nitrate = 3.41 ± 1.92 mgN/L). The nitrogen removal performance was very stable within a wide range of nitrogen inputs. Anammox bacteria (AMX) activity up to 1 gN/m(2) /d was observed which is comparable to other biofilm-based systems. It is generally believed that nitrate production limits nitrogen removal through AMX metabolism. However, in this study, anammox MBBR demonstrated ammonia, nitrite, and nitrate removal at limited chemical oxygen demand (COD) availability. AMX and heterotrophs contributed to 0.68 ± 0.17 and 0.32 ± 0.17 of TIN removal, respectively. It was speculated that nitrogen removal might be aided by denitratation which could be due to heterotrophs or the recently discovered ability for AMX to use short-chain fatty acids to reduce nitrate to nitrite. This study demonstrates the feasibility of anammox nitrogen polishing in an MBBR is possible for nitritation-denitration systems. © 2015 Wiley Periodicals, Inc.

  11. On-road, in-use gaseous emission measurements by remote sensing of school buses equipped with diesel oxidation catalysts and diesel particulate filters.

    PubMed

    Burgard, Daniel A; Provinsal, Melissa N

    2009-12-01

    A remote sensing device was used to obtain on-road and in-use gaseous emission measurements from three fleets of schools buses at two locations in Washington State. This paper reports each fleet's carbon monoxide (CO), hydrocarbon (HC), nitric oxide (NO), and nitrogen dioxide (NO2) mean data. The fleets represent current emission retrofit technologies, such as diesel particulate filters and diesel oxidation catalysts, and a control fleet. This study shows that CO and HC emissions decrease with the use of either retrofit technology when compared with control buses of the same initial emission standards. The CO and HC emission reductions are consistent with published U.S. Environmental Protection Agency verified values. The total oxides of nitrogen (NOx), NO, and the NO2/NOx ratio all increase with each retrofit technology when compared with control buses. As was expected, the diesel particulate filters emitted significantly higher levels of NO2 than the control fleet because of the intentional conversion of NO to NO2 by these systems. Most prior research suggests that NOx emissions are unaffected by the retrofits; however, these previous studies have not included measurements from retrofit devices on-road and after nearly 5 yr of use. Two 2006 model-year buses were also measured. These vehicles did not have retrofit devices but were built to more stringent new engine standards. Reductions in HCs and NOx were observed for these 2006 vehicles in comparison to other non-retrofit earlier model-year vehicles.

  12. Screening and identification of aerobic denitrifiers

    NASA Astrophysics Data System (ADS)

    Shao, K.; Deng, H. M.; Chen, Y. T.; Zhou, H. J.; Yan, G. X.

    2016-08-01

    With the standards of the effluent quality more stringent, it becomes a quite serious problem for municipalities and industries to remove nitrogen from wastewater. Bioremediation is a potential method for the removal of nitrogen and other pollutants because of its high efficiency and low cost. Seven predominant aerobic denitrifiers were screened and characterized from the activated sludge in the CAST unit. Some of these strains removed 87% nitrate nitrogen at least. Based on their phenotypic and phylogenetic characteristics, the isolates were identified as the genera of Ralstonia, Achromobacter, Aeromonas and Enterobacter.

  13. Global gene expression during stringent response in Corynebacterium glutamicum in presence and absence of the rel gene encoding (p)ppGpp synthase

    PubMed Central

    Brockmann-Gretza, Olaf; Kalinowski, Jörn

    2006-01-01

    Background The stringent response is the initial reaction of microorganisms to nutritional stress. During stringent response the small nucleotides (p)ppGpp act as global regulators and reprogram bacterial transcription. In this work, the genetic network controlled by the stringent response was characterized in the amino acid-producing Corynebacterium glutamicum. Results The transcriptome of a C. glutamicum rel gene deletion mutant, unable to synthesize (p)ppGpp and to induce the stringent response, was compared with that of its rel-proficient parent strain by microarray analysis. A total of 357 genes were found to be transcribed differentially in the rel-deficient mutant strain. In a second experiment, the stringent response was induced by addition of DL-serine hydroxamate (SHX) in early exponential growth phase. The time point of the maximal effect on transcription was determined by real-time RT-PCR using the histidine and serine biosynthetic genes. Transcription of all of these genes reached a maximum at 10 minutes after SHX addition. Microarray experiments were performed comparing the transcriptomes of SHX-induced cultures of the rel-proficient strain and the rel mutant. The differentially expressed genes were grouped into three classes. Class A comprises genes which are differentially regulated only in the presence of an intact rel gene. This class includes the non-essential sigma factor gene sigB which was upregulated and a large number of genes involved in nitrogen metabolism which were downregulated. Class B comprises genes which were differentially regulated in response to SHX in both strains, independent of the rel gene. A large number of genes encoding ribosomal proteins fall into this class, all being downregulated. Class C comprises genes which were differentially regulated in response to SHX only in the rel mutant. This class includes genes encoding putative stress proteins and global transcriptional regulators that might be responsible for the complex transcriptional patterns detected in the rel mutant when compared directly with its rel-proficient parent strain. Conclusion In C. glutamicum the stringent response enfolds a fast answer to an induced amino acid starvation on the transcriptome level. It also showed some significant differences to the transcriptional reactions occuring in Escherichia coli and Bacillus subtilis. Notable are the rel-dependent regulation of the nitrogen metabolism genes and the rel-independent regulation of the genes encoding ribosomal proteins. PMID:16961923

  14. Performance of a peroxide-based cetane improvement additive in different diesel fuels

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nandi, M.K.; Jacobs, D.C.; Liotta, F.J. Jr.

    The implementation of stringent diesel engine emissions regulations is growing worldwide. The use of high cetane diesel fuels is a cost-effective option that can be used to reduce engine emissions. A direct comparison of heavy-duty diesel engine emissions for three different low sulfur diesel fuels treated with di-t-butyl peroxide and 2-ethylhexyl nitrate, at the same cetane level, was evaluated. Both the peroxide and the nitrate cetane improvement additive significantly reduced all regulated and unregulated emissions including the oxides of nitrogen (NOx) emission. Di-t-butyl peroxide shows a small advantage over ethylhexyl nitrate in reducing NOx in all the three fuels. Compatibilitymore » of the peroxide and the nitrate additives, when mixed in a fuel blend, has been demonstrated by cetane response and engine emissions for the fuel blend. 13 refs., 2 figs., 9 tabs.« less

  15. Trend and future of diesel engine: Development of high efficiency and low emission low temperature combustion diesel engine

    NASA Astrophysics Data System (ADS)

    Ho, R. J.; Yusoff, M. Z.; Palanisamy, K.

    2013-06-01

    Stringent emission policy has put automotive research & development on developing high efficiency and low pollutant power train. Conventional direct injection diesel engine with diffused flame has reached its limitation and has driven R&D to explore other field of combustion. Low temperature combustion (LTC) and homogeneous charge combustion ignition has been proven to be effective methods in decreasing combustion pollutant emission. Nitrogen Oxide (NOx) and Particulate Matter (PM) formation from combustion can be greatly suppressed. A review on each of method is covered to identify the condition and processes that result in these reductions. The critical parameters that allow such combustion to take place will be highlighted and serves as emphasis to the direction of developing future diesel engine system. This paper is written to explore potential of present numerical and experimental methods in optimizing diesel engine design through adoption of the new combustion technology.

  16. Nitrogen Oxide Emission, Economic Growth and Urbanization in China: a Spatial Econometric Analysis

    NASA Astrophysics Data System (ADS)

    Zhou, Zhimin; Zhou, Yanli; Ge, Xiangyu

    2018-01-01

    This research studies the nexus of nitrogen oxide emissions and economic development/urbanization. Under the environmental Kuznets curve (EKC) hypothesis, we apply the analysis technique of spatial panel data in the STIRPAT framework, and thus obtain the estimated impacts of income/urbanization on nitrogen oxide emission systematically. The empirical findings suggest that spatial dependence on nitrogen oxide emission distribution exist at provincial level, and the inverse N-shape EKC describes both income-nitrogen oxide and urbanization-nitrogen oxide nexuses. In addition, some well-directed policy advices are made to reduce the nitrogen oxide emission in future.

  17. Experimental study on the particulate matter and nitrogenous compounds from diesel engine retrofitted with DOC+CDPF+SCR

    NASA Astrophysics Data System (ADS)

    Zhang, Yunhua; Lou, Diming; Tan, Piqiang; Hu, Zhiyuan

    2018-03-01

    The increasingly stringent emission regulations will mandate the retrofit of after-treatment devices for in-use diesel vehicles, in order to reduce their substantial particulate matter and nitrogen oxides (NOX) emissions. In this paper, a combination of DOC (diesel oxidation catalyst), CDPF (catalytic diesel particulate filter) and SCR (selective catalytic reduction) retrofit for a heavy-duty diesel engine was employed to perform experiment on the engine test bench to evaluate the effects on the particulate matter emissions including particle number (PN), particle mass (PM), particle size distributions and nitrogenous compounds emissions including NOX, nitrogen dioxide (NO2)/NOX, nitrous oxide (N2O) and ammonia (NH3) slip. In addition, the urea injection was also of our concern. The results showed that the DOC+CDPF+SCR retrofit almost had no adverse effect on the engine power and fuel consumption. Under the test loads, the upstream DOC and CDPF reduced the PN and PM by an average of 91.6% and 90.9%, respectively. While the downstream SCR brought about an average decrease of 85% NOX. Both PM and NOX emission factors based on this retrofit were lower than China-Ⅳ limits (ESC), and even lower than China-Ⅴ limits (ESC) at medium and high loads. The DOC and CDPF changed the particle size distributions, leading to the increase in the proportion of accumulation mode particles and the decrease in the percentage of nuclear mode particles. This indicates that the effect of DOC and CDPF on nuclear mode particles was better than that of accumulation mode ones. The upstream DOC could increase the NO2/NOX ratio to 40%, higher NO2/NOX ratio improved the efficiency of CDPF and SCR. Besides, the N2O emission increased by an average of 2.58 times after the retrofit and NH3 slip occurred with the average of 26.7 ppm. The rate of urea injection was roughly equal to 8% of the fuel consumption rate. The DOC+CDPF+SCR retrofit was proved a feasible and effective measurement in terms of reducing particulate emissions and NOX simultaneously for in-use engine. However, it also resulted in higher N2O emission, NH3 slip as well as urea injecting strategy problem which should be of further concern.

  18. 40 CFR 86.318-79 - Oxides of nitrogen analyzer specifications.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Oxides of nitrogen analyzer... Procedures § 86.318-79 Oxides of nitrogen analyzer specifications. (a) Oxides of nitrogen are to be measured....327. (b) Option. The oxides of nitrogen may be measured with an NDIR analyzer system that meets the...

  19. 40 CFR 86.318-79 - Oxides of nitrogen analyzer specifications.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Oxides of nitrogen analyzer... Procedures § 86.318-79 Oxides of nitrogen analyzer specifications. (a) Oxides of nitrogen are to be measured....327. (b) Option. The oxides of nitrogen may be measured with an NDIR analyzer system that meets the...

  20. 40 CFR 86.318-79 - Oxides of nitrogen analyzer specifications.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Oxides of nitrogen analyzer... Procedures § 86.318-79 Oxides of nitrogen analyzer specifications. (a) Oxides of nitrogen are to be measured....327. (b) Option. The oxides of nitrogen may be measured with an NDIR analyzer system that meets the...

  1. Nox control for high nitric oxide concentration flows through combustion-driven reduction

    DOEpatents

    Yeh, James T.; Ekmann, James M.; Pennline, Henry W.; Drummond, Charles J.

    1989-01-01

    An improved method for removing nitrogen oxides from concentrated waste gas streams, in which nitrogen oxides are ignited with a carbonaceous material in the presence of substoichiometric quantities of a primary oxidant, such as air. Additionally, reductants may be ignited along with the nitrogen oxides, carbonaceous material and primary oxidant to achieve greater reduction of nitrogen oxides. A scrubber and regeneration system may also be included to generate a concentrated stream of nitrogen oxides from flue gases for reduction using this method.

  2. The position of gas turbine power plants with respect to the emission of nitrogen oxides by fossil-fueled energy installations

    NASA Technical Reports Server (NTRS)

    Kaiser, E.

    1977-01-01

    The amount of nitrogen oxides introduced into the atmosphere by gas turbines is very significant in relation to the total amount of nitrogen oxide emissions produced by chemical installations and combustion engines. Turbine manufacturers are therefore working to develop combustion chambers with sufficiently low nitrogen oxide emission concentrations. Attention is given to aspects of nitrogen oxide formation in gas turbines, the parameters which determine this formation, and suitable approaches to reducing nitrogen oxide emissions.

  3. 40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). 50.11 Section... quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). (a) The level of the national primary annual ambient air quality standard for oxides of nitrogen is 53 parts per billion (ppb...

  4. 40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). 50.11 Section... quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). (a) The level of the national primary annual ambient air quality standard for oxides of nitrogen is 53 parts per billion (ppb...

  5. 40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). 50.11 Section... quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). (a) The level of the national primary annual ambient air quality standard for oxides of nitrogen is 53 parts per billion (ppb...

  6. Cholera Toxin Production during Anaerobic Trimethylamine N-Oxide Respiration Is Mediated by Stringent Response in Vibrio cholerae*

    PubMed Central

    Oh, Young Taek; Park, Yongjin; Yoon, Mi Young; Bari, Wasimul; Go, Junhyeok; Min, Kyung Bae; Raskin, David M.; Lee, Kang-Mu; Yoon, Sang Sun

    2014-01-01

    As a facultative anaerobe, Vibrio cholerae can grow by anaerobic respiration. Production of cholera toxin (CT), a major virulence factor of V. cholerae, is highly promoted during anaerobic growth using trimethylamine N-oxide (TMAO) as an alternative electron acceptor. Here, we investigated the molecular mechanisms of TMAO-stimulated CT production and uncovered the crucial involvement of stringent response in this process. V. cholerae 7th pandemic strain N16961 produced a significantly elevated level of ppGpp, the bacterial stringent response alarmone, during anaerobic TMAO respiration. Bacterial viability was impaired, and DNA replication was also affected under the same growth condition, further suggesting that stringent response is induced. A ΔrelA ΔspoT ppGpp overproducer strain produced an enhanced level of CT, whereas anaerobic growth via TMAO respiration was severely inhibited. In contrast, a ppGpp-null strain (ΔrelA ΔspoT ΔrelV) grew substantially better, but produced no CT, suggesting that CT production and bacterial growth are inversely regulated in response to ppGpp accumulation. Bacterial capability to produce CT was completely lost when the dksA gene, which encodes a protein that works cooperatively with ppGpp, was deleted. In the ΔdksA mutant, stringent response growth inhibition was alleviated, further supporting the inverse regulation of CT production and anaerobic growth. In vivo virulence of ΔrelA ΔspoT ΔrelV or ΔdksA mutants was significantly attenuated. The ΔrelA ΔspoT mutant maintained virulence when infected with exogenous TMAO despite its defective growth. Together, our results reveal that stringent response is activated under TMAO-stimulated anaerobic growth, and it regulates CT production in a growth-dependent manner in V. cholerae. PMID:24648517

  7. 40 CFR 86.523-78 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Oxides of nitrogen analyzer... Emission Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.523-78 Oxides of nitrogen... nitrogen are measured, the chemiluminescent oxides of nitrogen analyzer must be checked for NO2 to NO...

  8. 40 CFR 86.523-78 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Oxides of nitrogen analyzer... Emission Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.523-78 Oxides of nitrogen... nitrogen are measured, the chemiluminescent oxides of nitrogen analyzer must be checked for NO2 to NO...

  9. Rapid cycling of reactive nitrogen in the marine boundary layer.

    PubMed

    Ye, Chunxiang; Zhou, Xianliang; Pu, Dennis; Stutz, Jochen; Festa, James; Spolaor, Max; Tsai, Catalina; Cantrell, Christopher; Mauldin, Roy L; Campos, Teresa; Weinheimer, Andrew; Hornbrook, Rebecca S; Apel, Eric C; Guenther, Alex; Kaser, Lisa; Yuan, Bin; Karl, Thomas; Haggerty, Julie; Hall, Samuel; Ullmann, Kirk; Smith, James N; Ortega, John; Knote, Christoph

    2016-04-28

    Nitrogen oxides are essential for the formation of secondary atmospheric aerosols and of atmospheric oxidants such as ozone and the hydroxyl radical, which controls the self-cleansing capacity of the atmosphere. Nitric acid, a major oxidation product of nitrogen oxides, has traditionally been considered to be a permanent sink of nitrogen oxides. However, model studies predict higher ratios of nitric acid to nitrogen oxides in the troposphere than are observed. A 'renoxification' process that recycles nitric acid into nitrogen oxides has been proposed to reconcile observations with model studies, but the mechanisms responsible for this process remain uncertain. Here we present data from an aircraft measurement campaign over the North Atlantic Ocean and find evidence for rapid recycling of nitric acid to nitrous acid and nitrogen oxides in the clean marine boundary layer via particulate nitrate photolysis. Laboratory experiments further demonstrate the photolysis of particulate nitrate collected on filters at a rate more than two orders of magnitude greater than that of gaseous nitric acid, with nitrous acid as the main product. Box model calculations based on the Master Chemical Mechanism suggest that particulate nitrate photolysis mainly sustains the observed levels of nitrous acid and nitrogen oxides at midday under typical marine boundary layer conditions. Given that oceans account for more than 70 per cent of Earth's surface, we propose that particulate nitrate photolysis could be a substantial tropospheric nitrogen oxide source. Recycling of nitrogen oxides in remote oceanic regions with minimal direct nitrogen oxide emissions could increase the formation of tropospheric oxidants and secondary atmospheric aerosols on a global scale.

  10. Nitrogen oxides from burning forest fuels examined by thermogravimetry and evolved gas analysis

    Treesearch

    H.B. Clements; Charles K. McMahon

    1980-01-01

    Abstract. Twelve forest fuels that varied widely in nitrogen content were burned in a thermogravimetric system, and nitrogen oxide production was analyzed by chemiluminescence. The effects of fuel nitrogen concentration, available oxygen, flow rate, and heating rate on nitrogen oxide production were examined.Results show that fuel nitrogen is an...

  11. 40 CFR 52.278 - Oxides of nitrogen control.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Oxides of nitrogen control. 52.278... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.278 Oxides of nitrogen control. (a) The following regulations are disapproved because they relax the control of nitrogen oxides...

  12. 40 CFR 52.278 - Oxides of nitrogen control.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Oxides of nitrogen control. 52.278... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.278 Oxides of nitrogen control. (a) The following regulations are disapproved because they relax the control of nitrogen oxides...

  13. 40 CFR 52.278 - Oxides of nitrogen control.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Oxides of nitrogen control. 52.278... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.278 Oxides of nitrogen control. (a) The following regulations are disapproved because they relax the control of nitrogen oxides...

  14. 40 CFR 52.278 - Oxides of nitrogen control.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Oxides of nitrogen control. 52.278... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.278 Oxides of nitrogen control. (a) The following regulations are disapproved because they relax the control of nitrogen oxides...

  15. Interactions between nitrogen cycling and methane oxidation in the pelagic waters of the Gulf of Mexico.

    NASA Astrophysics Data System (ADS)

    Joye, S. B.; Weber, S.; Battles, J.; Montoya, J. P.

    2014-12-01

    Methane is an important greenhouse gas that plays a critical role in climate variation. Although a variety of marine methane sources and sinks have been identified, key aspects of the fate of methane in the ocean remain poorly constrained. At cold seeps in the Gulf of Mexico and elsewhere, methane is introduced into the overlying water column via fluid escape from the seabed. We quantified the fate of methane in the water column overlying seafloor cold seeps, in a brine basin, and at several control sites. Our goals were to determine the factors that regulated methane consumption and assimilation and to explore how these controlling factors varied among and between sites. In particular, we examined the impact of nitrogen availability on methane oxidation and studied the ability of methane oxidizing bacteria to fix molecular nitrogen. Methane oxidation rates were highest in the methane rich bottom waters of natural hydrocabron seeps. At these sites, inorganic nitrogen addition stimulated methane oxidation in laboratory experiments. In vitro shipboard experiments revealed that rates of methane oxidation and nitrogen fixation were correlated strongly, suggesting that nitrogen fixation may have been mediated by methanotrophic bacteria. The highest rates of methane oxidation and nitrogen fixation were observed in the deepwater above at natural hydrocarbon seeps. Rates of methane oxidation were substantial along the chemocline of a brine basin but in these ammonium-rich brines, addition of inorganic nitrogen had little impact on methane oxidation suggesting that methanotrophy in these waters were not nitrogen limited. Control sites exhibited the lowest methane concentrations and methane oxidation rates but even these waters exhibited substantial potential for methane oxidation when methane and inorganic nitrogen concentrations were increased. Together, these data suggest that the availability of inorganic nitrogen plays a critical role in regulating methane oxidation in pelagic ocean waters. Some methanotrophs may obtain a competitive advantage in nitrogen-limited oceanic environments by fixing molecular nitrogen. The importance of such "methano-diazotrophy" on a global scale warrants further investigation.

  16. 40 CFR 86.1323-2007 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 19 2011-07-01 2011-07-01 false Oxides of nitrogen analyzer... Exhaust Test Procedures § 86.1323-2007 Oxides of nitrogen analyzer calibration. This section describes the initial and periodic calibration of the chemiluminescent oxides of nitrogen analyzer. (a) Prior to...

  17. 40 CFR 86.1323-2007 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Oxides of nitrogen analyzer... Exhaust Test Procedures § 86.1323-2007 Oxides of nitrogen analyzer calibration. This section describes the initial and periodic calibration of the chemiluminescent oxides of nitrogen analyzer. (a) Prior to...

  18. 40 CFR 86.1323-2007 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 20 2013-07-01 2013-07-01 false Oxides of nitrogen analyzer... Exhaust Test Procedures § 86.1323-2007 Oxides of nitrogen analyzer calibration. This section describes the initial and periodic calibration of the chemiluminescent oxides of nitrogen analyzer. (a) Prior to...

  19. 40 CFR 86.1323-2007 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 20 2012-07-01 2012-07-01 false Oxides of nitrogen analyzer... Exhaust Test Procedures § 86.1323-2007 Oxides of nitrogen analyzer calibration. This section describes the initial and periodic calibration of the chemiluminescent oxides of nitrogen analyzer. (a) Prior to...

  20. 40 CFR 89.112 - Oxides of nitrogen, carbon monoxide, hydrocarbon, and particulate matter exhaust emission standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Oxides of nitrogen, carbon monoxide....112 Oxides of nitrogen, carbon monoxide, hydrocarbon, and particulate matter exhaust emission... emissions of oxides of nitrogen, carbon monoxide, hydrocarbon, and nonmethane hydrocarbon are measured using...

  1. 40 CFR 89.112 - Oxides of nitrogen, carbon monoxide, hydrocarbon, and particulate matter exhaust emission standards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Oxides of nitrogen, carbon monoxide....112 Oxides of nitrogen, carbon monoxide, hydrocarbon, and particulate matter exhaust emission... emissions of oxides of nitrogen, carbon monoxide, hydrocarbon, and nonmethane hydrocarbon are measured using...

  2. 40 CFR 89.112 - Oxides of nitrogen, carbon monoxide, hydrocarbon, and particulate matter exhaust emission standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Oxides of nitrogen, carbon monoxide....112 Oxides of nitrogen, carbon monoxide, hydrocarbon, and particulate matter exhaust emission... emissions of oxides of nitrogen, carbon monoxide, hydrocarbon, and nonmethane hydrocarbon are measured using...

  3. 40 CFR 86.332-79 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Oxides of nitrogen analyzer... Procedures § 86.332-79 Oxides of nitrogen analyzer calibration. (a) At least monthly during testing, perform.... (2) Zero the oxides of nitrogen analyzer. (3) Connect the outlet of the NOX generator (see Figure D79...

  4. 40 CFR 92.121 - Oxides of nitrogen analyzer calibration and check.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Oxides of nitrogen analyzer... Procedures § 92.121 Oxides of nitrogen analyzer calibration and check. (a) Quench checks; NO X analyzer. (1... performed in step in paragraph (a)(3)(i) this section. (b) Oxides of nitrogen analyzer calibration. (1...

  5. 40 CFR 92.121 - Oxides of nitrogen analyzer calibration and check.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Oxides of nitrogen analyzer calibration... Procedures § 92.121 Oxides of nitrogen analyzer calibration and check. (a) Quench checks; NO X analyzer. (1... performed in step in paragraph (a)(3)(i) this section. (b) Oxides of nitrogen analyzer calibration. (1...

  6. 40 CFR 86.332-79 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Oxides of nitrogen analyzer... Procedures § 86.332-79 Oxides of nitrogen analyzer calibration. (a) At least monthly during testing, perform.... (2) Zero the oxides of nitrogen analyzer. (3) Connect the outlet of the NOX generator (see Figure D79...

  7. 40 CFR 92.121 - Oxides of nitrogen analyzer calibration and check.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Oxides of nitrogen analyzer... Procedures § 92.121 Oxides of nitrogen analyzer calibration and check. (a) Quench checks; NO X analyzer. (1... performed in step in paragraph (a)(3)(i) this section. (b) Oxides of nitrogen analyzer calibration. (1...

  8. 40 CFR 92.121 - Oxides of nitrogen analyzer calibration and check.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Oxides of nitrogen analyzer... Procedures § 92.121 Oxides of nitrogen analyzer calibration and check. (a) Quench checks; NO X analyzer. (1... performed in step in paragraph (a)(3)(i) this section. (b) Oxides of nitrogen analyzer calibration. (1...

  9. Regulated and unregulated emissions from modern 2010 emissions-compliant heavy-duty on-highway diesel engines.

    PubMed

    Khalek, Imad A; Blanks, Matthew G; Merritt, Patrick M; Zielinska, Barbara

    2015-08-01

    The U.S. Environmental Protection Agency (EPA) established strict regulations for highway diesel engine exhaust emissions of particulate matter (PM) and nitrogen oxides (NOx) to aid in meeting the National Ambient Air Quality Standards. The emission standards were phased in with stringent standards for 2007 model year (MY) heavy-duty engines (HDEs), and even more stringent NOX standards for 2010 and later model years. The Health Effects Institute, in cooperation with the Coordinating Research Council, funded by government and the private sector, designed and conducted a research program, the Advanced Collaborative Emission Study (ACES), with multiple objectives, including detailed characterization of the emissions from both 2007- and 2010-compliant engines. The results from emission testing of 2007-compliant engines have already been reported in a previous publication. This paper reports the emissions testing results for three heavy-duty 2010-compliant engines intended for on-highway use. These engines were equipped with an exhaust diesel oxidation catalyst (DOC), high-efficiency catalyzed diesel particle filter (DPF), urea-based selective catalytic reduction catalyst (SCR), and ammonia slip catalyst (AMOX), and were fueled with ultra-low-sulfur diesel fuel (~6.5 ppm sulfur). Average regulated and unregulated emissions of more than 780 chemical species were characterized in engine exhaust under transient engine operation using the Federal Test Procedure cycle and a 16-hr duty cycle representing a wide dynamic range of real-world engine operation. The 2010 engines' regulated emissions of PM, NOX, nonmethane hydrocarbons, and carbon monoxide were all well below the EPA 2010 emission standards. Moreover, the unregulated emissions of polycyclic aromatic hydrocarbons (PAHs), nitroPAHs, hopanes and steranes, alcohols and organic acids, alkanes, carbonyls, dioxins and furans, inorganic ions, metals and elements, elemental carbon, and particle number were substantially (90 to >99%) lower than pre-2007-technology engine emissions, and also substantially (46 to >99%) lower than the 2007-technology engine emissions characterized in the previous study.

  10. Biofilter for removal of nitrogen oxides from contaminated gases under aerobic conditions

    DOEpatents

    Apel, William A.

    1998-01-01

    A biofilter for reducing concentrations of gaseous nitrogen oxides in a polluted gas comprises a porous organic filter bed medium disposed in a housing, the filter bed medium including a mixed culture of naturally occurring denitrifying bacteria for converting the nitrogen oxides to nitrogen gas, carbon dioxide, and water. A method of reducing concentrations of nitrogen oxides in polluted gas comprises conducting the polluted gas through the biofilter so that the denitrifying bacteria can degrade the nitrogen oxides. A preferred filter medium is wood compost, however composts of other organic materials are functional. Regulation of pH, moisture content, exogenous carbon sources, and temperature are described.

  11. 40 CFR 52.770 - Identification of plan.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 11/30/2004, 69 FR 69531. Article 10. Nitrogen Oxides Rules 10-1 Nitrogen Oxides Control in Clark and Floyd Counties 6/12/1996 6/3/1997, 62 FR 30253. 10-3 Nitrogen Oxide Reduction Program for Specific Source Categories 02/25/2007 11/29/2010, 75 FR 72956 Sec. 1. 10-4 Nitrogen Oxides Budget Trading Program...

  12. ROLE OF NITROGEN OXIDES IN NONURBAN OZONE FORMATION IN THE PLANETARY BOUNDARY LAYER OVER N (NORTH) AMERICA, W (WESTERN) EUROPE AND ADJACENT AREAS OF OCEAN

    EPA Science Inventory

    The status of knowledge on photochemical ozone formation and the effects of nitrogen oxides and peroxyacyl nitrates on such formation has been evaluated. The literature is reviewed on nonurban ozone and nitrogen oxide concentration distributions, ozone lifetimes, nitrogen oxide l...

  13. 40 CFR 60.55a - Standard for nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for nitrogen oxides. 60.55a... § 60.55a Standard for nitrogen oxides. On and after the date on which the initial compliance test is... gases that contain nitrogen oxides in excess of 180 parts per million by volume, corrected to 7 percent...

  14. 40 CFR Table 2 to Subpart Fff of... - Nitrogen Oxides Requirements for Affected Facilities

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 8 2011-07-01 2011-07-01 false Nitrogen Oxides Requirements for... Before September 20, 1994 Pt. 62, Subpt. FFF, Table 2 Table 2 to Subpart FFF of Part 62—Nitrogen Oxides Requirements for Affected Facilities Municipal waste combustor technology Nitrogen oxides emission limit (parts...

  15. 40 CFR Table 1 to Subpart Cb of... - Nitrogen Oxides Guidelines for Designated Facilities

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Nitrogen Oxides Guidelines for... September 20, 1994 Pt. 60, Subpt. Cb, Table 1 Table 1 to Subpart Cb of part 60—Nitrogen Oxides Guidelines for Designated Facilities Municipal waste combustor technology Before April 28, 2009,nitrogen oxides...

  16. 40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified in...

  17. 40 CFR Table 2 to Subpart Fff of... - Nitrogen Oxides Requirements for Affected Facilities

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 9 2014-07-01 2014-07-01 false Nitrogen Oxides Requirements for... Before September 20, 1994 Pt. 62, Subpt. FFF, Table 2 Table 2 to Subpart FFF of Part 62—Nitrogen Oxides Requirements for Affected Facilities Municipal waste combustor technology Nitrogen oxides emission limit (parts...

  18. 40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified in...

  19. 40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified in...

  20. 40 CFR 60.55a - Standard for nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for nitrogen oxides. 60.55a... § 60.55a Standard for nitrogen oxides. On and after the date on which the initial compliance test is... gases that contain nitrogen oxides in excess of 180 parts per million by volume, corrected to 7 percent...

  1. 40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified in...

  2. 40 CFR Table 2 to Subpart Fff of... - Nitrogen Oxides Requirements for Affected Facilities

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 9 2012-07-01 2012-07-01 false Nitrogen Oxides Requirements for... Before September 20, 1994 Pt. 62, Subpt. FFF, Table 2 Table 2 to Subpart FFF of Part 62—Nitrogen Oxides Requirements for Affected Facilities Municipal waste combustor technology Nitrogen oxides emission limit (parts...

  3. 40 CFR Table 2 to Subpart Fff of... - Nitrogen Oxides Requirements for Affected Facilities

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 9 2013-07-01 2013-07-01 false Nitrogen Oxides Requirements for... Before September 20, 1994 Pt. 62, Subpt. FFF, Table 2 Table 2 to Subpart FFF of Part 62—Nitrogen Oxides Requirements for Affected Facilities Municipal waste combustor technology Nitrogen oxides emission limit (parts...

  4. 40 CFR 60.55a - Standard for nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for nitrogen oxides. 60.55a... § 60.55a Standard for nitrogen oxides. On and after the date on which the initial compliance test is... gases that contain nitrogen oxides in excess of 180 parts per million by volume, corrected to 7 percent...

  5. 40 CFR Table 1 to Subpart Cb of... - Nitrogen Oxides Guidelines for Designated Facilities

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Nitrogen Oxides Guidelines for... September 20, 1994 Pt. 60, Subpt. Cb, Table 1 Table 1 to Subpart Cb of Part 60—Nitrogen Oxides Guidelines for Designated Facilities Municipal waste combustor technology Before April 28, 2009,nitrogen oxides...

  6. 40 CFR 60.55a - Standard for nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for nitrogen oxides. 60.55a... § 60.55a Standard for nitrogen oxides. On and after the date on which the initial compliance test is... gases that contain nitrogen oxides in excess of 180 parts per million by volume, corrected to 7 percent...

  7. Denitrification of combustion gases. [Patent application

    DOEpatents

    Yang, R.T.

    1980-10-09

    A method for treating waste combustion gas to remove the nitrogen oxygen gases therefrom is disclosed wherein the waste gas is first contacted with calcium oxide which absorbs and chemically reacts with the nitrogen oxide gases therein at a temperature from about 100/sup 0/ to 430/sup 0/C. The thus reacted calcium oxide (now calcium nitrate) is then heated at a temperature range between about 430/sup 0/ and 900/sup 0/C, resulting in regeneration of the calcium oxide and production of the decomposition gas composed of nitrogen and nitrogen oxide gas. The decomposition gases can be recycled to the calcium oxide contacting step to minimize the amount of nitrogen oxide gases in the final product gas.

  8. 40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 2 2011-07-01 2011-07-01 false National primary and secondary ambient air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). 50.11 Section... quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). (a) The level of the...

  9. 40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false National primary and secondary ambient air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). 50.11 Section... quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). (a) The level of the...

  10. 40 CFR 60.72 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for nitrogen oxides. 60.72... Plants § 60.72 Standard for nitrogen oxides. (a) On and after the date on which the performance test...) Contain nitrogen oxides, expressed as NO2, in excess of 1.5 kg per metric ton of acid produced (3.0 lb per...

  11. 40 CFR 60.72 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for nitrogen oxides. 60.72... Plants § 60.72 Standard for nitrogen oxides. (a) On and after the date on which the performance test...) Contain nitrogen oxides, expressed as NO2, in excess of 1.5 kg per metric ton of acid produced (3.0 lb per...

  12. 40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 60.33b Section 60.33b Protection of Environment..., acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals... oxygen. (d) For approval, a State plan shall include emission limits for nitrogen oxides at least as...

  13. 40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 60.33b Section 60.33b Protection of Environment..., acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals... oxygen. (d) For approval, a State plan shall include emission limits for nitrogen oxides at least as...

  14. 40 CFR 60.72 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for nitrogen oxides. 60.72... Plants § 60.72 Standard for nitrogen oxides. (a) On and after the date on which the performance test...) Contain nitrogen oxides, expressed as NO2, in excess of 1.5 kg per metric ton of acid produced (3.0 lb per...

  15. 40 CFR 60.72 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for nitrogen oxides. 60.72... Plants § 60.72 Standard for nitrogen oxides. (a) On and after the date on which the performance test...) Contain nitrogen oxides, expressed as NO2, in excess of 1.5 kg per metric ton of acid produced (3.0 lb per...

  16. 40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 60.33b Section 60.33b Protection of Environment..., acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals... oxygen. (d) For approval, a State plan shall include emission limits for nitrogen oxides at least as...

  17. 40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 60.33b Section 60.33b Protection of Environment..., acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals... oxygen. (d) For approval, a State plan shall include emission limits for nitrogen oxides at least as...

  18. A Spatial Panel Data Analysis of Economic Growth, Urbanization, and NOx Emissions in China

    PubMed Central

    Ge, Xiangyu; Zhou, Yanli; Liu, Songlin

    2018-01-01

    Is nitrogen oxides emissions spatially correlated in a Chinese context? What is the relationship between nitrogen oxides emission levels and fast-growing economy/urbanization? More importantly, what environmental preservation and economic developing policies should China’s central and local governments take to mitigate the overall nitrogen oxides emissions and prevent severe air pollution at the provincial level in specific locations and their neighboring areas? The present study aims to tackle these issues. This is the first research that simultaneously studies the nexus between nitrogen oxides emissions and economic development/urbanization, with the application of a spatial panel data technique. Our empirical findings suggest that spatial dependence of nitrogen oxides emissions distribution exists at the provincial level. Through the investigation of the existence of an environmental Kuznets curve (EKC) embedded within the Stochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) framework, we conclude something interesting: an inverse N-shaped EKC describes both the income-nitrogen oxides nexus and the urbanization-nitrogen oxides nexus. Some well-directed policy advice is provided to reduce nitrogen oxides in the future. Moreover, these results contribute to the literature on development and pollution. PMID:29641500

  19. A Spatial Panel Data Analysis of Economic Growth, Urbanization, and NOx Emissions in China.

    PubMed

    Ge, Xiangyu; Zhou, Zhimin; Zhou, Yanli; Ye, Xinyue; Liu, Songlin

    2018-04-11

    Abstract : Is nitrogen oxides emissions spatially correlated in a Chinese context? What is the relationship between nitrogen oxides emission levels and fast-growing economy/urbanization? More importantly, what environmental preservation and economic developing policies should China's central and local governments take to mitigate the overall nitrogen oxides emissions and prevent severe air pollution at the provincial level in specific locations and their neighboring areas? The present study aims to tackle these issues. This is the first research that simultaneously studies the nexus between nitrogen oxides emissions and economic development/urbanization, with the application of a spatial panel data technique. Our empirical findings suggest that spatial dependence of nitrogen oxides emissions distribution exists at the provincial level. Through the investigation of the existence of an environmental Kuznets curve (EKC) embedded within the Stochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) framework, we conclude something interesting: an inverse N-shaped EKC describes both the income-nitrogen oxides nexus and the urbanization-nitrogen oxides nexus. Some well-directed policy advice is provided to reduce nitrogen oxides in the future. Moreover, these results contribute to the literature on development and pollution.

  20. Air Quality Criteria for Oxides of Nitrogen (Final Report, 1993)

    EPA Science Inventory

    This criteria document focuses on a review and assessment of the effects on human health and welfare of the nitrogen oxides, nitric oxide (NO) and nitrogen dioxide (NO2), and the related compounds, nitrites, nitrates, nitrogenous acids, and nitrosamines. Although the emphasis is ...

  1. Biofilter for removal of nitrogen oxides from contaminated gases under aerobic conditions

    DOEpatents

    Apel, W.A.

    1998-08-18

    A biofilter is described for reducing concentrations of gaseous nitrogen oxides in a polluted gas comprises a porous organic filter bed medium disposed in a housing, the filter bed medium including a mixed culture of naturally occurring denitrifying bacteria for converting the nitrogen oxides to nitrogen gas, carbon dioxide, and water. A method is described of reducing concentrations of nitrogen oxides in polluted gas comprises conducting the polluted gas through the biofilter so that the denitrifying bacteria can degrade the nitrogen oxides. A preferred filter medium is wood compost, however composts of other organic materials are functional. Regulation of pH, moisture content, exogenous carbon sources, and temperature are described. 6 figs.

  2. Explosive Ordnance Disposal Proficiency Range and Multi-Purpose Contingency Training Area

    DTIC Science & Technology

    2007-04-01

    1,3,5-trimethylene-2,4,6-trinitramine (RDX), cyclo-1,3,5,7- tetramethylene-2,4,6,8-tetra-nitramine [HMX], tetryl, and picric acid ; inorganic compounds...nitrogen oxides, which cause acid rain. Ir. addition, nitrogen oxide emissions contribute to the problem of global warming and also r;ombine with...of sUlfur oxide and nitrogen oxides, which cause acid ram. Ji:, addition, nitrogen oxide emis~ions contribute to the probl!llll of global warming

  3. 40 CFR Table 2 to Subpart Cb of... - Nitrogen Oxides Limits for Existing Designated Facilities Included in an Emissions Averaging Plan...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Nitrogen Oxides Limits for Existing.... 60, Subpt. Cb, Table 2 Table 2 to Subpart Cb of Part 60—Nitrogen Oxides Limits for Existing... by volume) b On and after April 28, 2009, nitrogen oxides emission limit (parts permillion by volume...

  4. 40 CFR Table 2 to Subpart Cb of... - Nitrogen Oxides Limits for Existing Designated Facilities Included in an Emissions Averaging Plan...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Nitrogen Oxides Limits for Existing.... 60, Subpt. Cb, Table 2 Table 2 to Subpart Cb of Part 60—Nitrogen Oxides Limits for Existing... by volume) b On and after April 28, 2009, nitrogen oxides emission limit (parts permillion by volume...

  5. 40 CFR Table 2 to Subpart Cb of... - Nitrogen Oxides Limits for Existing Designated Facilities Included in an Emissions Averaging Plan...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Nitrogen Oxides Limits for Existing.... 60, Subpt. Cb, Table 2 Table 2 to Subpart Cb of Part 60—Nitrogen Oxides Limits for Existing... by volume) b On and after April 28, 2009, nitrogen oxides emission limit (parts permillion by volume...

  6. 40 CFR Table 2 to Subpart Cb of... - Nitrogen Oxides Limits for Existing Designated Facilities Included in an Emissions Averaging Plan...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Nitrogen Oxides Limits for Existing.... 60, Subpt. Cb, Table 2 Table 2 to Subpart Cb of Part 60—Nitrogen Oxides Limits for Existing... by volume) b On and after April 28, 2009, nitrogen oxides emission limit (parts permillion by volume...

  7. 40 CFR Table 2 to Subpart Cb of... - Nitrogen Oxides Limits for Existing Designated Facilities Included in an Emissions Averaging Plan...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Nitrogen Oxides Limits for Existing.... 60, Subpt. Cb, Table 2 Table 2 to Subpart Cb of Part 60—Nitrogen Oxides Limits for Existing... by volume) b On and after April 28, 2009, nitrogen oxides emission limit (parts permillion by volume...

  8. 40 CFR Appendix B to Part 76 - Procedures and Methods for Estimating Costs of Nitrogen Oxides Controls Applied to Group 1, Boilers

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Costs of Nitrogen Oxides Controls Applied to Group 1, Boilers B Appendix B to Part 76 Protection of... of Nitrogen Oxides Controls Applied to Group 1, Boilers 1. Purpose and Applicability This technical...; and which is comparable to the costs of nitrogen oxides controls set pursuant to subsection (b)(1) (of...

  9. 40 CFR Appendix B to Part 76 - Procedures and Methods for Estimating Costs of Nitrogen Oxides Controls Applied to Group 1, Boilers

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Costs of Nitrogen Oxides Controls Applied to Group 1, Boilers B Appendix B to Part 76 Protection of... of Nitrogen Oxides Controls Applied to Group 1, Boilers 1. Purpose and Applicability This technical...; and which is comparable to the costs of nitrogen oxides controls set pursuant to subsection (b)(1) (of...

  10. 40 CFR Appendix B to Part 76 - Procedures and Methods for Estimating Costs of Nitrogen Oxides Controls Applied to Group 1, Boilers

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Costs of Nitrogen Oxides Controls Applied to Group 1, Boilers B Appendix B to Part 76 Protection of... of Nitrogen Oxides Controls Applied to Group 1, Boilers 1. Purpose and Applicability This technical...; and which is comparable to the costs of nitrogen oxides controls set pursuant to subsection (b)(1) (of...

  11. 40 CFR Appendix B to Part 76 - Procedures and Methods for Estimating Costs of Nitrogen Oxides Controls Applied to Group 1, Boilers

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Costs of Nitrogen Oxides Controls Applied to Group 1, Boilers B Appendix B to Part 76 Protection of... of Nitrogen Oxides Controls Applied to Group 1, Boilers 1. Purpose and Applicability This technical...; and which is comparable to the costs of nitrogen oxides controls set pursuant to subsection (b)(1) (of...

  12. 40 CFR Appendix B to Part 76 - Procedures and Methods for Estimating Costs of Nitrogen Oxides Controls Applied to Group 1, Boilers

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Costs of Nitrogen Oxides Controls Applied to Group 1, Boilers B Appendix B to Part 76 Protection of... of Nitrogen Oxides Controls Applied to Group 1, Boilers 1. Purpose and Applicability This technical...; and which is comparable to the costs of nitrogen oxides controls set pursuant to subsection (b)(1) (of...

  13. Application of a Chemiluminescence Detector for the Measurement of Total Oxides of Nitrogen and Ammonia in the Atmosphere

    NASA Technical Reports Server (NTRS)

    Hodgeson, J. A.; Bell, J. P.; Rehme, K. A.; Krost, K. J.; Stevens, R. K.

    1971-01-01

    By means of the thermal conversion of nitrogen dioxide to the nitric oxide, the chemiluminescent nitric oxide monitor, based on the nitric oxide plus ozone reaction, may be used for monitoring nitrogen dioxide plus nitric oxide (NO(x)). Under conditions previously described, ammonia is also converted to nitric oxide and therefore interferes. A metal surface, gold wool or stainless steel, operated at two different temperatures has been used to convert only nitrogen dioxide or nitrogen dioxide plus ammonia. Quantitative conversion of nitrogen dioxide to nitric oxide has been obtained at temperatures as low as 200 C. Conversion of ammonia is effected at temperatures of 300 C or higher. By the addition of a converter the basic nitric oxide monitor may be used for measuring NO(x) or NO(x) plus ammonia. As an alternate mode, for a fixed high temperature, a specific scrubber is described for removing NH3 without affecting NO2 concentrations.

  14. Nitrogen-doped graphene: effect of graphite oxide precursors and nitrogen content on the electrochemical sensing properties.

    PubMed

    Megawati, Monica; Chua, Chun Kiang; Sofer, Zdenek; Klímová, Kateřina; Pumera, Martin

    2017-06-21

    Graphene, produced via chemical methods, has been widely applied for electrochemical sensing due to its structural and electrochemical properties as well as its ease of production in large quantity. While nitrogen-doped graphenes are widely studied materials, the literature showing an effect of graphene oxide preparation methods on nitrogen quantity and chemical states as well as on defects and, in turn, on electrochemical sensing is non-existent. In this study, the properties of nitrogen-doped graphene materials, prepared via hydrothermal synthesis using graphite oxide produced by various classical methods using permanganate or chlorate oxidants Staudenmaier, Hummers, Hofmann and Brodie oxidation methods, were studied; the resulting nitrogen-doped graphene oxides were labeled as ST-GO, HU-GO, HO-GO and BR-GO, respectively. The electrochemical oxidation of biomolecules, such as ascorbic acid, uric acid, dopamine, nicotinamide adenine nucleotide and DNA free bases, was carried out using cyclic voltammetry and differential pulse voltammetry techniques. The nitrogen content in doped graphene oxides increased in the order ST-GO < BR-GO < HO-GO < HU-GO. In the same way, the pyridinic form of nitrogen increased and the electrocatalytic effect of N-doped graphene followed this trend, as shown in the cyclic voltammograms. This is a very important finding that provides insight into the electrocatalytic effect of N-doped graphene. The nitrogen-doped graphene materials exhibited improved sensitivity over bare glassy carbon for ascorbic acid, uric acid and dopamine detection. These studies will enhance our understanding of the effects of graphite oxide precursors on the electrochemical sensing properties of nitrogen-doped graphene materials.

  15. Sustainable synthesis of aldehydes, ketones or acids from neat alcohols using nitrogen dioxide gas, and related reactions.

    PubMed

    Naimi-Jamal, M Reza; Hamzeali, Hamideh; Mokhtari, Javad; Boy, Jürgen; Kaupp, Gerd

    2009-01-01

    Benzylic alcohols are quantitatively oxidized by gaseous nitrogen dioxide to give pure aromatic aldehydes. The reaction gas mixtures are transformed to nitric acid, which renders the processes free of waste. The exothermic gas-liquid or gas-solid reactions profit from the solubility of nitrogen dioxide in the neat benzylic alcohols. The acid formed impedes further oxidation of the benzaldehydes. The neat isolated benzaldehydes and nitrogen dioxide quantitatively give the benzoic acids. Solid long-chain primary alcohols are directly and quantitatively oxidized with nitrogen dioxide gas to give the fatty acids in the solid state. The oxidations with ubiquitous nitrogen dioxide are extended to solid heterocyclic thioamides, which gives disulfides, and to diphenylamine, which gives tetraphenylhydrazine. These sustainable (green) specific oxidation procedures produce no dangerous residues from the oxidizing agent or from auxiliaries.

  16. 40 CFR 52.34 - Action on petitions submitted under section 126 relating to emissions of nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... section 126 relating to emissions of nitrogen oxides. 52.34 Section 52.34 Protection of Environment... of nitrogen oxides. (a) Definitions. For purposes of this section, the following definitions apply... of nitrogen. (6) OTAG means the Ozone Transport Assessment Group (active 1995-1997), a national work...

  17. 40 CFR 52.34 - Action on petitions submitted under section 126 relating to emissions of nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... section 126 relating to emissions of nitrogen oxides. 52.34 Section 52.34 Protection of Environment... of nitrogen oxides. (a) Definitions. For purposes of this section, the following definitions apply... of nitrogen. (6) OTAG means the Ozone Transport Assessment Group (active 1995-1997), a national work...

  18. 40 CFR 52.34 - Action on petitions submitted under section 126 relating to emissions of nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... section 126 relating to emissions of nitrogen oxides. 52.34 Section 52.34 Protection of Environment... of nitrogen oxides. (a) Definitions. For purposes of this section, the following definitions apply... of nitrogen. (6) OTAG means the Ozone Transport Assessment Group (active 1995-1997), a national work...

  19. 40 CFR 86.523-78 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... analyzer to optimize performance. (2) Zero the oxides of nitrogen analyzer with zero grade air or zero... samples. Proceed as follows: (1) Adjust analyzer to optimize performance. (2) Zero the oxides of nitrogen analyzer with zero grade air or zero grade nitrogen. (3) Calibrate on each normally used operating range...

  20. Simultaneous removal of nitrogen oxides and sulfur oxides from combustion gases

    DOEpatents

    Clay, David T.; Lynn, Scott

    1976-10-19

    A process for the simultaneous removal of sulfur oxides and nitrogen oxides from power plant stack gases comprising contacting the stack gases with a supported iron oxide catalyst/absorbent in the presence of sufficient reducing agent selected from the group consisting of carbon monoxide, hydrogen, and mixtures thereof, to provide a net reducing atmosphere in the SO.sub.x /NO.sub.x removal zone. The sulfur oxides are removed by absorption substantially as iron sulfide, and nitrogen oxides are removed by catalytic reduction to nitrogen and ammonia. The spent iron oxide catalyst/absorbent is regenerated by oxidation and is recycled to the contacting zone. Sulfur dioxide is also produced during regeneration and can be utilized in the production of sulfuric acid and/or sulfur.

  1. Nitrogen Dioxide's Impact on Indoor Air Quality

    EPA Pesticide Factsheets

    The two most prevalent oxides of nitrogen are nitrogen dioxide (NO2) and nitric oxide (NO). Both are toxic gases with NO2 being a highly reactive oxidant and corrosive. The primary sources indoors are combustion processes.

  2. Oxidized Nitrogen in Precipitation, Throughfall, and Streamfall from a Forested Watershed in Oklahoma

    USGS Publications Warehouse

    Lawrence, Stephen J.; Wigington, Parker J.

    1987-01-01

    Oxidized nitrogen (nitrite plus nitrate N) concentrations were measured from bulk precipitation, bulk throughfall, and screamflow in a 7. 86 hectare forested watershed in southeastern Oklahoma during the wet season from March through June 1983. Oxidized nitrogen inputs comparable to results of other studies were recorded during the 19 rainstorms sampled. Oxidized nitrogen concentrations appeared to increase after rainfall interacted with the pine and hardwood canopies and were inversely related to both rainfall and throughfall depth. Oxidized N concentrations in streamflow were greatest during the rising limb of storm flow with subsequent decreases during the falling limb of storm hydrographs and lowest during base flow. The oxidized N inputs from bulk precipitation were considerably greater than outputs from streamflow resulting in a net retention of oxidized nitrogen within the watershed during the study period.

  3. Removal of sulfur and nitrogen containing pollutants from discharge gases

    DOEpatents

    Joubert, James I.

    1986-01-01

    Oxides of sulfur and of nitrogen are removed from waste gases by reaction with an unsupported copper oxide powder to form copper sulfate. The resulting copper sulfate is dissolved in water to effect separation from insoluble mineral ash and dried to form solid copper sulfate pentahydrate. This solid sulfate is thermally decomposed to finely divided copper oxide powder with high specific surface area. The copper oxide powder is recycled into contact with the waste gases requiring cleanup. A reducing gas can be introduced to convert the oxide of nitrogen pollutants to nitrogen.

  4. Effect of fuel nitrogen and hydrogen content on emissions in hydrocarbon combustion

    NASA Technical Reports Server (NTRS)

    Bittker, D. A.; Wolfbrandt, G.

    1981-01-01

    How the emissions of nitrogen oxides and carbon monoxide are affected by: (1) the decreased hydrogen content and (2) the increased organic nitrogen content of coal derived fuels is investigated. Previous CRT experimental work in a two stage flame tube has shown the effectiveness of rich lean two stage combustion in reducing fuel nitrogen conversion to nitrogen oxides. Previous theoretical work gave preliminary indications that emissions trends from the flame tube experiment could be predicted by a two stage, well stirred reactor combustor model using a detailed chemical mechanism for propane oxidation and nitrogen oxide formation. Additional computations are reported and comparisons with experimental results for two additional fuels and a wide range of operating conditions are given. Fuels used in the modeling are pure propane, a propane toluene mixture and pure toluene. These give hydrogen contents 18, 11 and 9 percent by weight, respectively. Fuel bound nitrogen contents of 0.5 and 1.0 percent were used. Results are presented for oxides of nitrogen and also carbon monoxide concentrations as a function of primary equivalence ratio, hydrogen content and fuel bound nitrogen content.

  5. 40 CFR 52.1876 - Control strategy: Nitrogen dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...: Nitrogen dioxide. (a) The condition to EPA's approval of the oxides of nitrogen State Implementation Plan... change to the flow control date in the oxides of nitrogen budget trading SIP. (b) [Reserved] [69 FR 13234...

  6. The effect of emission from coal combustion in nonindustrial sources on deposition of sulfur and oxidized nitrogen in Poland.

    PubMed

    Kryza, Maciej; Werner, Małgorzata; Błaś, Marek; Dore, Anthony J; Sobik, Mieczysław

    2010-07-01

    Poland has one of the largest sulfur and nitrogen emissions in Europe. This is mainly because coal is a main fuel in industrial and nonindustrial combustion. The aim of this paper is to assess the amount of sulfur and nitrogen deposited from SNAP sector 02 (nonindustrial sources) coal combustion. To assess this issue, the Fine Resolution Atmospheric Multipollutant Exchange (FRAME) model was used. The results suggest that industrial combustion has the largest impact on deposition of oxidized sulfur, whereas the oxidized nitrogen national deposition budget is dominated by transboundary transport. The total mass of pollutants deposited in Poland, originating from nonindustrial coal combustion, is 45 Gg of sulfur and 2.5 Gg of nitrogen, which is over 18% of oxidized sulfur and nearly 2% of oxidized nitrogen deposited. SNAP 02 is responsible for up to 80% of dry-deposited sulfur and 11% of nitrogen. The contribution to wet deposition is largest in central Poland in the case of sulfur and in some areas can exceed 11%. For oxidized nitrogen, nonindustrial emissions contribute less than 1% over the whole area of Poland. The switch from coal to gas fuel in this sector will result in benefits in sulfur and nitrogen deposition reduction.

  7. Plasma-chemical processes accompanying discharge in air excited by a microwave beam

    NASA Astrophysics Data System (ADS)

    Askar'ian, G. A.; Batanov, G. M.; Gritsinin, S. I.; Kossyi, I. A.; Kostinskii, A. Iu.

    1990-11-01

    Experimental results are presented on plasma-chemical processes of nitrogen oxidation and ozone production accompanying microwave discharge in dry air and in nitrogen-oxygen mixtures. The degree of nitrogen oxidation and the energy expenditure toward the formation of oxides as a function of discharge conditions are established. The experimental results can be explained by assuming oxidation reactions of electron-excited metastable nitrogen molecules by oxygen atoms. Low ozone concentrations in the discharge indicate a significant energy input into the gas.

  8. Electrochemical wastewater treatment: influence of the type of carbon and of nitrogen on the organic load removal.

    PubMed

    Fernandes, Annabel; Coelho, João; Ciríaco, Lurdes; Pacheco, Maria José; Lopes, Ana

    2016-12-01

    Boron-doped diamond (BDD) and Ti/Pt/PbO 2 anodes were utilized to perform the electrodegradation of synthetic samples containing humic acid in the presence of different organic and inorganic carbon-containing and nitrogen-containing compounds. The influence of the chloride ion in the degradation process of the different synthetic samples was also assessed. The results showed that the anodic oxidation process can efficiently degrade recalcitrant compounds such as humic acid. The presence of carbonate in solution enhances the nitrogen removal, whereas it hinders the oxidation of the organic compounds. When organic nitrogen is present, it is converted to NH 4 + , which in turn is oxidized to nitrate and to volatile nitrogen compounds. Hydroxyl radicals are more prone to oxidize the organic nitrogen than the ammonium nitrogen. The presence of chloride enhances the organic matter and nitrogen removal rates, BDD being the anode material that yields the highest removals.

  9. 40 CFR 52.675 - Control strategy: Sulfur oxides-Eastern Idaho Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of Sulfur Oxide Emissions from Sulfuric Acid Plants) of the “Rules and Regulations for the Control of... have previously been established for certain existing acid plants in this Air Quality Control Region... apply to existing acid plants with approved or promulgated emission limits that are more stringent than...

  10. 40 CFR 52.675 - Control strategy: Sulfur oxides-Eastern Idaho Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of Sulfur Oxide Emissions from Sulfuric Acid Plants) of the “Rules and Regulations for the Control of... have previously been established for certain existing acid plants in this Air Quality Control Region... apply to existing acid plants with approved or promulgated emission limits that are more stringent than...

  11. 40 CFR 52.675 - Control strategy: Sulfur oxides-Eastern Idaho Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of Sulfur Oxide Emissions from Sulfuric Acid Plants) of the “Rules and Regulations for the Control of... have previously been established for certain existing acid plants in this Air Quality Control Region... apply to existing acid plants with approved or promulgated emission limits that are more stringent than...

  12. 40 CFR 52.675 - Control strategy: Sulfur oxides-Eastern Idaho Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... of Sulfur Oxide Emissions from Sulfuric Acid Plants) of the “Rules and Regulations for the Control of... have previously been established for certain existing acid plants in this Air Quality Control Region... apply to existing acid plants with approved or promulgated emission limits that are more stringent than...

  13. 40 CFR 52.675 - Control strategy: Sulfur oxides-Eastern Idaho Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... of Sulfur Oxide Emissions from Sulfuric Acid Plants) of the “Rules and Regulations for the Control of... have previously been established for certain existing acid plants in this Air Quality Control Region... apply to existing acid plants with approved or promulgated emission limits that are more stringent than...

  14. Effects of Particle Filters and Accelerated Engine Replacement on Heavy-Duty Diesel Vehicle Emissions of Black Carbon, Nitrogen Oxides, and Ultrafine Particles

    NASA Astrophysics Data System (ADS)

    Kirchstetter, T.; Preble, C.; Dallmann, T. R.; DeMartini, S. J.; Tang, N. W.; Kreisberg, N. M.; Hering, S. V.; Harley, R. A.

    2013-12-01

    Diesel particle filters have become widely used in the United States since the introduction in 2007 of a more stringent exhaust particulate matter emission standard for new heavy-duty diesel vehicle engines. California has instituted additional regulations requiring retrofit or replacement of older in-use engines to accelerate emission reductions and air quality improvements. This presentation summarizes pollutant emission changes measured over several field campaigns at the Port of Oakland in the San Francisco Bay Area associated with diesel particulate filter use and accelerated modernization of the heavy-duty truck fleet. Pollutants in the exhaust plumes of hundreds of heavy-duty trucks en route to the Port were measured in 2009, 2010, 2011, and 2013. Ultrafine particle number, black carbon (BC), nitrogen oxides (NOx), and nitrogen dioxide (NO2) concentrations were measured at a frequency ≤ 1 Hz and normalized to measured carbon dioxide concentrations to quantify fuel-based emission factors (grams of pollutant emitted per kilogram of diesel consumed). The size distribution of particles in truck exhaust plumes was also measured at 1 Hz. In the two most recent campaigns, emissions were linked on a truck-by-truck basis to installed emission control equipment via the matching of transcribed license plates to a Port truck database. Accelerated replacement of older engines with newer engines and retrofit of trucks with diesel particle filters reduced fleet-average emissions of BC and NOx. Preliminary results from the two most recent field campaigns indicate that trucks without diesel particle filters emit 4 times more BC than filter-equipped trucks. Diesel particle filters increase emissions of NO2, however, and filter-equipped trucks have NO2/NOx ratios that are 4 to 7 times greater than trucks without filters. Preliminary findings related to particle size distribution indicate that (a) most trucks emitted particles characterized by a single mode of approximately 100 nm in diameter and (b) new trucks originally equipped with diesel particle filters were 5 to 6 times more likely than filter-retrofitted trucks and trucks without filters to emit particles characterized by a single mode in the range of 10 to 30 nm in diameter.

  15. 40 CFR 52.278 - Oxides of nitrogen control.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Oxides of nitrogen control. 52.278 Section 52.278 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.278 Oxides of nitrogen control...

  16. 76 FR 11082 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Oxides of Nitrogen Budget...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-01

    ... Promulgation of Air Quality Implementation Plans; Ohio; Oxides of Nitrogen Budget Trading Program; Technical... concerning 240 allowances under the Nitrogen Oxides Budget Trading Program added to the SIP by EPA rulemaking... EPA approve rule revisions [[Page 11083

  17. Treatment of power utilities exhaust

    DOEpatents

    Koermer, Gerald [Basking Ridge, NJ

    2012-05-15

    Provided is a process for treating nitrogen oxide-containing exhaust produced by a stationary combustion source by the catalytic reduction of nitrogen oxide in the presence of a reductant comprising hydrogen, followed by ammonia selective catalytic reduction to further reduce the nitrogen oxide level in the exhaust.

  18. Microbiological Diversity Demonstrates the Potential which Collaboratively Metabolize Nitrogen Oxides ( NOx) under Smog Environmental Stress

    NASA Astrophysics Data System (ADS)

    Chen, X. Z.; Zhao, X. H.; Chen, X. P.

    2018-03-01

    Recently, smoggy weather has become a daily in large part of China because of rapidly economic growth and accelerative urbanization. Stressed on the smoggy situation and economic growth, the green and environment-friendly technology is necessary to reduce or eliminate the smog and promote the sustainable development of economy. Previous studies had confirmed that nitrogen oxides ( NOx ) is one of crucial factors which forms smog. Microorganisms have the advantages of quickly growth and reproduction and metabolic diversity which can collaboratively Metabolize various NOx. This study will design a kind of bacteria & algae cultivation system which can metabolize collaboratively nitrogen oxides in air and intervene in the local nitrogen cycle. Furthermore, the nitrogen oxides can be transformed into nitrogen gas or assembled in protein in microorganism cell by regulating the microorganism types and quantities and metabolic pathways in the system. Finally, the smog will be alleviated or eliminated because of reduction of nitrogen oxides emission. This study will produce the green developmental methodology.

  19. 40 CFR 60.46b - Compliance and performance test methods and procedures for particulate matter and nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and procedures for particulate matter and nitrogen oxides. 60.46b Section 60.46b Protection of... nitrogen oxides. (a) The PM emission standards and opacity limits under § 60.43b apply at all times except... oil having a nitrogen content greater than 0.30 weight percent shall determine compliance with the NOX...

  20. 40 CFR 60.46b - Compliance and performance test methods and procedures for particulate matter and nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and procedures for particulate matter and nitrogen oxides. 60.46b Section 60.46b Protection of... nitrogen oxides. (a) The PM emission standards and opacity limits under § 60.43b apply at all times except... oil having a nitrogen content greater than 0.30 weight percent shall determine compliance with the NOX...

  1. Numerical modelling of emissions of nitrogen oxides in solid fuel combustion.

    PubMed

    Bešenić, Tibor; Mikulčić, Hrvoje; Vujanović, Milan; Duić, Neven

    2018-06-01

    Among the combustion products, nitrogen oxides are one of the main contributors to a negative impact on the environment, participating in harmful processes such as tropospheric ozone and acid rains production. The main source of emissions of nitrogen oxides is the human combustion of fossil fuels. Their formation models are investigated and implemented with the goal of obtaining a tool for studying the nitrogen-containing pollutant production. In this work, numerical simulation of solid fuel combustion was carried out on a three-dimensional model of a drop tube furnace by using the commercial software FIRE. It was used for simulating turbulent fluid flow and temperature field, concentrations of the reactants and products, as well as the fluid-particles interaction by numerically solving the integro-differential equations describing these processes. Chemical reactions mechanisms for the formation of nitrogen oxides were implemented by the user functions. To achieve reasonable calculation times for running the simulations, as well as efficient coupling with the turbulent mixing process, the nitrogen scheme is limited to sufficiently few homogeneous reactions and species. Turbulent fluctuations that affect the reaction rates of nitrogen oxides' concentration are modelled by probability density function approach. Results of the implemented model for nitrogen oxides' formation from coal and biomass are compared to the experimental data. Temperature, burnout and nitrogen oxides' concentration profiles are compared, showing satisfactory agreement. The new model allows the simulation of pollutant formation in the real-world applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Multi-stage catalyst systems and uses thereof

    DOEpatents

    Ozkan, Umit S [Worthington, OH; Holmgreen, Erik M [Columbus, OH; Yung, Matthew M [Columbus, OH

    2009-02-10

    Catalyst systems and methods provide benefits in reducing the content of nitrogen oxides in a gaseous stream containing nitric oxide (NO), hydrocarbons, carbon monoxide (CO), and oxygen (O.sub.2). The catalyst system comprises an oxidation catalyst comprising a first metal supported on a first inorganic oxide for catalyzing the oxidation of NO to nitrogen dioxide (NO.sub.2), and a reduction catalyst comprising a second metal supported on a second inorganic oxide for catalyzing the reduction of NO.sub.2 to nitrogen (N.sub.2).

  3. Effect of Nitrogen Source on Growth and Trichloroethylene Degradation by Methane-Oxidizing Bacteria

    PubMed Central

    Chu, Kung-Hui; Alvarez-Cohen, Lisa

    1998-01-01

    The effect of nitrogen source on methane-oxidizing bacteria with respect to cellular growth and trichloroethylene (TCE) degradation ability were examined. One mixed chemostat culture and two pure type II methane-oxidizing strains, Methylosinus trichosporium OB3b and strain CAC-2, which was isolated from the chemostat culture, were used in this study. All cultures were able to grow with each of three different nitrogen sources: ammonia, nitrate, and molecular nitrogen. Both M. trichosporium OB3b and strain CAC-2 showed slightly lower net cellular growth rates and cell yields but exhibited higher methane uptake rates, levels of poly-β-hydroxybutyrate (PHB) production, and naphthalene oxidation rates when grown under nitrogen-fixing conditions. The TCE-degrading ability of each culture was measured in terms of initial TCE oxidation rates and TCE transformation capacities (mass of TCE degraded/biomass inactivated), measured both with and without external energy sources. Higher initial TCE oxidation rates and TCE transformation capacities were observed in nitrogen-fixing mixed, M. trichosporium OB3b, and CAC-2 cultures than in nitrate- or ammonia-supplied cells. TCE transformation capacities were found to correlate with cellular PHB content in all three cultures. The results of this study suggest that the nitrogen-fixing capabilities of methane-oxidizing bacteria can be used to select for high-activity TCE degraders for the enhancement of bioremediation in fixed-nitrogen-limited environments. PMID:9726896

  4. Community Composition of Nitrous Oxide-Related Genes in Salt Marsh Sediments Exposed to Nitrogen Enrichment.

    PubMed

    Angell, John H; Peng, Xuefeng; Ji, Qixing; Craick, Ian; Jayakumar, Amal; Kearns, Patrick J; Ward, Bess B; Bowen, Jennifer L

    2018-01-01

    Salt marshes provide many key ecosystem services that have tremendous ecological and economic value. One critical service is the removal of fixed nitrogen from coastal waters, which limits the negative effects of eutrophication resulting from increased nutrient supply. Nutrient enrichment of salt marsh sediments results in higher rates of nitrogen cycling and, commonly, a concurrent increase in the flux of nitrous oxide, an important greenhouse gas. Little is known, however, regarding controls on the microbial communities that contribute to nitrous oxide fluxes in marsh sediments. To address this disconnect, we generated profiles of microbial communities and communities of micro-organisms containing specific nitrogen cycling genes that encode several enzymes ( amoA, norB, nosZ) related to nitrous oxide flux from salt marsh sediments. We hypothesized that communities of microbes responsible for nitrogen transformations will be structured by nitrogen availability. Taxa that respond positively to high nitrogen inputs may be responsible for the elevated rates of nitrogen cycling processes measured in fertilized sediments. Our data show that, with the exception of ammonia-oxidizing archaea, the community composition of organisms involved in the production and consumption of nitrous oxide was altered under nutrient enrichment. These results suggest that previously measured rates of nitrous oxide production and consumption are likely the result of changes in community structure, not simply changes in microbial activity.

  5. 40 CFR 52.992 - Area-wide nitrogen oxides exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Area-wide nitrogen oxides exemptions. 52.992 Section 52.992 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... nitrogen oxides exemptions. (a) The Louisiana Department of Environmental Quality submitted to the EPA on...

  6. 40 CFR 52.2308 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Area-wide nitrogen oxides (NOX) exemptions. 52.2308 Section 52.2308 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...-wide nitrogen oxides (NOX) exemptions. (a) The Texas Natural Resource Conservation Commission (TNRCC...

  7. 40 CFR 52.992 - Area-wide nitrogen oxides exemptions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Area-wide nitrogen oxides exemptions. 52.992 Section 52.992 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... nitrogen oxides exemptions. (a) The Louisiana Department of Environmental Quality submitted to the EPA on...

  8. 40 CFR 52.2308 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Area-wide nitrogen oxides (NOX) exemptions. 52.2308 Section 52.2308 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...-wide nitrogen oxides (NOX) exemptions. (a) The Texas Natural Resource Conservation Commission (TNRCC...

  9. 40 CFR 52.992 - Area-wide nitrogen oxides exemptions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Area-wide nitrogen oxides exemptions. 52.992 Section 52.992 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... nitrogen oxides exemptions. (a) The Louisiana Department of Environmental Quality submitted to the EPA on...

  10. 40 CFR 52.992 - Area-wide nitrogen oxides exemptions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Area-wide nitrogen oxides exemptions. 52.992 Section 52.992 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... nitrogen oxides exemptions. (a) The Louisiana Department of Environmental Quality submitted to the EPA on...

  11. 40 CFR 52.2308 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Area-wide nitrogen oxides (NOX) exemptions. 52.2308 Section 52.2308 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...-wide nitrogen oxides (NOX) exemptions. (a) The Texas Natural Resource Conservation Commission (TNRCC...

  12. 40 CFR 52.277 - Oxides of nitrogen, combustion gas concentration limitations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Oxides of nitrogen, combustion gas concentration limitations. 52.277 Section 52.277 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Oxides of nitrogen, combustion gas concentration limitations. (a) The following rules are being retained...

  13. 40 CFR 52.277 - Oxides of nitrogen, combustion gas concentration limitations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Oxides of nitrogen, combustion gas concentration limitations. 52.277 Section 52.277 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Oxides of nitrogen, combustion gas concentration limitations. (a) The following rules are being retained...

  14. 40 CFR 52.277 - Oxides of nitrogen, combustion gas concentration limitations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Oxides of nitrogen, combustion gas concentration limitations. 52.277 Section 52.277 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Oxides of nitrogen, combustion gas concentration limitations. (a) The following rules are being retained...

  15. 40 CFR 52.277 - Oxides of nitrogen, combustion gas concentration limitations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Oxides of nitrogen, combustion gas concentration limitations. 52.277 Section 52.277 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Oxides of nitrogen, combustion gas concentration limitations. (a) The following rules are being retained...

  16. 40 CFR 52.277 - Oxides of nitrogen, combustion gas concentration limitations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Oxides of nitrogen, combustion gas concentration limitations. 52.277 Section 52.277 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Oxides of nitrogen, combustion gas concentration limitations. (a) The following rules are being retained...

  17. 40 CFR 52.1876 - Control strategy: Nitrogen dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Control strategy: Nitrogen dioxide. 52...: Nitrogen dioxide. (a) The condition to EPA's approval of the oxides of nitrogen State Implementation Plan... change to the flow control date in the oxides of nitrogen budget trading SIP. (b) [Reserved] [69 FR 13234...

  18. 40 CFR 52.1876 - Control strategy: Nitrogen dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Control strategy: Nitrogen dioxide. 52...: Nitrogen dioxide. (a) The condition to EPA's approval of the oxides of nitrogen State Implementation Plan... change to the flow control date in the oxides of nitrogen budget trading SIP. (b) [Reserved] [69 FR 13234...

  19. 40 CFR 52.1876 - Control strategy: Nitrogen dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Control strategy: Nitrogen dioxide. 52...: Nitrogen dioxide. (a) The condition to EPA's approval of the oxides of nitrogen State Implementation Plan... change to the flow control date in the oxides of nitrogen budget trading SIP. (b) [Reserved] [69 FR 13234...

  20. 40 CFR 52.1876 - Control strategy: Nitrogen dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Control strategy: Nitrogen dioxide. 52...: Nitrogen dioxide. (a) The condition to EPA's approval of the oxides of nitrogen State Implementation Plan... change to the flow control date in the oxides of nitrogen budget trading SIP. (b) [Reserved] [69 FR 13234...

  1. Reduction of nitrogen oxides with catalytic acid resistant aluminosilicate molecular sieves and ammonia

    DOEpatents

    Pence, Dallas T.; Thomas, Thomas R.

    1980-01-01

    Noxious nitrogen oxides in a waste gas stream such as the stack gas from a fossil-fuel-fired power generation plant or other industrial plant off-gas stream is catalytically reduced to elemental nitrogen and/or innocuous nitrogen oxides employing ammonia as reductant in the presence of a zeolite catalyst in the hydrogen or sodium form having pore openings of about 3 to 10 A.

  2. 78 FR 46552 - Approval and Promulgation of Air Quality Implementation Plans; Massachusetts; Regulations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-01

    ... Volatile Organic Compounds and Nitrogen Oxides AGENCY: Environmental Protection Agency (EPA). ACTION... requirements for stationary sources of volatile organic compounds (VOCs) and nitrogen oxides (NO X ). This... to 310 CMR 7.19, Reasonably Available Control Technology (RACT) for Sources of Oxides of Nitrogen (NO...

  3. 40 CFR 52.2351 - Area-wide nitrogen oxides (NOX) exemption.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Area-wide nitrogen oxides (NOX) exemption. 52.2351 Section 52.2351 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... nitrogen oxides (NOX) exemption. On May 2, 1997, Ursula Trueman, Director, Division of Air Quality, Utah...

  4. 40 CFR 52.2351 - Area-wide nitrogen oxides (NOX) exemption.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Area-wide nitrogen oxides (NOX) exemption. 52.2351 Section 52.2351 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... nitrogen oxides (NOX) exemption. On May 2, 1997, Ursula Trueman, Director, Division of Air Quality, Utah...

  5. 40 CFR 52.2351 - Area-wide nitrogen oxides (NOX) exemption.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Area-wide nitrogen oxides (NOX) exemption. 52.2351 Section 52.2351 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... nitrogen oxides (NOX) exemption. On May 2, 1997, Ursula Trueman, Director, Division of Air Quality, Utah...

  6. 40 CFR 52.2351 - Area-wide nitrogen oxides (NOX) exemption.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Area-wide nitrogen oxides (NOX) exemption. 52.2351 Section 52.2351 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... nitrogen oxides (NOX) exemption. On May 2, 1997, Ursula Trueman, Director, Division of Air Quality, Utah...

  7. 40 CFR 52.2351 - Area-wide nitrogen oxides (NOX) exemption.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Area-wide nitrogen oxides (NOX) exemption. 52.2351 Section 52.2351 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... nitrogen oxides (NOX) exemption. On May 2, 1997, Ursula Trueman, Director, Division of Air Quality, Utah...

  8. 40 CFR 60.72 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for nitrogen oxides. 60.72 Section 60.72 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Plants § 60.72 Standard for nitrogen oxides. (a) On and after the date on which the performance test...

  9. 40 CFR 89.112 - Oxides of nitrogen, carbon monoxide, hydrocarbon, and particulate matter exhaust emission standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., hydrocarbon, and particulate matter exhaust emission standards. 89.112 Section 89.112 Protection of....112 Oxides of nitrogen, carbon monoxide, hydrocarbon, and particulate matter exhaust emission... emissions of oxides of nitrogen, carbon monoxide, hydrocarbon, and nonmethane hydrocarbon are measured using...

  10. 40 CFR 89.112 - Oxides of nitrogen, carbon monoxide, hydrocarbon, and particulate matter exhaust emission standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., hydrocarbon, and particulate matter exhaust emission standards. 89.112 Section 89.112 Protection of....112 Oxides of nitrogen, carbon monoxide, hydrocarbon, and particulate matter exhaust emission... emissions of oxides of nitrogen, carbon monoxide, hydrocarbon, and nonmethane hydrocarbon are measured using...

  11. Controls for maintaining low nitrogen oxides content in internal combustion engine exhaust gases

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Siebke, H.; Moro, B.; Schoenborn, M.

    1976-08-10

    A control system and apparatus for measuring and monitoring the nitrogen oxides content of internal combustion engine exhaust gases is described. The exhaust gases are contacted with the reducing electrode of a sensor cell having a predetermined potential established between the cell electrodes so that the reducing electrode is able to reduce both the nitrogen oxides and oxygen content of the exhaust gas. The current flowing through the sensor cell is measured to determine whether the nitrogen oxides content of the exhaust gas is sufficiently low.

  12. Catalysts for lean burn engine exhaust abatement

    DOEpatents

    Ott, Kevin C.; Clark, Noline C.; Paffett, Mark T.

    2006-08-01

    The present invention provides a process for catalytically reducing nitrogen oxides in an exhaust gas stream containing nitrogen oxides and a reductant material by contacting the gas stream under conditions effective to catalytically reduce the nitrogen oxides with a catalyst comprising a aluminum-silicate type material and a minor amount of a metal, the catalyst characterized as having sufficient catalytic activity so as to reduce the nitrogen oxides by at least 60 percent under temperatures within the range of from about 200.degree. C. to about 400.degree. C.

  13. Catalysts For Lean Burn Engine Exhaust Abatement

    DOEpatents

    Ott, Kevin C.; Clark, Noline C.; Paffett, Mark T.

    2004-04-06

    The present invention provides a process for catalytically reducing nitrogen oxides in an exhaust gas stream containing nitrogen oxides and a reductant material by contacting the gas stream under conditions effective to catalytically reduce the nitrogen oxides with a catalyst comprising a aluminum-silicate type material and a minor amount of a metal, the catalyst characterized as having sufficient catalytic activity so as to reduce the nitrogen oxides by at least 60 percent under temperatures within the range of from about 200.degree. C. to about 400.degree. C.

  14. Catalysts for lean burn engine exhaust abatement

    DOEpatents

    Ott, Kevin C.; Clark, Noline C.; Paffett, Mark T.

    2003-01-01

    The present invention provides a process for catalytically reducing nitrogen oxides in an exhaust gas stream containing nitrogen oxides and a reductant material by contacting the gas stream under conditions effective to catalytically reduce the nitrogen oxides with a catalyst comprising a aluminum-silicate type material and a minor amount of a metal, the catalyst characterized as having sufficient catalytic activity so as to reduce the nitrogen oxides by at least 60 percent under temperatures within the range of from about 200.degree. C. to about 400.degree. C.

  15. Atmospheric Ionization by Solar Particles Detected by Nitrate Measurements in Antarctic Snow. FY91 AASERT

    NASA Technical Reports Server (NTRS)

    Vitt, Francis M.; Jackman, Charles H.

    1995-01-01

    The odd nitrogen source strengths associated with Solar Proton Events (SPEs), Galactic Cosmic Rays (GCRs), and the oxidation of nitrous oxide in the Earth's middle atmosphere from 1974 through 1993 have been compared globally, at middle and lower latitudes (less than 50 deg), and polar regions (greater than 50 deg) with a two-dimensional (2-D) photochemical transport model. As discovered previously, the oxidation of nitrous oxide dominates the global odd nitrogen source while GCRs and SPEs are significant at polar latitudes. The horizontal transport of odd nitrogen, produced by the oxidation of nitrous oxide at latitudes < 50 deg, was found to be the dominant source of odd nitrogen in the polar regions with GCRs contributing substantially during the entire solar cycle. The source of odd nitrogen from SPEs was more sporadic; however, contributions during several years (mostly near solar maximum) were significant in the polar middle atmosphere.

  16. Method for combined removal of mercury and nitrogen oxides from off-gas streams

    DOEpatents

    Mendelsohn, Marshall H [Downers Grove, IL; Livengood, C David [Lockport, IL

    2006-10-10

    A method for removing elemental Hg and nitric oxide simultaneously from a gas stream is provided whereby the gas stream is reacted with gaseous chlorinated compound to convert the elemental mercury to soluble mercury compounds and the nitric oxide to nitrogen dioxide. The method works to remove either mercury or nitrogen oxide in the absence or presence of each other.

  17. 40 CFR 52.65 - Control Strategy: Nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Control Strategy: Nitrogen oxides. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Alabama § 52.65 Control Strategy: Nitrogen... using to implement provisions of the Prevention of Significant Deterioration regulations for nitrogen...

  18. 40 CFR 52.65 - Control Strategy: Nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Control Strategy: Nitrogen oxides. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Alabama § 52.65 Control Strategy: Nitrogen... using to implement provisions of the Prevention of Significant Deterioration regulations for nitrogen...

  19. 40 CFR 52.65 - Control Strategy: Nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Control Strategy: Nitrogen oxides. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Alabama § 52.65 Control Strategy: Nitrogen... using to implement provisions of the Prevention of Significant Deterioration regulations for nitrogen...

  20. 40 CFR 52.65 - Control Strategy: Nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Control Strategy: Nitrogen oxides. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Alabama § 52.65 Control Strategy: Nitrogen... using to implement provisions of the Prevention of Significant Deterioration regulations for nitrogen...

  1. Simulation of the impact of thunderstorm activity on atmospheric gas composition

    NASA Astrophysics Data System (ADS)

    Smyshlyaev, S. P.; Mareev, E. A.; Galin, V. Ya.

    2010-08-01

    A chemistry-climate model of the lower and middle atmosphere has been used to estimate the sensitivity of the atmospheric gas composition to the rate of thunderstorm production of nitrogen oxides at upper tropospheric and lower stratospheric altitudes. The impact that nitrogen oxides produced by lightning have on the atmospheric gas composition is treated as a subgrid-scale process and included in the model parametrically. The natural uncertainty in the global production rate of nitrogen oxides in lightning flashes was specified within limits from 2 to 20 Tg N/year. Results of the model experiments have shown that, due to the variability of thunderstorm-produced nitrogen oxides, their concentration in the upper troposphere and lower stratosphere can vary by a factor of 2 or 3, which, given the influence of nitrogen oxides on ozone and other gases, creates the potential for a strong perturbation of the atmospheric gas composition and thermal regime. Model calculations have shown the strong sensitivity of ozone and the OH hydroxyl to the amount of lightning nitrogen oxides at different atmospheric altitudes. These calculations demonstrate the importance of nitrogen oxides of thunderstorm origin for the balance of atmospheric odd ozone and gases linked to it, such as ozone and hydroxyl radicals. Our results demonstrate that one important task is to raise the accuracy of estimates of the rate of nitrogen oxide production by lightning discharges and to use physical parametrizations that take into account the local lightning effects and feedbacks arising in this case rather than climatological data in models of the gas composition and general circulation of the atmosphere.

  2. Flume experiments elucidate relationships between microbial genetics, nitrogen species and hydraulics in controlling nitrous oxide production in the hyporheic zone

    NASA Astrophysics Data System (ADS)

    Quick, A. M.; Farrell, T. B.; Reeder, W. J.; Feris, K. P.; Tonina, D.; Benner, S. G.

    2014-12-01

    The hyporheic zone is a potentially important producer of nitrous oxide, a powerful greenhouse gas. The location and magnitude of nitrous oxide generation within the hyporheic zone involves complex interactions between multiple nitrogen species, redox conditions, microbial communities, and hydraulics. To better understand nitrous oxide generation and emissions from streams, we conducted large-scale flume experiments in which we monitored pore waters along hyporheic flow paths within stream dune structures. Measured dissolved oxygen, ammonia, nitrate, nitrite, and dissolved nitrous oxide showed distinct spatial relationships reflecting redox changes along flow paths. Denitrifying genes (nosZ, nirS, and nirK), determined using qPCR, were spatially associated with abundances of nitrogen species. Using residence times along a flow path, clear trends in oxygen conditions, genes encoding for microbial catalysis, and nitrogen species were observed. Hotspots of targeted genes correlated with hotspots for conversion of nitrogen species, including nitrous oxide production and conversion to dinitrogen. Trends were apparent regardless of dune size, allowing for the possibility to apply observed relationships to multiple streambed morphologies. Relating streambed morphology and loading of nitrogen species allows for prediction of nitrous oxide production in the hyporheic zone.

  3. 40 CFR 60.55a - Standard for nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for nitrogen oxides. 60.55a Section 60.55a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... § 60.55a Standard for nitrogen oxides. On and after the date on which the initial compliance test is...

  4. 78 FR 54813 - Approval and Promulgation of Air Quality Implementation Plans; Maine; Oxides of Nitrogen...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-06

    ... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 52 [EPA-R01-OAR-2012-0895; FRL- 9900-85-Region1] Approval and Promulgation of Air Quality Implementation Plans; Maine; Oxides of Nitrogen Exemption and... proposed Approval and Promulgation of Air Quality Implementation Plans; Maine; Oxides of Nitrogen Exemption...

  5. 40 CFR 77.6 - Penalties for excess emissions of sulfur dioxide and nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... sulfur dioxide and nitrogen oxides. 77.6 Section 77.6 Protection of Environment ENVIRONMENTAL PROTECTION... sulfur dioxide and nitrogen oxides. (a)(1) If excess emissions of sulfur dioxide occur at the affected... under paragraph (a)(1) of this section for any increase in excess emissions of sulfur dioxide determined...

  6. 40 CFR 77.6 - Penalties for excess emissions of sulfur dioxide and nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... sulfur dioxide and nitrogen oxides. 77.6 Section 77.6 Protection of Environment ENVIRONMENTAL PROTECTION... sulfur dioxide and nitrogen oxides. (a)(1) If excess emissions of sulfur dioxide occur at the affected... under paragraph (a)(1) of this section for any increase in excess emissions of sulfur dioxide determined...

  7. 40 CFR 77.6 - Penalties for excess emissions of sulfur dioxide and nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... sulfur dioxide and nitrogen oxides. 77.6 Section 77.6 Protection of Environment ENVIRONMENTAL PROTECTION... sulfur dioxide and nitrogen oxides. (a)(1) If excess emissions of sulfur dioxide occur at the affected... under paragraph (a)(1) of this section for any increase in excess emissions of sulfur dioxide determined...

  8. 40 CFR 77.6 - Penalties for excess emissions of sulfur dioxide and nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... sulfur dioxide and nitrogen oxides. 77.6 Section 77.6 Protection of Environment ENVIRONMENTAL PROTECTION... sulfur dioxide and nitrogen oxides. (a)(1) If excess emissions of sulfur dioxide occur at the affected... under paragraph (a)(1) of this section for any increase in excess emissions of sulfur dioxide determined...

  9. 40 CFR 60.332 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... from paragraph (a) of this section. (f) Stationary gas turbines using water or steam injection for... Turbines § 60.332 Standard for nitrogen oxides. (a) On and after the date on which the performance test... stationary gas turbine, any gases which contain nitrogen oxides in excess of: EC16NO91.020 where: STD...

  10. 40 CFR 60.332 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... from paragraph (a) of this section. (f) Stationary gas turbines using water or steam injection for... Turbines § 60.332 Standard for nitrogen oxides. (a) On and after the date on which the performance test... stationary gas turbine, any gases which contain nitrogen oxides in excess of: EC16NO91.020 where: STD...

  11. 40 CFR 60.332 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... from paragraph (a) of this section. (f) Stationary gas turbines using water or steam injection for... Turbines § 60.332 Standard for nitrogen oxides. (a) On and after the date on which the performance test... stationary gas turbine, any gases which contain nitrogen oxides in excess of: EC16NO91.020 where: STD...

  12. 40 CFR 60.332 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... from paragraph (a) of this section. (f) Stationary gas turbines using water or steam injection for... Turbines § 60.332 Standard for nitrogen oxides. (a) On and after the date on which the performance test... stationary gas turbine, any gases which contain nitrogen oxides in excess of: EC16NO91.020 where: STD...

  13. 40 CFR 60.332 - Standard for nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... from paragraph (a) of this section. (f) Stationary gas turbines using water or steam injection for... Turbines § 60.332 Standard for nitrogen oxides. (a) On and after the date on which the performance test... stationary gas turbine, any gases which contain nitrogen oxides in excess of: EC16NO91.020 where: STD...

  14. Catalyst for Decomposition of Nitrogen Oxides

    NASA Technical Reports Server (NTRS)

    Schryer, David R. (Inventor); Akyurtlu, Ates (Inventor); Jordan, Jeffrey D. (Inventor); Akyurtlu, Jale (Inventor)

    2015-01-01

    This invention relates generally to a platinized tin oxide-based catalyst. It relates particularly to an improved platinized tin oxide-based catalyst able to decompose nitric oxide to nitrogen and oxygen without the necessity of a reducing gas.

  15. U.S. nitrogen science plan focuses collaborative efforts

    NASA Astrophysics Data System (ADS)

    Holland, E. A.; Guenther, A.; Lee-Taylor, J.; Bertman, S. B.; Carroll, M. A.; Shepson, P. B.; Sparks, J. P.

    Nitrogen is a major nutrient in terrestrial ecosystems and an important catalyst in tropospheric photochemistry. Over the last century human activities have dramatically increased inputs of reactive nitrogen (Nr, the combination of oxidized, reduced, and organically bound nitrogen) to the Earth system (Figure 1). Nitrogen cycle perturbations have compromised air quality and human health, acidified ecosystems, and degraded and eutrophied lakes and coastal estuaries [Vitousek et al., 1997a, 1997b; Rabalais, 2002; Howarth et al., 2003; Townsend et al., 2003; Galloway et al., 2004].Increased Nr affects global climate. Use of agricultural fertilizers such as ammonium nitrate leads to increased soil production of nitrous oxide (N2O), which has 320 times the global warming potential of carbon dioxide (CO2). Emission of nitrogen oxides (NOx = nitric oxide, NO + nitrogen dioxide, NO2) from fossil fuel burning leads to increases in tropospheric ozone, another greenhouse gas. Ozone is phytotoxic, and may reduce terrestrial CO2 sequestration. To predict the effects of nitrogen cycling changes under changing climatic conditions, there needs to be a better understanding of the global nitrogen budget.

  16. Electrochemical process for the preparation of nitrogen fertilizers

    DOEpatents

    Jiang, Junhua; Aulich, Ted R; Ignatchenko, Alexey V

    2015-04-14

    Methods and apparatus for the preparation of nitrogen fertilizers including ammonium nitrate, urea, urea-ammonium nitrate, and/or ammonia are disclosed. Embodiments include (1) ammonium nitrate produced via the reduction of a nitrogen source at the cathode and the oxidation of a nitrogen source at the anode; (2) urea or its isomers produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source: (3) ammonia produced via the reduction of nitrogen source at the cathode and the oxidation of a hydrogen source or a hydrogen equivalent such as carbon monoxide or a mixture of carbon monoxide and hydrogen at the anode; and (4) urea-ammonium nitrate produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source, and anodic oxidation of a nitrogen source.

  17. Environmental Assessment: Construction and Operation of New Security Forces Facility at Hill Air Force Base, Utah

    DTIC Science & Technology

    2008-10-01

    Quality Standards NEPA National Environmental Policy Act of 1969 NOx Nitrogen Oxides OO-ALC Ogden Air Logistics Center OSHA Occupational Safety...current NAAQS. These standards regulate six common pollutants: carbon monoxide, lead, nitrogen oxides, sulfur oxides, ozone, and particulate matter...with the state plan. The conformity threshold emission level for ozone in maintenance areas is 100 tons per year for nitrogen oxide (NOx) and volatile

  18. PHOTOCATALYTIC SELECTIVE OXIDATION OF HYDROCARBONS IN THE AQUEOUS PHASE

    EPA Science Inventory

    The sustainable transformation of an inert alkane into its corresponding oxygenates has been the subject of intense chemical research. These oxygenates typically produced from processes using stringent conditions and materials offer disadvantages that include decreased selectivi...

  19. 40 CFR 62.14103 - Emission limits for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 62.14103 Section 62.14103 Protection of... combustor metals, acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals are specified in paragraphs (a)(1) through (a)(3) of this section. (1) The owner or...

  20. 40 CFR 52.770 - Identification of plan.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .../1980 11/5/1981, 46 FR 54943. 1-2-88 “Vapor balance system″ defined 9/26/1980 11/5/1981, 46 FR 54943. 1... Specific testing procedures; particulate matter; PM10; PM2.5; sulfur dioxide; nitrogen oxides; volatile.../2002 11/30/2004, 69 FR 69531. Article 10. Nitrogen Oxides Rules 10-1 Nitrogen Oxides Control in Clark...

  1. 40 CFR Table 2 to Subpart Fff of... - Nitrogen Oxides Requirements for Affected Facilities

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Nitrogen Oxides Requirements for Affected Facilities 2 Table 2 to Subpart FFF of Part 62 Protection of Environment ENVIRONMENTAL PROTECTION... Before September 20, 1994 Pt. 62, Subpt. FFF, Table 2 Table 2 to Subpart FFF of Part 62—Nitrogen Oxides...

  2. 40 CFR 60.4320 - What emission limits must I meet for nitrogen oxides (NOX)?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What emission limits must I meet for nitrogen oxides (NOX)? 60.4320 Section 60.4320 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... nitrogen oxides (NOX)? (a) You must meet the emission limits for NOX specified in Table 1 to this subpart...

  3. The Oxides of Nitrogen in Air Pollution.

    ERIC Educational Resources Information Center

    California State Air Resources Board, Sacramento.

    Research on the health effects of oxides of nitrogen and on the role of oxides of nitrogen in producing photochemical smog effects is presented in this report. Prepared by the California State Department of Public Health at the request of the State Legislature, it gives a comprehensive review of available information, as well as the need for air…

  4. 40 CFR 60.4320 - What emission limits must I meet for nitrogen oxides (NOX)?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false What emission limits must I meet for nitrogen oxides (NOX)? 60.4320 Section 60.4320 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... nitrogen oxides (NOX)? (a) You must meet the emission limits for NOX specified in Table 1 to this subpart...

  5. 40 CFR 60.4320 - What emission limits must I meet for nitrogen oxides (NOX)?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false What emission limits must I meet for nitrogen oxides (NOX)? 60.4320 Section 60.4320 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... nitrogen oxides (NOX)? (a) You must meet the emission limits for NOX specified in Table 1 to this subpart...

  6. 40 CFR 60.4320 - What emission limits must I meet for nitrogen oxides (NOX)?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false What emission limits must I meet for nitrogen oxides (NOX)? 60.4320 Section 60.4320 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... nitrogen oxides (NOX)? (a) You must meet the emission limits for NOX specified in Table 1 to this subpart...

  7. 40 CFR 60.4320 - What emission limits must I meet for nitrogen oxides (NOX)?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false What emission limits must I meet for nitrogen oxides (NOX)? 60.4320 Section 60.4320 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... nitrogen oxides (NOX)? (a) You must meet the emission limits for NOX specified in Table 1 to this subpart...

  8. 40 CFR 60.46b - Compliance and performance test methods and procedures for particulate matter and nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... and procedures for particulate matter and nitrogen oxides. 60.46b Section 60.46b Protection of... NEW STATIONARY SOURCES Standards of Performance for Industrial-Commercial-Institutional Steam... nitrogen oxides. (a) The PM emission standards and opacity limits under § 60.43b apply at all times except...

  9. Electrochemical process for the preparation of nitrogen fertilizers

    DOEpatents

    Aulich, Ted R.; Olson, Edwin S.; Jiang, Junhua

    2013-03-19

    The present invention provides methods and apparatus for the preparation of nitrogen fertilizers including ammonium nitrate, urea, urea-ammonium nitrate, and/or ammonia utilizing a source of carbon, a source of nitrogen, and/or a source of hydrogen. Implementing an electrolyte serving as ionic charge carrier, (1) ammonium nitrate is produced via the reduction of a nitrogen source at the cathode and the oxidation of a nitrogen source at the anode; (2) urea or its isomers are produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source; (3) ammonia is produced via the reduction of nitrogen source at the cathode and the oxidation of a hydrogen source at the anode; and (4) urea-ammonium nitrate is produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source, and anodic oxidation of a nitrogen source. The electrolyte can be solid.

  10. Method For Selective Catalytic Reduction Of Nitrogen Oxides

    DOEpatents

    Mowery-Evans, Deborah L.; Gardner, Timothy J.; McLaughlin, Linda I.

    2005-02-15

    A method for catalytically reducing nitrogen oxide compounds (NO.sub.x, defined as nitric oxide, NO, +nitrogen dioxide, NO.sub.2) in a gas by a material comprising a base metal consisting essentially of CuO and Mn, and oxides of Mn, on an activated metal hydrous metal oxide support, such as HMO:Si. A promoter, such as tungsten oxide or molybdenum oxide, can be added and has been shown to increase conversion efficiency. This method provides good conversion of NO.sub.x to N.sub.2, good selectivity, good durability, resistance to SO.sub.2 aging and low toxicity compared with methods utilizing vanadia-based catalysts.

  11. Method for selective catalytic reduction of nitrogen oxides

    DOEpatents

    Mowery-Evans, Deborah L [Broomfield, CO; Gardner, Timothy J [Albuquerque, NM; McLaughlin, Linda I [Albuquerque, NM

    2005-02-15

    A method for catalytically reducing nitrogen oxide compounds (NO.sub.x, defined as nitric oxide, NO, +nitrogen dioxide, NO.sub.2) in a gas by a material comprising a base metal consisting essentially of CuO and Mn, and oxides of Mn, on an activated metal hydrous metal oxide support, such as HMO:Si. A promoter, such as tungsten oxide or molybdenum oxide, can be added and has been shown to increase conversion efficiency. This method provides good conversion of NO.sub.x to N.sub.2, good selectivity, good durability, resistance to SO.sub.2 aging and low toxicity compared with methods utilizing vanadia-based catalysts.

  12. Study Uncovers Dirty Little Secret: Soil Emissions are Much-Bigger-than-Expected Component of Air Pollution

    NASA Technical Reports Server (NTRS)

    Stricherz, Vince

    2005-01-01

    Nitrogen oxides produced by huge fires and fossil fuel combustion are a major component of air pollution. They are the primary ingredients in ground-level ozone, a pollutant harmful to human health and vegetation. But new research led by a University of Washington atmospheric scientist shows that, in some regions, nitrogen oxides emitted by the soil are much greater than expected and could play a substantially larger role in seasonal air pollution than previously believed. Nitrogen oxide emissions total more than 40 million metric tons worldwide each year, with 64 percent coming from fossil fuel combustion, 14 percent from burning and a surprising 22 percent from soil, said Lyatt Jaegle, a UW assistant professor of atmospheric sciences. The new research shows that the component from soil is about 70 percent greater than scientists expected. Instead of relying on scattered ground-based measurements of burning and combustion and then extrapolating a global total for nitrogen oxide emissions, the new work used actual observations recorded in 2000 by the Global Ozone Monitoring Experiment aboard the European Space Agency's European Remote Sensing 2 satellite. Nitrogen oxide emissions from fossil fuel combustion are most closely linked to major population centers and show up in the satellite's ozone-monitoring measurements of nitrogen dioxide, part of the nitrogen oxides family.

  13. Cross-system comparisons of soil nitrogen transformations and nitrous oxide flux in tropical forest ecosystems

    NASA Technical Reports Server (NTRS)

    Matson, Pamela A.; Vitousek, Peter M.

    1987-01-01

    Soil nitrogen transformations and nitrous oxide flux across the soil-air interface have been measured in a variety of tropical forest sites and correlated with patterns of nitrogen circulation. Nitrogen mineralizaton and nitrification potentials were found to be high in the relatively fertile Costa Rica sites and the Amazonian oxisol/ultisols, intermediate in Amazonian white sand soils, and low in the Hawaiian montane sites. Nitrous oxide fluxes ranged from 0 to 6.2 ng/sq cm per h, and the mean flux per site was shown to be highly correlated with mean nitrogen mineralization.

  14. Impact of a nitrogen emission control area (NECA) for ship traffic on the future air quality in the Baltic Sea region

    NASA Astrophysics Data System (ADS)

    Karl, Matthias; Geyer, Beate; Bieser, Johannes; Matthias, Volker; Quante, Markus; Jalkanen, Jukka-Pekka; Johansson, Lasse; Fridell, Erik

    2017-04-01

    Deposition of nitrogen compounds originating from shipping activities contribute to eutrophication of the Baltic Sea and coastal areas in the Baltic Sea region. Emissions of nitrogen oxides (NOx) from shipping on the Baltic Sea are comparable to the combined land-based emissions of NOx from Finland and Sweden and have been relatively stable over the last decade. However, expected future growth of maritime transport will result in higher fuel consumption and, if not compensated by increased transport efficiency or other measures, lead to higher total emissions of NOx from shipping. For the Baltic Sea a nitrogen emission control area (NECA) will become effective in 2021 - permitting only new built ships that are compliant with stringent Tier III emission limits - with the target of reducing NOx-emissions. In order to study the effect of implementing a Baltic Sea NECA-2021 on air quality and nitrogen deposition two future scenarios were designed; one with implementation of a NECA for the Baltic Sea starting in 2021 and another with no NECA implemented. The same increase of ship traffic was assumed for both future scenarios. Since complete fleet renewal with low NOx-emitting engines is not expected until 20-30 years after the NECA entry date, year 2040 was chosen as future scenario year. The Community Multiscale Air Quality (CMAQ) model was used to simulate the current and future air quality situation. The nested simulation runs with CMAQ were performed on a horizontal resolution of 4 km × 4 km for the entire Baltic Sea region. The meteorological year 2012 was chosen for the simulation of the current and future air quality situation since the 2m-temperature and precipitation anomalies of 2012 are closely aligned to the 2004-2014 decadal average over Baltic Proper. High-resolution meteorology obtained from COSMO-CLM was used for the regional simulations. Ship emissions were generated with the Ship Traffic Emission Assessment Model (STEAM) by the Finnish Meteorological Institute (FMI) using the Automatic Identification System (AIS) network data to allocate ship positions. Gridded land-based emissions were taken from the SMOKE-EU model which is based on the official EMEP data. Future land-based emissions were reduced in accordance with current legislation. Model simulations for the current situation show that shipping emissions are the main contributor to ambient NO2 concentrations over the Baltic Sea. Shipping emissions are responsible for 40-70 % of the particulate nitrate concentrations during the summer months. Relative contribution of shipping emissions to monthly total nitrogen deposition, as a sum of oxidized and reduced nitrogen compounds, was highest in summer, with up to 60 % in the northern part of the Baltic Proper, while it was on average 10 % for other parts of the Baltic Sea. With the NECA in the Baltic Sea in effect from 2021, the reduction of reactive nitrogen concentrations and deposition in the Baltic Sea region compared to a scenario without Tier III regulations is significant.

  15. Method of removing oxides of sulfur and oxides of nitrogen from exhaust gases

    DOEpatents

    Walker, Richard J.

    1986-01-01

    A continuous method is presented for removing both oxides of sulfur and oxides of nitrogen from combustion or exhaust gases with the regeneration of the absorbent. Exhaust gas is cleaned of particulates and HCl by a water scrub prior to contact with a liquid absorbent that includes an aqueous solution of bisulfite and sulfite ions along with a metal chelate, such as, an iron or zinc aminopolycarboxylic acid. Following contact with the combustion gases the spent absorbent is subjected to electrodialysis to transfer bisulfite ions into a sulfuric acid solution while splitting water with hydroxide and hydrogen ion migration to equalize electrical charge. The electrodialysis stack includes alternate layers of anion selective and bipolar membranes. Oxides of nitrogen are removed from the liquid absorbent by air stripping at an elevated temperature and the regenerated liquid absorbent is returned to contact with exhaust gases for removal of sulfur oxides and nitrogen oxides.

  16. ATMOSPHERIC NITROGEN FIXATION BY METHANE-OXIDIZING BACTERIA

    PubMed Central

    Davis, J. B.; Coty, V. F.; Stanley, J. P.

    1964-01-01

    Davis, J. B. (Socony Mobil Oil Co., Inc., Dallas, Tex.), V. F. Coty, and J. P. Stanley. Atmospheric nitrogen fixation by methane-oxidizing bacteria. J. Bacteriol. 88:468–472. 1964.—Methane-oxidizing bacteria capable of fixing atmospheric nitrogen were isolated from garden soil, pond mud, oil field soil, and soil exposed to natural gas, indicating a rather wide prevalence in nature. This may explain the high concentration of organic nitrogen commonly found in soils exposed to gas leakage from pipelines or natural-gas seeps. Added molybdenum was a requirement for growth in a nitrogen-free mineral salts medium. All nitrogen-fixing, methane-oxidizing bacteria isolated were gram-negative, nonsporeforming, usually motile rods. Colonies were light yellow, yellow, or white. The most common isolate, which formed light-yellow colonies, is referred to as Pseudomonas methanitrificans sp. n., and is distinguished from Pseudomonas (Methanomonas) methanica by nitrogen-fixing ability and a preponderance of poly-β-hydroxybutyrate in the cellular lipid fraction. Images PMID:14203365

  17. 40 CFR 52.38 - What are the requirements of the Federal Implementation Plans (FIPs) under the Transport Rule (TR...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Federal Implementation Plans (FIPs) under the Transport Rule (TR) relating to emissions of nitrogen oxides... emissions of nitrogen oxides? (a)(1) The TR NOX Annual Trading Program provisions set forth in subpart AAAAA... annual emissions of nitrogen oxides (NOX). (2) The provisions of subpart AAAAA of part 97 of this chapter...

  18. 40 CFR 52.35 - What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... nitrogen oxides? 52.35 Section 52.35 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... (CAIR) relating to emissions of nitrogen oxides? (a)(1) The Federal CAIR NOX Annual Trading Program... provisions that relate to annual emissions of nitrogen oxides (NOX). Each State that is described in § 51.123...

  19. 40 CFR 52.38 - What are the requirements of the Federal Implementation Plans (FIPs) under the Transport Rule (TR...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Federal Implementation Plans (FIPs) under the Transport Rule (TR) relating to emissions of nitrogen oxides... emissions of nitrogen oxides? (a)(1) The TR NOX Annual Trading Program provisions set forth in subpart AAAAA... annual emissions of nitrogen oxides (NOX). (2) The provisions of subpart AAAAA of part 97 of this chapter...

  20. 40 CFR 52.35 - What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... nitrogen oxides? 52.35 Section 52.35 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... (CAIR) relating to emissions of nitrogen oxides? (a)(1) The Federal CAIR NOX Annual Trading Program... provisions that relate to annual emissions of nitrogen oxides (NOX). Each State that is described in § 51.123...

  1. 40 CFR 52.35 - What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... nitrogen oxides? 52.35 Section 52.35 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... (CAIR) relating to emissions of nitrogen oxides? (a)(1) The Federal CAIR NOX Annual Trading Program... provisions that relate to annual emissions of nitrogen oxides (NOX). Each State that is described in § 51.123...

  2. 40 CFR 52.35 - What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... nitrogen oxides? 52.35 Section 52.35 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... (CAIR) relating to emissions of nitrogen oxides? (a)(1) The Federal CAIR NOX Annual Trading Program... provisions that relate to annual emissions of nitrogen oxides (NOX). Each State that is described in § 51.123...

  3. 40 CFR 52.38 - What are the requirements of the Federal Implementation Plans (FIPs) under the Transport Rule (TR...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Federal Implementation Plans (FIPs) under the Transport Rule (TR) relating to emissions of nitrogen oxides... emissions of nitrogen oxides? (a)(1) The TR NOX Annual Trading Program provisions set forth in subpart AAAAA... annual emissions of nitrogen oxides (NOX). (2) The provisions of subpart AAAAA of part 97 of this chapter...

  4. 40 CFR 52.35 - What are the requirements of the Federal Implementation Plans (FIPs) for the Clean Air Interstate...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... nitrogen oxides? 52.35 Section 52.35 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... (CAIR) relating to emissions of nitrogen oxides? (a)(1) The Federal CAIR NOX Annual Trading Program... provisions that relate to annual emissions of nitrogen oxides (NOX). Each State that is described in § 51.123...

  5. Arginase Inhibitor in the Pharmacological Correction of Endothelial Dysfunction

    PubMed Central

    Pokrovskiy, Mihail V.; Korokin, Mihail V.; Tsepeleva, Svetlana A.; Pokrovskaya, Tatyana G.; Gureev, Vladimir V.; Konovalova, Elena A.; Gudyrev, Oleg S.; Kochkarov, Vladimir I.; Korokina, Liliya V.; Dudina, Eleonora N.; Babko, Anna V.; Terehova, Elena G.

    2011-01-01

    This paper is about a way of correction of endothelial dysfunction with the inhibitor of arginase: L-norvaline. There is an imbalance between vasoconstriction and vasodilatation factors of endothelium on the basis of endothelial dysfunction. Among vasodilatation agents, nitrogen oxide plays the basic role. Amino acid L-arginine serves as a source of molecules of nitrogen oxide in an organism. Because of the high activity of arginase enzyme which catalyzes the hydrolysis of L-arginine into ornithine and urea, the bioavailability of nitrogen oxide decreases. The inhibitors of arginase suppress the activity of the given enzyme, raising and production of nitrogen oxide, preventing the development of endothelial dysfunction. PMID:21747978

  6. Defect pair formation in fluorine and nitrogen codoped TiO2

    NASA Astrophysics Data System (ADS)

    Kordatos, A.; Kelaidis, N.; Chroneos, A.

    2018-04-01

    Titanium oxide is extensively investigated because of its high chemical stability and its photocatalytic properties; nevertheless, the large band gap limits its activity to a small portion of the solar spectrum. Nitrogen and fluorine codoping is an efficient defect engineering strategy to increase the photocatalytic activity of titanium oxide. In the present study, we apply density functional theory to investigate the interaction of nitrogen with fluorine and the formation of defect pairs. We show that in fluorine and nitrogen codoped titanium oxide, the FiNi, FONi, and FiNTi defects can form. Their impact on the electronic structure of titanium oxide is discussed.

  7. Influence of dissolved gases and heat treatments on the oxidative degradation of polyunsaturated fatty acids enriched dairy beverage.

    PubMed

    Giroux, Hélène J; Acteau, Geneviève; Sabik, Hassan; Britten, Michel

    2008-07-23

    The combined effect of dissolved gas composition and heat treatment on the oxidative degradation of a dairy beverage enriched with 2% linseed oil was studied. The dairy beverage was saturated with air, nitrogen, or a nitrogen/hydrogen mixture (4% hydrogen) before pasteurization or sterilization. Saturation with either nitrogen or a nitrogen/hydrogen mixture decreased the dissolved oxygen concentration in dairy beverages (Delta = 7.7 ppm), and the presence of hydrogen significantly reduced the redox potential (Delta = 287 mV). Heat treatments also reduced the oxygen content and redox potential, sterilization being more effective than pasteurization. Both pasteurization and sterilization induced the oxidative degradation of the beverages. On average, the propanal concentration increased by a factor of 2.3 after pasteurization and by a factor of 6.2 after sterilization. However, during storage, sterilized beverages resisted light-induced oxidation better than unheated or pasteurized beverages. Furthermore, saturation with nitrogen or a nitrogen/hydrogen mixture significantly reduced oxidative degradation and provided some protection against color changes during storage.

  8. NITROGEN DIOXIDE, PULMONARY FUNCTION, AND RESPIRATORY DISEASE

    EPA Science Inventory

    Concern as to the toxicity of the oxides of nitrogen has been frequently expressed in clinical and toxicological literature. Oxides of nitrogen are highly reactive compounds and suggest toxic effects on biological systems. The earliest evidence for potential damage to man occurre...

  9. The Determination of Total Nitrogen Oxides in Stack Gases. Phenoldisulfonic Acid Method.

    ERIC Educational Resources Information Center

    Thorpe, Charles J. D.

    The well known Saltzman method for oxides of nitrogen is intended for the determination of these constituents in the ambient atmosphere in the range of a few parts per billion to about 5ppm. However, when sulfur dioxide is present in the gas to be sampled and/or the concentration range of the oxides of nitrogen is from five to several thousand…

  10. Regulated and unregulated emissions from modern 2010 emissions-compliant heavy-duty on-highway diesel engines

    PubMed Central

    Khalek, Imad A.; Blanks, Matthew G.; Merritt, Patrick M.; Zielinska, Barbara

    2015-01-01

    The U.S. Environmental Protection Agency (EPA) established strict regulations for highway diesel engine exhaust emissions of particulate matter (PM) and nitrogen oxides (NOx) to aid in meeting the National Ambient Air Quality Standards. The emission standards were phased in with stringent standards for 2007 model year (MY) heavy-duty engines (HDEs), and even more stringent NOX standards for 2010 and later model years. The Health Effects Institute, in cooperation with the Coordinating Research Council, funded by government and the private sector, designed and conducted a research program, the Advanced Collaborative Emission Study (ACES), with multiple objectives, including detailed characterization of the emissions from both 2007- and 2010-compliant engines. The results from emission testing of 2007-compliant engines have already been reported in a previous publication. This paper reports the emissions testing results for three heavy-duty 2010-compliant engines intended for on-highway use. These engines were equipped with an exhaust diesel oxidation catalyst (DOC), high-efficiency catalyzed diesel particle filter (DPF), urea-based selective catalytic reduction catalyst (SCR), and ammonia slip catalyst (AMOX), and were fueled with ultra-low-sulfur diesel fuel (~6.5 ppm sulfur). Average regulated and unregulated emissions of more than 780 chemical species were characterized in engine exhaust under transient engine operation using the Federal Test Procedure cycle and a 16-hr duty cycle representing a wide dynamic range of real-world engine operation. The 2010 engines’ regulated emissions of PM, NOX, nonmethane hydrocarbons, and carbon monoxide were all well below the EPA 2010 emission standards. Moreover, the unregulated emissions of polycyclic aromatic hydrocarbons (PAHs), nitroPAHs, hopanes and steranes, alcohols and organic acids, alkanes, carbonyls, dioxins and furans, inorganic ions, metals and elements, elemental carbon, and particle number were substantially (90 to >99%) lower than pre-2007-technology engine emissions, and also substantially (46 to >99%) lower than the 2007-technology engine emissions characterized in the previous study. Implications: Heavy-duty on-highway diesel engines equipped with DOC/DPF/SCR/AMOX and fueled with ultra-low-sulfur diesel fuel produced lower emissions than the stringent 2010 emission standards established by the U.S. Environmental Protection Agency. They also resulted in significant reductions in a wide range of unregulated toxic emission compounds relative to older technology engines. The increased use of newer technology (2010+) diesel engines in the on-highway sector and the adaptation of such technology by other sectors such as nonroad, displacing older, higher emissions engines, will have a positive impact on ambient levels of PM, NOx, and volatile organic compounds, in addition to many other toxic compounds. PMID:26037832

  11. 76 FR 29680 - Approval and Disapproval and Promulgation of State Implementation Plan Revisions; Infrastructure...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-23

    ... 10, Nitrogen oxides, approved by EPA May 31, 1972 (37 FR 10842). WAQSR, Section 4, Sulfur oxides..., approved by EPA on May 31, 1972 (37 FR 10842). WAQSR, Section 4, Sulfur oxides, approved by EPA June 10... standards for nitrogen oxides; Section 4, Emission standard for sulfur oxides; Section 5, Emission standards...

  12. Biological nitric oxide signalling: chemistry and terminology

    PubMed Central

    Heinrich, Tassiele A; da Silva, Roberto S; Miranda, Katrina M; Switzer, Christopher H; Wink, David A; Fukuto, Jon M

    2013-01-01

    Biological nitrogen oxide signalling and stress is an area of extreme clinical, pharmacological, toxicological, biochemical and chemical research interest. The utility of nitric oxide and derived species as signalling agents is due to their novel and vast chemical interactions with a variety of biological targets. Herein, the chemistry associated with the interaction of the biologically relevant nitrogen oxide species with fundamental biochemical targets is discussed. Specifically, the chemical interactions of nitrogen oxides with nucleophiles (e.g. thiols), metals (e.g. hemeproteins) and paramagnetic species (e.g. dioxygen and superoxide) are addressed. Importantly, the terms associated with the mechanisms by which NO (and derived species) react with their respective biological targets have been defined by numerous past chemical studies. Thus, in order to assist researchers in referring to chemical processes associated with nitrogen oxide biology, the vernacular associated with these chemical interactions is addressed. PMID:23617570

  13. Denitrifying SUP05 Require Exogenous Nitrogen

    NASA Astrophysics Data System (ADS)

    Shah, V.; Chang, B. X.; Morris, R. M.

    2016-02-01

    Members of the SUP05 clade of gamma-proteobacteria are among the most abundant chemoautotrophs in the ocean. Environmental sequencing studies suggest that they have critical roles in mediating carbon fixation, denitrification, and sulfur oxidation in oxygen minimum zones (OMZs). They have evaded cultivation and little is known about the specific growth requirements or substrate ranges that determine their abundance, distribution and impact on marine biogeochemical cycles. We evaluated the genetic potential of an isolate from the SUP05 clade "Ca. Thioglobus autotrophica strain EF1" to fix carbon, reduce nitrogen and oxidize sulfur under anaerobic growth conditions. Growth experiments support genomic predictions, indicating that strain EF1 is a facultatively anaerobic sulfur-oxidizing chemolithoautotroph that reduces nitrate to nitrite and nitric oxide to nitrous oxide. These experiments also revealed that strain EF1 is limited for growth by ammonium, which indicates that it requires an exogenous source of nitrogen for biosynthesis. Evidence that SUP05 cells produce nitrite and nitrous oxide and require exogenous nitrogen suggests that they have important roles in nitrogen cycling and that their growth is ultimately limited by the degradation of sinking organic matter.

  14. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2005-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  15. High Temperature Decomposition of Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2004-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydropemxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  16. 40 CFR 52.65 - Control Strategy: Nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control Strategy: Nitrogen oxides. 52.65 Section 52.65 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Alabama § 52.65 Control Strategy: Nitrogen...

  17. OXIDATION AND DEVOLATILIZATION OF NITROGEN IN COAL CHAR

    EPA Science Inventory

    The reactions of organically-bound nitrogen in coal char during combustion have been studied in a laboratory furnace using size-graded char particles prepared by the pyrolysis of a Montana lignite. The time-resolved variations of nitrogen-to-carbon ratio during char oxidation hav...

  18. [Anoxic bioremediation of urban polluted river water with biofilm].

    PubMed

    Zhang, Yong-Ming; Hu, Yi-Zhen; Yan, Rong; Liu, Fang

    2009-07-15

    Reactor like oxidation ditch was used for anaerobic bioremediation of urban river water, in which biofilm formed on ceramic honeycomb carrier was used instated of activated sludge. The dissolved oxygen in the wastewater was controlled under 0.5 mg/L for anoxic oxidation, and ammonia nitrogen was removed 40 to 60 percent, and total nitrogen removed 40 to 45 percent, that is ammonia nitrogen and total nitrogen were removed at the same time, also, nitrite was not any accumulated during the process. The biofilm was taken into flask to culture under anoxic oxidation condition in order to prove if anaerobic ammonium oxidation (ANAMMOX) occurred in the process, and ammonia and nitrite nitrogen were also removed at the same time in the experiment, which suggested that nitrification-denitrification and ANAMMOX occurred in bioremediation of urban surface water with low ratio of carbon and nitrogen at the same time. The anammox bacteria were existed in the biofilm according to molecular biological analysis. The experiment will be significant for bioremediation of eutrophication water body.

  19. An analytical study of nitrogen oxides and carbon monoxide emissions in hydrocarbon combustion with added nitrogen, preliminary results

    NASA Technical Reports Server (NTRS)

    Bittker, D. A.

    1979-01-01

    The effect of combustor operating conditions on the conversion of fuel-bound nitrogen (FBN) to nitrogen oxides NO sub x was analytically determined. The effect of FBN and of operating conditions on carbon monoxide (CO) formation was also studied. For these computations, the combustor was assumed to be a two stage, adiabatic, perfectly-stirred reactor. Propane-air was used as the combustible mixture and fuel-bound nitrogen was simulated by adding nitrogen atoms to the mixture. The oxidation of propane and formation of NO sub x and CO were modeled by a fifty-seven reaction chemical mechanism. The results for NO sub x and CO formation are given as functions of primary and secondary stage equivalence ratios and residence times.

  20. Spatial and temporal variability of nitrate and nitrous oxide concentrations in the unsaturated zone at a corn field in the US Midwest

    NASA Astrophysics Data System (ADS)

    Gopalakrishnan, G.; Negri, C.

    2011-12-01

    There has been a significant increase in reactive nitrogen in the environment as a result of human activity. Reactive nitrogen of anthropogenic origin now equals that derived from natural terrestrial nitrogen fixation and is expected to exceed it by the end of the decade. Nitrogen is applied to crops as fertilizer and impacts the environment through water quality impairments (mostly as nitrate) and as greenhouse gas emissions (as nitrous oxide). Research on environmental impacts resulting from nitrogen application in the form of fertilizers has focused disproportionately on the degradation of water quality from agricultural non-point sources. The impacts of this degradation are registered both locally, with runoff and percolation of agrochemicals into local surface water and groundwater, and on a larger scale, such as the increase in the anoxic zone in the Gulf of Mexico attributed to nitrate from the Mississippi River. Impacts to the global climate from increased production of nitrous oxide as a result of increased fertilization are equally significant. Nitrous oxide is a greenhouse gas with a warming potential that is approximately 300 times greater than carbon dioxide. Direct emissions of nitrous oxide from the soil have been expressed as 1% of the applied nitrogen. Indirect emissions due to runoff, leaching and volatilization of the nitrogen from the field have been expressed as 0.75% of the applied nitrogen. Many studies have focused on processes governing nitrogen fluxes in the soil, surface water and groundwater systems. However, research on the biogeochemical processes regulating nitrogen fluxes in the unsaturated zone and consequent impacts on nitrate and nitrous oxide concentrations in groundwater are lacking. Our study explores the spatial and temporal variability of nitrate and nitrous oxide concentrations in the vadose zone at a 15 acre corn field in the US Midwest and links it to the concentrations found in the groundwater at the field site. Results indicated that nitrate concentrations in the vadose zone were an order of magnitude greater than in the groundwater. Nitrous oxide concentrations were significantly less in the vadose zone, suggesting that conditions for microbial degradation of the nitrate were not optimal. There was significant short-term variability in the nitrate concentrations as well as spatial variability over the field site. While the processes governing the linkage between nitrogen concentrations in the unsaturated and saturated zones are still unclear, our research suggests that current models may overestimate the indirect emissions of nitrous oxide produced in agricultural systems.

  1. Effect of nitrogen addition on the structural, electrical, and optical properties of In-Sn-Zn oxide thin films

    NASA Astrophysics Data System (ADS)

    Jia, Junjun; Torigoshi, Yoshifumi; Suko, Ayaka; Nakamura, Shin-ichi; Kawashima, Emi; Utsuno, Futoshi; Shigesato, Yuzo

    2017-02-01

    Indium-tin-zinc oxide (ITZO) films were deposited at various nitrogen flow ratios using magnetron sputtering. At a nitrogen flow ratio of 40%, the structure of ITZO film changed from amorphous, with a short-range-ordered In2O3 phase, to a c-axis oriented InN polycrystalline phase, where InN starts to nucleate from an amorphous In2O3 matrix. Whereas, nitrogen addition had no obvious effect on the structure of indium-gallium-zinc oxide (IGZO) films even at a nitrogen flow ratio of 100%. Nitrogen addition also suppressed the formation of oxygen-related vacancies in ITZO films when the nitrogen flow ratio was less than 20%, and higher nitrogen addition led to an increase in carrier density. Moreover, a red-shift in the optical band edge was observed as the nitrogen flow ratio increased, which could be attributed to the generation of InN crystallites. We anticipate that the present findings demonstrating nitrogen-addition induced structural changes can help to understand the environment-dependent instability in amorphous IGZO or ITZO based thin-film transistors (TFTs).

  2. “Transference Ratios” to Predict Total Oxidized Sulfur and Nitrogen Deposition – Part I, Monitoring Results

    EPA Science Inventory

    Use of model-predicted “transference ratios” is currently under consideration by the US EPA in the formulation of a Secondary National Ambient Air Quality Standard for oxidized nitrogen and oxidized sulfur. This term is an empirical parameter defined for oxidized sulfur (TS)as th...

  3. 75 FR 48566 - Approval and Promulgation of Air Quality Implementation Plans; Delaware; Administrative and Non...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-11

    ...''; Regulation 12 ``Control of Nitrogen Oxide Emissions''; Regulation 1113* ``Open Burning''; Regulation 14... of General Federal Actions to the State Implementation Plans''; Regulation 39 ``Nitrogen Oxides (NO X..., Intergovernmental relations, Nitrogen dioxide, Ozone, Particulate matter, Reporting and recordkeeping requirements...

  4. Effect of feed-gas humidity on nitrogen atmospheric-pressure plasma jet for biological applications.

    PubMed

    Stephan, Karl D; McLean, Robert J C; DeLeon, Gian; Melnikov, Vadim

    2016-11-14

    We investigate the effect of feed-gas humidity on the oxidative properties of an atmospheric-pressure plasma jet using nitrogen gas. Plasma jets operating at atmospheric pressure are finding uses in medical and biological settings for sterilization and other applications involving oxidative stress applied to organisms. Most jets use noble gases, but some researchers use less expensive nitrogen gas. The feed-gas water content (humidity) has been found to influence the performance of noble-gas plasma jets, but has not yet been systematically investigated for jets using nitrogen gas. Low-humidity and high-humidity feed gases were used in a nitrogen plasma jet, and the oxidation effect of the jet was measured quantitatively using a chemical dosimeter known as FBX (ferrous sulfate-benzoic acid-xylenol orange). The plasma jet using high humidity was found to have about ten times the oxidation effect of the low-humidity jet, as measured by comparison with the addition of measured amounts of hydrogen peroxide to the FBX dosimeter. Atmospheric-pressure plasma jets using nitrogen as a feed gas have a greater oxidizing effect with a high level of humidity added to the feed gas.

  5. Evaluation of Toxic Effects of Aeration and Trichloroethylene Oxidation on Methanotrophic Bacteria Grown with Different Nitrogen Sources

    PubMed Central

    Chu, Kung-Hui; Alvarez-Cohen, Lisa

    1999-01-01

    In this study we evaluated specific and nonspecific toxic effects of aeration and trichloroethylene (TCE) oxidation on methanotrophic bacteria grown with different nitrogen sources (nitrate, ammonia, and molecular nitrogen). The specific toxic effects, exerted directly on soluble methane monooxygenase (sMMO), were evaluated by comparing changes in methane uptake rates and naphthalene oxidation rates following aeration and/or TCE oxidation. Nonspecific toxic effects, defined as general cellular damage, were examined by using a combination of epifluorescent cellular stains to measure viable cell numbers based on respiratory activity and measuring formate oxidation activities following aeration and TCE transformation. Our results suggest that aeration damages predominantly sMMO rather than other general cellular components, whereas TCE oxidation exerts a broad range of toxic effects that damage both specific and nonspecific cellular functions. TCE oxidation caused sMMO-catalyzed activity and respiratory activity to decrease linearly with the amount of substrate degraded. Severe TCE oxidation toxicity resulted in total cessation of the methane, naphthalene, and formate oxidation activities and a 95% decrease in the respiratory activity of methanotrophs. The failure of cells to recover even after 7 days of incubation with methane suggests that cellular recovery following severe TCE product toxicity is not always possible. Our evidence suggests that generation of greater amounts of sMMO per cell due to nitrogen fixation may be responsible for enhanced TCE oxidation activities of nitrogen-fixing methanotrophs rather than enzymatic protection mechanisms associated with the nitrogenase enzymes. PMID:9925614

  6. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2004-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO.sub.2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  7. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2011-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO.sub.2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  8. Decomposition of nitric oxide in a hot nitrogen stream to synthesize air for hypersonic wind tunnel combustion testing

    NASA Technical Reports Server (NTRS)

    Zumdieck, J. F.; Zlatarich, S. A.

    1974-01-01

    A clean source of high enthalpy air was obtained from the exothermic decomposition of nitric oxide in the presence of strongly heated nitrogen. A nitric oxide jet was introduced into a confined coaxial nitrogen stream. Measurements were made of the extent of mixing and reaction. Experimental results are compared with one- and two-dimensional chemical kinetics computations. Both analyses predict much lower reactivity than was observed experimentally. Inlet nitrogen temperatures above 2400 K were sufficient to produce experimentally a completely reacted gas stream of synthetic air.

  9. Nitrogen Oxide Fluxes and Nitrogen Cycling during Postagricultural Succession and Forest Fertilization in the Humid Tropics.

    Treesearch

    Heather Erickson; Michael Keller; Eric Davidson

    2001-01-01

    The effects of changes in tropical land use on soil emissions of nitrous oxide (N2O) and nitric oxide (NO) are not well understood. We examined emissions of N2O and NO and their relationships to land use and forest composition, litterfall, soil nitrogen (N) pools and turnover, soil moisture, and patterns of carbon (C) cycling in a lower montane, subtropical wet region...

  10. Kinetics of the formation of ozone and nitrogen oxides due to a pulsed microwave discharge in air

    NASA Astrophysics Data System (ADS)

    Larin, V. F.; Rumiantsev, S. A.

    1989-03-01

    The paper presents results of a numerical simulation of the kinetics of plasma-chemical processes induced by a single microwave pulse in the stratosphere. It is shown that the gas temperature is one of the main factors influencing the concentration ratio of ozone and nitrogen oxides formed under the effect of a microwave pulse. Long pulses, producing considerable gas heating, favor the formation of nitrogen oxides.

  11. Nitrogen and Oxygen Isotope Effects of Ammonia Oxidation by Thermophilic Thaumarchaeota from a Geothermal Water Stream

    PubMed Central

    Sakai, Sanae; Konno, Uta; Nakahara, Nozomi; Takaki, Yoshihiro; Saito, Yumi; Imachi, Hiroyuki; Tasumi, Eiji; Makabe, Akiko; Koba, Keisuke; Takai, Ken

    2016-01-01

    ABSTRACT Ammonia oxidation regulates the balance of reduced and oxidized nitrogen pools in nature. Although ammonia-oxidizing archaea have been recently recognized to often outnumber ammonia-oxidizing bacteria in various environments, the contribution of ammonia-oxidizing archaea is still uncertain due to difficulties in the in situ quantification of ammonia oxidation activity. Nitrogen and oxygen isotope ratios of nitrite (δ15NNO2− and δ18ONO2−, respectively) are geochemical tracers for evaluating the sources and the in situ rate of nitrite turnover determined from the activities of nitrification and denitrification; however, the isotope ratios of nitrite from archaeal ammonia oxidation have been characterized only for a few marine species. We first report the isotope effects of ammonia oxidation at 70°C by thermophilic Thaumarchaeota populations composed almost entirely of “Candidatus Nitrosocaldus.” The nitrogen isotope effect of ammonia oxidation varied with ambient pH (25‰ to 32‰) and strongly suggests the oxidation of ammonia, not ammonium. The δ18O value of nitrite produced from ammonia oxidation varied with the δ18O value of water in the medium but was lower than the isotopic equilibrium value in water. Because experiments have shown that the half-life of abiotic oxygen isotope exchange between nitrite and water is longer than 33 h at 70°C and pH ≥6.6, the rate of ammonia oxidation by thermophilic Thaumarchaeota could be estimated using δ18ONO2− in geothermal environments, where the biological nitrite turnover is likely faster than 33 h. This study extended the range of application of nitrite isotopes as a geochemical clock of the ammonia oxidation activity to high-temperature environments. IMPORTANCE Because ammonia oxidation is generally the rate-limiting step in nitrification that regulates the balance of reduced and oxidized nitrogen pools in nature, it is important to understand the biological and environmental factors underlying the regulation of the rate of ammonia oxidation. The discovery of ammonia-oxidizing archaea (AOA) in marine and terrestrial environments has transformed the concept that ammonia oxidation is operated only by bacterial species, suggesting that AOA play a significant role in the global nitrogen cycle. However, the archaeal contribution to ammonia oxidation in the global biosphere is not yet completely understood. This study successfully identified key factors controlling nitrogen and oxygen isotopic ratios of nitrite produced from thermophilic Thaumarchaeota and elucidated the applicability and its limit of nitrite isotopes as a geochemical clock of ammonia oxidation rate in nature. Oxygen isotope analysis in this study also provided new biochemical information on archaeal ammonia oxidation. PMID:27208107

  12. Nitrogen and Oxygen Isotope Effects of Ammonia Oxidation by Thermophilic Thaumarchaeota from a Geothermal Water Stream.

    PubMed

    Nishizawa, Manabu; Sakai, Sanae; Konno, Uta; Nakahara, Nozomi; Takaki, Yoshihiro; Saito, Yumi; Imachi, Hiroyuki; Tasumi, Eiji; Makabe, Akiko; Koba, Keisuke; Takai, Ken

    2016-08-01

    Ammonia oxidation regulates the balance of reduced and oxidized nitrogen pools in nature. Although ammonia-oxidizing archaea have been recently recognized to often outnumber ammonia-oxidizing bacteria in various environments, the contribution of ammonia-oxidizing archaea is still uncertain due to difficulties in the in situ quantification of ammonia oxidation activity. Nitrogen and oxygen isotope ratios of nitrite (δ(15)NNO2- and δ(18)ONO2-, respectively) are geochemical tracers for evaluating the sources and the in situ rate of nitrite turnover determined from the activities of nitrification and denitrification; however, the isotope ratios of nitrite from archaeal ammonia oxidation have been characterized only for a few marine species. We first report the isotope effects of ammonia oxidation at 70°C by thermophilic Thaumarchaeota populations composed almost entirely of "Candidatus Nitrosocaldus." The nitrogen isotope effect of ammonia oxidation varied with ambient pH (25‰ to 32‰) and strongly suggests the oxidation of ammonia, not ammonium. The δ(18)O value of nitrite produced from ammonia oxidation varied with the δ(18)O value of water in the medium but was lower than the isotopic equilibrium value in water. Because experiments have shown that the half-life of abiotic oxygen isotope exchange between nitrite and water is longer than 33 h at 70°C and pH ≥6.6, the rate of ammonia oxidation by thermophilic Thaumarchaeota could be estimated using δ(18)ONO2- in geothermal environments, where the biological nitrite turnover is likely faster than 33 h. This study extended the range of application of nitrite isotopes as a geochemical clock of the ammonia oxidation activity to high-temperature environments. Because ammonia oxidation is generally the rate-limiting step in nitrification that regulates the balance of reduced and oxidized nitrogen pools in nature, it is important to understand the biological and environmental factors underlying the regulation of the rate of ammonia oxidation. The discovery of ammonia-oxidizing archaea (AOA) in marine and terrestrial environments has transformed the concept that ammonia oxidation is operated only by bacterial species, suggesting that AOA play a significant role in the global nitrogen cycle. However, the archaeal contribution to ammonia oxidation in the global biosphere is not yet completely understood. This study successfully identified key factors controlling nitrogen and oxygen isotopic ratios of nitrite produced from thermophilic Thaumarchaeota and elucidated the applicability and its limit of nitrite isotopes as a geochemical clock of ammonia oxidation rate in nature. Oxygen isotope analysis in this study also provided new biochemical information on archaeal ammonia oxidation. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  13. 40 CFR 52.326 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Area-wide nitrogen oxides (NOX) exemptions. 52.326 Section 52.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.326 Area-wide nitrogen...

  14. 40 CFR 52.326 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Area-wide nitrogen oxides (NOX) exemptions. 52.326 Section 52.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.326 Area-wide nitrogen...

  15. 40 CFR 52.326 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Area-wide nitrogen oxides (NOX) exemptions. 52.326 Section 52.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.326 Area-wide nitrogen...

  16. 40 CFR 52.326 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Area-wide nitrogen oxides (NOX) exemptions. 52.326 Section 52.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.326 Area-wide nitrogen...

  17. 40 CFR 52.326 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Area-wide nitrogen oxides (NOX) exemptions. 52.326 Section 52.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.326 Area-wide nitrogen...

  18. TECHNOLOGY INNOVATIONS AND EXPERIENCE CURVES FOR NITROGEN OXIDES CONTROL TECHNOLOGIES

    EPA Science Inventory

    This paper reviews the regulatory history for nitrogen oxides (NOX) pollutant emissions from stationary sources, primarily in coal-fired power plants. Nitrogen dioxide (NO2) is one of the six criteria pollutants regulated by the 1970 Clean Air Act where Nati...

  19. 40 CFR 86.223-94 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Oxides of nitrogen analyzer calibration. 86.223-94 Section 86.223-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... nitrogen analyzer calibration. The provisions of § 86.123-78 apply to this subpart if NOX measurements are...

  20. 40 CFR 86.223-94 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Oxides of nitrogen analyzer calibration. 86.223-94 Section 86.223-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... nitrogen analyzer calibration. The provisions of § 86.123-78 apply to this subpart if NOX measurements are...

  1. 40 CFR 86.223-94 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Oxides of nitrogen analyzer calibration. 86.223-94 Section 86.223-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... nitrogen analyzer calibration. The provisions of § 86.123-78 apply to this subpart if NOX measurements are...

  2. 75 FR 31711 - Approval and Promulgation of Air Quality Implementation Plans; Delaware; Control of Nitrogen...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-04

    ... Boilers and Process Heaters at Petroleum Refineries AGENCY: Environmental Protection Agency (EPA). ACTION... controlling nitrogen oxide (NOx) emissions from industrial boilers. This action is being taken under the Clean...--Control of Nitrogen Oxide Emissions from Industrial Boilers and Process Heaters at Petroleum Refineries in...

  3. Draft Plan for Development of the Integrated Science Assessment for Nitrogen Oxides - Health Criteria

    EPA Science Inventory

    EPA has announced a draft development plan for the next Integrated Science Assessment (ISA) for the health effects of nitrogen oxides (NOX) which will serve as the scientific basis for review of the primary (health-based) National Ambient Air Quality Standard for nitrogen dioxide...

  4. Experimental study and kinetic modeling of hydrogen and carbon monoxide oxidation perturbed by nitrogen and sulfur oxides

    NASA Astrophysics Data System (ADS)

    Mueller, Mark Anthony

    2000-10-01

    Increasingly stringent regulations have and will likely continue to place considerable constraints on combustion-generated pollutants, including carbon monoxide, nitrogen oxides, and sulfur oxides. The speciation of these pollutants and, by extension, their impact, is likely affected by kinetic interactions that occur during post-combustion processes. To gain a fundamental understanding of these interactions, the oxidation of hydrogen and carbon monoxide in the presence of trace quantities of NO, NO2, and SO2 was experimentally and numerically studied at conditions relevant to modern internal combustion engines. Experimental data were obtained using a well-characterized flow reactor over pressure and temperature ranges of 0.4--14.0 atm and 750--1040 K, respectively, using dilute (˜1% fuel) H2/O2 and CO/H2O/O2 mixtures perturbed with ppm quantities of NO, NO2, and/or SO2. The overall effects of these species were found to be highly sensitive to pressure, temperature, and equivalence ratio. In general, small quantities of NO promoted fuel consumption by converting HO2 radicals to highly reactive OH radicals, while high concentrations of NO and/or NO2 were inhibiting due to the catalysis of radical recombination reactions. In the absence of NO, SO2 strongly inhibited CO oxidation, but the simultaneous presence of NO and SO2 yielded synergistic effects that significantly reduced the inhibition from SO 2. Over the range of conditions explored, direct interactions between NOx and SOx species did rot appear to significantly influence the relative NO and NO2 concentrations; however, the reaction between NO2 and SO2 may be an important source of SO3 in certain circumstances. A detailed reaction mechanism. has been developed in a hierarchical manner, beginning with the H2/O2 and CO/H2O/O 2 systems and sequentially adding reactions necessary to describe the perturbing effects of NOx and SOx species. The experimental data were used in conjunction with gradient sensitivity and reaction flux analyses to determine key reaction pathways and to derive rate data for the H+O2(+M)=HO2(+M), H2+NO2=HONO+H, and SO2+O(+M) SO3(+M) reactions. Modifications to the rate constants for these and other reactions are discussed in relation to the mechanism's predictive ability with respect to the H2/O 2, CO/H2O/O2, H2/NO2, H 2/O2/NOx, and CO/H2O/O2/NO x/SOx systems over a wide range of conditions.

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

    PubMed

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

    2015-09-01

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

  6. Process for Nitrogen Oxide Waste Conversion to Fertilizer

    NASA Technical Reports Server (NTRS)

    Lueck, Dale E. (Inventor); Parrish, Clyde F. (Inventor)

    2003-01-01

    The present invention describes a process for converting vapor streams from sources containing at least one nitrogen-containing oxidizing agent therein to a liquid fertilizer composition comprising the steps of: a) directing a vapor stream containing at least one nitrogen-containing oxidizing agent to a first contact zone; b) contacting said vapor stream with water to form nitrogen oxide(s) from said at least one nitrogen-containing oxidizing agent; c) directing said acid(s) as a second stream to a second contact zone; d) exposing said second stream to hydrogen peroxide which is present within said second contact zone in a relative amount of at least 0.1% by weight of said second stream within said second contact zone to convert at least some of any nitrogen oxide species or ions other than in the nitrate form present within said second stream to nitrate ion; e) sampling said stream within said second contact zone to determine the relative amount of hydrogen peroxide within said second contact zone; f) adding hydrogen peroxide to said second contact zone when a level of hydrogen peroxide less than 0.1 % by weight in said second stream is determined by said sampling; g) adding a solution comprising potassium hydroxide to said second stream to maintain a pH between 6.0 and 11.0 within said second stream within said second contact zone to form a solution of potassium nitrate; and h) removing said solution of potassium nitrate from said second contact zone.

  7. Process and Equipment for Nitrogen Oxide Waste Conversion to Fertilizer

    NASA Technical Reports Server (NTRS)

    Lueck, Dale E. (Inventor); Parrish, Clyde F. (Inventor)

    2000-01-01

    The present invention describes a process for converting vapor streams from sources containing at least one nitrogen-containing oxidizing agent therein to a liquid fertilizer composition comprising the steps of: (1) directing a vapor stream containing at least nitrogen-containing oxidizing agent to a first contact zone; (2) contacting said vapor stream with water to form nitrogen oxide(s) from said at least one nitrogen- containing oxidizing agent; (3) directing said acid(s) as a second stream to a second contact zone; (4) exposing said second stream to hydrogen peroxide which is present within said second contact zone in a relative amount of at least 0.1% by weight of said second stream within said second contact zone to convert at least some of any nitrogen oxide species or ions other than in the nitrite form present within said second stream to nitrate ion; (5) sampling said stream within said second contact zone to determine the relative amount of hydrogen peroxide within said second contact zone; (6) adding hydrogen peroxide to said second contact zone when a level on hydrogen peroxide less than 0.1% by weight in said second stream is determined by said sampling; (7) adding a solution comprising potassium hydroxide to said second stream to maintain a pH between 6.0 and 11.0 within said second stream within said second contact zone to form a solution of potassium nitrate; and (8) removing sais solution of potassium nitrate from said second contact zone.

  8. A series of inorganic solid nitrogen sources for the synthesis of metal nitride clusterfullerenes: the dependence of production yield on the oxidation state of nitrogen and counter ion.

    PubMed

    Liu, Fupin; Guan, Jian; Wei, Tao; Wang, Song; Jiao, Mingzhi; Yang, Shangfeng

    2013-04-01

    A series of nitrogen-containing inorganic solid compounds with variable oxidation states of nitrogen and counter ions have been successfully applied as new inorganic solid nitrogen sources toward the synthesis of Sc-based metal nitride clusterfullerenes (Sc-NCFs), including ammonium salts [(NH4)xH(3-x)PO4 (x = 0-2), (NH4)2SO4, (NH4)2CO3, NH4X (X = F, Cl), NH4SCN], thiocyanate (KSCN), nitrates (Cu(NO3)2, NaNO3), and nitrite (NaNO2). Among them, ammonium phosphates ((NH4)xH(3-x)PO4, x = 1-3) and ammonium thiocyanate (NH4SCN) are revealed to behave as better nitrogen sources than others, and the highest yield of Sc-NCFs is achieved when NH4SCN was used as a nitrogen source. The optimum molar ratio of Sc2O3:(NH4)3PO4·3H2O:C and Sc2O3:NH4SCN:C has been determined to be 1:2:15 and 1:3:15, respectively. The thermal decomposition products of these 12 inorganic compounds have been discussed in order to understand their different performances toward the synthesis of Sc-NCFs, and accordingly the dependence of the production yield of Sc-NCFs on the oxidation state of nitrogen and counter ion is interpreted. The yield of Sc3N@C80 (I(h) + D(5h)) per gram Sc2O3 by using the N2-based group of nitrogen sources (thiocyanate, nitrates, and nitrite) is overall much lower than those by using gaseous N2 and NH4SCN, indicating the strong dependence of the yield of Sc-NCFs on the oxidation state of nitrogen, which is attributed to the "in-situ" redox reaction taking place for the N2-based group of nitrogen sources during discharging. For NH3-based group of nitrogen sources (ammonium salts) which exhibits a (-3) oxidation states of nitrogen, their performance as nitrogen sources is found to be sensitively dependent on the anion, and this is understood by considering their difference on the thermal stability and/or decomposition rate. Contrarily, for the N2-based group of nitrogen sources, the formation of Sc-NCFs is independent to both the oxidation state of nitrogen (+3 or +5) and the cation.

  9. Electrochemical process for the preparation of nitrogen fertilizers

    DOEpatents

    Aulich, Ted R [Grand Forks, ND; Olson, Edwin S [Grand Forks, ND; Jiang, Junhua [Grand Forks, ND

    2012-04-10

    The present invention provides methods and apparatus for the preparation of nitrogen fertilizers including ammonium nitrate, urea, urea-ammonium nitrate, and/or ammonia, at low temperature and pressure, preferably at ambient temperature and pressure, utilizing a source of carbon, a source of nitrogen, and/or a source of hydrogen or hydrogen equivalent. Implementing an electrolyte serving as ionic charge carrier, (1) ammonium nitrate is produced via the reduction of a nitrogen source at the cathode and the oxidation of a nitrogen source at the anode; (2) urea or its isomers are produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source; (3) ammonia is produced via the reduction of nitrogen source at the cathode and the oxidation of a hydrogen source or a hydrogen equivalent such as carbon monoxide or a mixture of carbon monoxide and hydrogen at the anode; and (4) urea-ammonium nitrate is produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source, and anodic oxidation of a nitrogen source. The electrolyte can be aqueous, non-aqueous, or solid.

  10. Review of the Secondary National Ambient Air Quality Standard for Nitrogen Oxides, Sulfur Oxides and Particulate Matter: Risk and Exposure Assessment Planning Document

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) is conducting a review of the air quality criteria and the secondary (welfare-based) national ambient air quality standards (NAAQS) for nitrogen oxides (NOx), sulfur oxides (SOx), and particulate matter (PM). The major phases of the ...

  11. A Continuous Flow System for the Measurement of Ambient Nitrogen Oxides [NO + NO2] Using Rhodamine B Hydrazide as a Chemosensor.

    PubMed

    Malingappa, Pandurangappa; Yarradoddappa, Venkataramanappa

    2014-01-01

    A new chemosensor has been used to monitor atmospheric nitrogen oxides [NO + NO2] at parts per billion (ppb) level. It is based on the catalytic reaction of nitrogen oxides with rhodamine B hydrazide (RBH) to produce a colored compound through the hydrolysis of the amide bond of the molecule. A simple colorimeter has been used to monitor atmospheric nitrogen dioxide at ppb level. The air samples were purged through a sampling cuvette containing RBH solution using peristaltic pump. The proposed method has been successfully applied to monitor the ambient nitrogen dioxide levels at traffic junction points within the city limits and the results obtained are compared with the standard Griess-Ilosvay method.

  12. SO x /NO x Removal from Flue Gas Streams by Solid Adsorbents: A Review of Current Challenges and Future Directions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rezaei, Fateme; Rownaghi, Ali A.; Monjezi, Saman

    One of the main challenges in the power and chemical industries is to remove generated toxic or environmentally harmful gases before atmospheric emission. To comply with stringent environmental and pollutant emissions control regulations, coal-fired power plants must be equipped with new technologies that are efficient and less energy-intensive than status quo technologies for flue gas cleanup. While conventional sulfur oxide (SOx) and nitrogen oxide (NOx) removal technologies benefit from their large-scale implementation and maturity, they are quite energy-intensive. In view of this, the development of lower-cost, less energy-intensive technologies could offer an advantage. Significant energy and cost savings can potentiallymore » be realized by using advanced adsorbent materials. One of the major barriers to the development of such technologies remains the development of materials that are efficient and productive in removing flue gas contaminants. In this review, adsorption-based removal of SOx/NOx impurities from flue gas is discussed, with a focus on important attributes of the solid adsorbent materials as well as implementation of the materials in conventional and emerging acid gas removal technologies. The requirements for effective adsorbents are noted with respect to their performance, key limitations, and suggested future research directions. The final section includes some key areas for future research and provides a possible roadmap for the development of technologies for the removal of flue gas impurities that are more efficient and cost-effective than status quo approaches.« less

  13. Reactive nitrogen oxides in the southeast United States national parks: source identification, origin, and process budget

    NASA Astrophysics Data System (ADS)

    Tong, Daniel Quansong; Kang, Daiwen; Aneja, Viney P.; Ray, John D.

    2005-01-01

    We present in this study both measurement-based and modeling analyses for elucidation of source attribution, influence areas, and process budget of reactive nitrogen oxides at two rural southeast United States sites (Great Smoky Mountains national park (GRSM) and Mammoth Cave national park (MACA)). Availability of nitrogen oxides is considered as the limiting factor to ozone production in these areas and the relative source contribution of reactive nitrogen oxides from point or mobile sources is important in understanding why these areas have high ozone. Using two independent observation-based techniques, multiple linear regression analysis and emission inventory analysis, we demonstrate that point sources contribute a minimum of 23% of total NOy at GRSM and 27% at MACA. The influence areas for these two sites, or origins of nitrogen oxides, are investigated using trajectory-cluster analysis. The result shows that air masses from the West and Southwest sweep over GRSM most frequently, while pollutants transported from the eastern half (i.e., East, Northeast, and Southeast) have limited influence (<10% out of all air masses) on air quality at GRSM. The processes responsible for formation and removal of reactive nitrogen oxides are investigated using a comprehensive 3-D air quality model (Multiscale Air Quality SImulation Platform (MAQSIP)). The NOy contribution associated with chemical transformations to NOz and O3, based on process budget analysis, is as follows: 32% and 84% for NOz, and 26% and 80% for O3 at GRSM and MACA, respectively. The similarity between NOz and O3 process budgets suggests a close association between nitrogen oxides and effective O3 production at these rural locations.

  14. Thermal NF3 fluorination/oxidation of cobalt, yttrium, zirconium, and selected lanthanide oxides

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Scheele, Randall D.; McNamara, Bruce K.; Casella, Andrew M.

    2013-02-01

    This paper presents results of our continuing investigation on the use of nitrogen trifluoride as a fluorination or fluorination/oxidation agent for separating valuable constituents from used nuclear fuels by exploiting the different volatilities of the constituent fission product and actinide fluorides. This article focuses on fission products that do not have volatile fluorides or oxyfluorides at expected operations temperatures. Our thermodynamic calculations show that nitrogen trifluoride has the potential to completely fluorinate fission product oxides to their fluorides. Simultaneous thermogravimetric and differential thermal analyses show that the oxides of cobalt, zirconium, and the lanthanides are fluorinated but do not formmore » volatile fluorides when treated with nitrogen trifluoride at temperatures up to 550°C. Our studies of gadolinium-doped commercial nuclear fuel indicate that nitrogen trifluoride can extract uranium from the non-volatile gadolinium.« less

  15. [Ammonia-oxidizing archaea and their important roles in nitrogen biogeochemical cycling: a review].

    PubMed

    Liu, Jing-Jing; Wu, Wei-Xiang; Ding, Ying; Shi, De-Zhi; Chen, Ying-Xu

    2010-08-01

    As the first step of nitrification, ammonia oxidation is the key process in global nitrogen biogeochemical cycling. So far, the autotrophic ammonia-oxidizing bacteria (AOB) in the beta- and gamma-subgroups of proteobacteria have been considered as the most important contributors to ammonia oxidation, but the recent researches indicated that ammonia-oxidizing archaea (AOA) are widely distributed in various kinds of ecosystems and quantitatively predominant, playing important roles in the global nitrogen biogeochemical cycling. This paper reviewed the morphological, physiological, and ecological characteristics and the molecular phylogenies of AOA, and compared and analyzed the differences and similarities of the ammonia monooxygenase (AMO) and its encoding genes between AOA and AOB. In addition, the potential significant roles of AOA in nitrogen biogeochemical cycling in aquatic and terrestrial ecosystems were summarized, and the future research directions of AOA in applied ecology and environmental protection were put forward.

  16. Lightning NOx and Impacts on Air Quality

    NASA Technical Reports Server (NTRS)

    Murray, Lee T.

    2016-01-01

    Lightning generates relatively large but uncertain quantities of nitrogen oxides, critical precursors for ozone and hydroxyl radical (OH), the primary tropospheric oxidants. Lightning nitrogen oxide strongly influences background ozone and OH due to high ozone production efficiencies in the free troposphere, effecting small but non-negligible contributions to surface pollutant concentrations. Lightning globally contributes 3-4 ppbv of simulated annual-mean policy-relevant background (PRB) surface ozone, comprised of local, regional, and hemispheric components, and up to 18 ppbv during individual events. Feedbacks via methane may counter some of these effects on decadal time scales. Lightning contributes approximately 1 percent to annual-mean surface particulate matter, as a direct precursor and by promoting faster oxidation of other precursors. Lightning also ignites wildfires and contributes to nitrogen deposition. Urban pollution influences lightning itself, with implications for regional lightning-nitrogen oxide production and feedbacks on downwind surface pollution. How lightning emissions will change in a warming world remains uncertain.

  17. Nitrous oxide production by lithotrophic ammonia-oxidizing bacteria and implications for engineered nitrogen-removal systems.

    PubMed

    Chandran, Kartik; Stein, Lisa Y; Klotz, Martin G; van Loosdrecht, Mark C M

    2011-12-01

    Chemolithoautotrophic AOB (ammonia-oxidizing bacteria) form a crucial component in microbial nitrogen cycling in both natural and engineered systems. Under specific conditions, including transitions from anoxic to oxic conditions and/or excessive ammonia loading, and the presence of high nitrite (NO₂⁻) concentrations, these bacteria are also documented to produce nitric oxide (NO) and nitrous oxide (N₂O) gases. Essentially, ammonia oxidation in the presence of non-limiting substrate concentrations (ammonia and O₂) is associated with N₂O production. An exceptional scenario that leads to such conditions is the periodical switch between anoxic and oxic conditions, which is rather common in engineered nitrogen-removal systems. In particular, the recovery from, rather than imposition of, anoxic conditions has been demonstrated to result in N₂O production. However, applied engineering perspectives, so far, have largely ignored the contribution of nitrification to N₂O emissions in greenhouse gas inventories from wastewater-treatment plants. Recent field-scale measurements have revealed that nitrification-related N₂O emissions are generally far higher than emissions assigned to heterotrophic denitrification. In the present paper, the metabolic pathways, which could potentially contribute to NO and N₂O production by AOB have been conceptually reconstructed under conditions especially relevant to engineered nitrogen-removal systems. Taken together, the reconstructed pathways, field- and laboratory-scale results suggest that engineering designs that achieve low effluent aqueous nitrogen concentrations also minimize gaseous nitrogen emissions.

  18. PM, NOx and butane emissions from on-road vehicle fleets in Hong Kong and their implications on emission control policy

    NASA Astrophysics Data System (ADS)

    Ning, Zhi; Wubulihairen, Maimaitireyimu; Yang, Fenhuan

    2012-12-01

    Vehicular emissions are the major sources of air pollution in urban areas. For metropolitan cities with large population working and living in environments with direct traffic impact, emission control is of great significance to protect public health. Implementation of more stringent emission standards, retrofitting fleet with emission control devices and switching to clearer fuel has been commonly practiced in different cities including Hong Kong. The present study employed a new plume chasing method for effective and quick evaluation of on-road fleet emission factors of particulate matter (PM), nitrogen oxides (NOx), and butane from heavy duty diesel trucks, diesel buses and liquefied petroleum gas (LPG) vehicles. The results showed distinct profiles of the emissions from different fleets with excessive butane emissions from LPG fleet and contrasting PM and NOx emissions from diesel trucks and buses fleets. A cross comparison was also made with emission data from other cities and from historic local studies. The implications of the observed difference on the effectiveness of emission control measures and policy are discussed with recommendations of direction for future research and policy making.

  19. Liquid Phase Plasma Synthesis of Iron Oxide Nanoparticles on Nitrogen-Doped Activated Carbon Resulting in Nanocomposite for Supercapacitor Applications.

    PubMed

    Lee, Heon; Lee, Won-June; Park, Young-Kwon; Ki, Seo Jin; Kim, Byung-Joo; Jung, Sang-Chul

    2018-03-25

    Iron oxide nanoparticles supported on nitrogen-doped activated carbon powder were synthesized using an innovative plasma-in-liquid method, called the liquid phase plasma (LPP) method. Nitrogen-doped carbon (NC) was prepared by a primary LPP reaction using an ammonium chloride reactant solution, and an iron oxide/NC composite (IONCC) was prepared by a secondary LPP reaction using an iron chloride reactant solution. The nitrogen component at 3.77 at. % formed uniformly over the activated carbon (AC) surface after a 1 h LPP reaction. Iron oxide nanoparticles, 40~100 nm in size, were impregnated homogeneously over the NC surface after the LPP reaction, and were identified as Fe₃O₄ by X-ray photoelectron spectroscopy and X-ray diffraction. NC and IONCCs exhibited pseudo-capacitive characteristics, and their specific capacitance and cycling stability were superior to those of bare AC. The nitrogen content on the NC surface increased the compatibility and charge transfer rate, and the composites containing iron oxide exhibited a lower equivalent series resistance.

  20. Relationship between peroxyacetyl nitrate and nitrogen oxides in the clean troposphere

    NASA Technical Reports Server (NTRS)

    Singh, H. B.; Salas, L. J.; Ridley, B. A.; Shetter, J. D.; Donahue, N. M.

    1985-01-01

    The first study is presented in which the mixing ratios of peroxyactyl nitrate (PAN) and nitrogen oxides, as well as those of peroxypropionyl nitrate and O3 and relevant meteorological parameters, were measured concurrently at a location that receives clean, continental air. The results show that, in clean conditions, nitrogen oxides present in the form of PAN can be as much or more abundant than the inorganic form. In addition, PAN can be an important source of peroxyacetyl radicals which may be important to oxidation processes in the gas as well as liquid phases.

  1. Wet Oxidation as a Waste Treatment Method in Closed Systems

    NASA Technical Reports Server (NTRS)

    Onisko, B. L.; Wydeven, T.

    1982-01-01

    The chemistry of the wet oxidation process was investigated in relation to production of plant nutrients from plant and human waste materials as required for a closed life support system. Hydroponically grown lettuce plants were used as a model plant waste, and oxygen gas was used as an oxidant. Organic nitrogen content was decreased 88-100%, depending on feed material. Production of ammonia and nitrogen gas accounted for all of the observed decrease in organic nitrogen content. No nitrous oxide (N2O) was detected. The implications of these results for closed life support systems are discussed.

  2. Wet oxidation as a waste treatment in closed systems

    NASA Technical Reports Server (NTRS)

    Onisko, B. L.; Wydeven, T.

    1981-01-01

    The chemistry of the wet oxidation process has been investigated in relation to production of plant nutrients from plant and human waste materials as required for a closed life-support system. Hydroponically grown lettuce plants were used as a model plant waste and oxygen gas was used as oxidant. Organic nitrogen content was decreased 88-100% depending on feed material. Production of ammonia and nitrogen gas account for all of the observed decrease in organic nitrogen content. No nitrous oxide (N2O) was detected. The implications of these results for closed life-support systems are discussed.

  3. Niche differentiation in nitrogen metabolism among methanotrophs within an operational taxonomic unit

    PubMed Central

    2014-01-01

    Background The currently accepted thesis on nitrogenous fertilizer additions on methane oxidation activity assumes niche partitioning among methanotrophic species, with activity responses to changes in nitrogen content being dependent on the in situ methanotrophic community structure Unfortunately, widely applied tools for microbial community assessment only have a limited phylogenetic resolution mostly restricted to genus level diversity, and not to species level as often mistakenly assumed. As a consequence, intragenus or intraspecies metabolic versatility in nitrogen metabolism was never evaluated nor considered among methanotrophic bacteria as a source of differential responses of methane oxidation to nitrogen amendments. Results We demonstrated that fourteen genotypically different Methylomonas strains, thus distinct below the level at which most techniques assign operational taxonomic units (OTU), show a versatile physiology in their nitrogen metabolism. Differential responses, even among strains with identical 16S rRNA or pmoA gene sequences, were observed for production of nitrite and nitrous oxide from nitrate or ammonium, nitrogen fixation and tolerance to high levels of ammonium, nitrate, and hydroxylamine. Overall, reduction of nitrate to nitrite, nitrogen fixation, higher tolerance to ammonium than nitrate and tolerance and assimilation of nitrite were general features. Conclusions Differential responses among closely related methanotrophic strains to overcome inhibition and toxicity from high nitrogen loads and assimilation of various nitrogen sources yield competitive fitness advantages to individual methane-oxidizing bacteria. Our observations proved that community structure at the deepest phylogenetic resolution potentially influences in situ functioning. PMID:24708438

  4. Niche differentiation in nitrogen metabolism among methanotrophs within an operational taxonomic unit.

    PubMed

    Hoefman, Sven; van der Ha, David; Boon, Nico; Vandamme, Peter; De Vos, Paul; Heylen, Kim

    2014-04-04

    The currently accepted thesis on nitrogenous fertilizer additions on methane oxidation activity assumes niche partitioning among methanotrophic species, with activity responses to changes in nitrogen content being dependent on the in situ methanotrophic community structure Unfortunately, widely applied tools for microbial community assessment only have a limited phylogenetic resolution mostly restricted to genus level diversity, and not to species level as often mistakenly assumed. As a consequence, intragenus or intraspecies metabolic versatility in nitrogen metabolism was never evaluated nor considered among methanotrophic bacteria as a source of differential responses of methane oxidation to nitrogen amendments. We demonstrated that fourteen genotypically different Methylomonas strains, thus distinct below the level at which most techniques assign operational taxonomic units (OTU), show a versatile physiology in their nitrogen metabolism. Differential responses, even among strains with identical 16S rRNA or pmoA gene sequences, were observed for production of nitrite and nitrous oxide from nitrate or ammonium, nitrogen fixation and tolerance to high levels of ammonium, nitrate, and hydroxylamine. Overall, reduction of nitrate to nitrite, nitrogen fixation, higher tolerance to ammonium than nitrate and tolerance and assimilation of nitrite were general features. Differential responses among closely related methanotrophic strains to overcome inhibition and toxicity from high nitrogen loads and assimilation of various nitrogen sources yield competitive fitness advantages to individual methane-oxidizing bacteria. Our observations proved that community structure at the deepest phylogenetic resolution potentially influences in situ functioning.

  5. Ambient Ammonium Contribution to total Nitrogen Deposition ...

    EPA Pesticide Factsheets

    There has been a wealth of evidence over the last decade illustrating the rising importance of reduced inorganic nitrogen (NHx = ammonia gas, NH3, plus particulate ammonium, p-NH4) in the overall atmospheric mass balance and deposition of nitrogen as emissions of oxidized nitrogen have decreased throughout a period of stable or increasing NH3 emissions. In addition, the fraction of ambient ammonia relative to p-NH4 generally has risen as a result of decreases in both oxides of nitrogen and sulfur emissions. EPA plans to consider ecological effects related to deposition of nitrogen, of which NHx is a contributing component, in the review of secondary National Ambient Air Quality Standards (NAAQS) for oxides of nitrogen and sulfur (NOx/SOx standard). Although these ecological effects are associated with total nitrogen deposition, it will be important to understand the emissions sources contributing to the total nitrogen deposition and to understand how much of the total nitrogen deposition is from deposition of NHx versus other nitrogen species. Because p-NH4 contributes to nitrogen deposition and can also be a significant component of particulate matter, there is a potential overlap in addressing nitrogen based deposition effects in the secondary PM and NOx/SOx NAAQS. Consequently, there is a policy interest in quantifying the contribution of p-NH4 to total nitrogen deposition. While dry deposition of p-NH4 is calculated through a variety of modeling app

  6. Exterior view of north wall of LongTerm Oxidizer Silo (T28B) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Exterior view of north wall of Long-Term Oxidizer Silo (T-28B) and Oxidizer Conditioning Structure (T-28D) behind and to its immediate left, looking south. A nitrogen line, used to prepare the Titan II's nitrogen-tetroxide oxidizer, is in the right foreground - Air Force Plant PJKS, Systems Integration Laboratory, Long-Term Oxidizer Silo, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

  7. Impacts of Human Alteration of the Nitrogen Cycle in the U.S. on Radiative Forcing

    EPA Science Inventory

    Nitrogen cycling processes affect radiative forcing directly through emissions of nitrous oxide (N2O) and indirectly because emissions of nitrogen oxide (NO x ) and ammonia (NH3) affect atmospheric concentrations of methane (CH4), carbon dioxide (CO2), water vapor (H2O), ozone (O...

  8. 76 FR 52283 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Control of Nitrogen...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-22

    ... Promulgation of Air Quality Implementation Plans; Pennsylvania; Control of Nitrogen Oxides Emissions From Glass... revisions pertain to the control of nitrogen oxide (NO X ) emissions from glass melting furnaces. EPA is approving these revisions to reduce NO X emissions from glass melting furnaces in accordance with the...

  9. NO news is no new news

    USGS Publications Warehouse

    Fotheringham, C.J.; Keeley, J.E.

    2005-01-01

    In the paper 'NO News', Preston et al. (2004) make a number of erroneous assumptions regarding nitrogen oxide chemistry. These authors also present some very significant misinterpretations of previous research into the effects of various nitrogen oxides on germination of post-fire followers. Methodological differences between the study by Preston et al. (2004) and previous work are also problematic, such as using NO-donors in solution versus the use of direct application of various nitrogen oxides in the gaseous phase. A closer review of these studies, with the proper understanding of nitrogen oxide chemistry, and interpretations of the available literature, would lead to the conclusion that, contrary to the authors' assertions, the Preston et al. (2004) study supports, rather than refutes, earlier findings by Keeley and Fotheringham (1997, 1998a, b, 2000). ?? CAB International 2005.

  10. Current-biased potentiometric NOx sensor for vehicle emissions

    DOEpatents

    Martin, Louis Peter [Castro Valley, CA; Pham, Ai Quoc [San Jose, CA

    2006-12-26

    A nitrogen oxide sensor system for measuring the amount of nitrogen oxide in a gas. A first electrode is exposed to the gas. An electrolyte is positioned in contact with the first electrode. A second electrode is positioned in contact with the electrolyte. A means for applying a fixed current between the first electrode and the second electrode and monitoring the voltage required to maintain the fixed current provides a measurement of the amount of nitrogen oxide in the gas.

  11. Method for removal of nitrogen oxides from stationary combustion sources

    NASA Technical Reports Server (NTRS)

    Cooper, Charles D. (Inventor); Collins, Michelle M. (Inventor); Clausen, III, Christian A. (Inventor)

    2004-01-01

    A method for removing NO.sub.X from gas streams emanating from stationary combustion sources and manufacturing plants utilizes the injection of hydrogen peroxide into the gas stream for rapid gas-phase oxidation of NO to NO.sub.2 and water-soluble nitrogen acids HNO.sub.2 and HNO.sub.3. The nitrogen acids may be removed from the oxidized gas stream by wet scrubbing or by contact with a particulate alkaline material to form a nitrite/nitrate salt.

  12. The applicability of the catalytic wet-oxidation to CELSS

    NASA Technical Reports Server (NTRS)

    Takahashi, Y.; Nitta, K.; Ohya, H.; Oguchi, M.

    1987-01-01

    The wet oxidation catalysis of Au, Pd, Pt, Rh or Ru on a ceramic honeycomb carrier was traced in detail by 16 to 20 repetitive batch tests each. As a result, Pt or Pd on a honeycomb carrier was shown to catalyze complete nitrogen gasification as N2. Though the catalysts which realize both complete nitrogen gasification and complete oxidation could not be found, the Ru+Rh catalyst was found to be most promising. Ru honeycomb catalyzed both nitrification and nitrogen gasification.

  13. Odd nitrogen production by meteoroids

    NASA Technical Reports Server (NTRS)

    Park, C.; Menees, G. P.

    1978-01-01

    The process by which odd nitrogen species (atomic nitrogen and nitric oxide) are formed during atmospheric entry of meteoroids is analyzed theoretically. An ablating meteoroid is assumed to be a point source of mass with a continuum regime evolving in its wake. The amounts of odd nitrogen species, produced by high-temperature reactions of air in the continuum wake, are calculated by numerical integration of chemical rate equations. Flow properties are assumed to be uniform across the wake, and 29 reactions involving five neutral species and five singly ionized species are considered, as well as vibrational and electron temperature nonequilibrium phenomena. The results, when they are summed over the observed mass, velocity, and entry-angle distribution of meteoroids, provide odd-nitrogen-species annual global production rates as functions of altitude. The peak production of nitric oxide is found to occur at an altitude of about 85 km; atomic nitrogen production peaks at about 95 km. The total annual rate for nitric oxide is 40 million kg; for atomic nitrogen it is 170 million kg.

  14. Experimental identification of nitrogen-vacancy complexes in nitrogen implanted silicon

    NASA Astrophysics Data System (ADS)

    Adam, Lahir Shaik; Law, Mark E.; Szpala, Stanislaw; Simpson, P. J.; Lawther, Derek; Dokumaci, Omer; Hegde, Suri

    2001-07-01

    Nitrogen implantation is commonly used in multigate oxide thickness processing for mixed signal complementary metal-oxide-semiconductor and System on a Chip technologies. Current experiments and diffusion models indicate that upon annealing, implanted nitrogen diffuses towards the surface. The mechanism proposed for nitrogen diffusion is the formation of nitrogen-vacancy complexes in silicon, as indicated by ab initio studies by J. S. Nelson, P. A. Schultz, and A. F. Wright [Appl. Phys. Lett. 73, 247 (1998)]. However, to date, there does not exist any experimental evidence of nitrogen-vacancy formation in silicon. This letter provides experimental evidence through positron annihilation spectroscopy that nitrogen-vacancy complexes indeed form in nitrogen implanted silicon, and compares the experimental results to the ab initio studies, providing qualitative support for the same.

  15. Separate Nitrite, Nitric Oxide, and Nitrous Oxide Reducing Fractions from Pseudomonas perfectomarinus

    PubMed Central

    Payne, W. J.; Riley, P. S.; Cox, C. D.

    1971-01-01

    Pseudomonas perfectomarinus was found to grow anaerobically at the expense of nitrate, nitrite, or nitrous oxide but not chlorate or nitric oxide. In several repetitive experiments, anaerobic incubation in culture media containing nitrate revealed that an average of 82% of the cells in aerobically grown populations were converted to the capacity for respiration of nitrate. Although they did not form colonies under these conditions, the bacteria synthesized the denitrifying enzymes within 3 hr in the absence of oxygen or another acceptable inorganic oxidant. This was demonstrated by the ability, after anaerobic incubation, of cells and of extracts to reduce nitrite, nitric oxide, and nitrous oxide to nitrogen. From crude extracts of cells grown on nitrate, nitrite, or nitrous oxide, separate complex fractions were obtained that utilized reduced nicotinamide adenine dinucleotide as the source of electrons for the reduction of (i) nitrite to nitric oxide, (ii) nitric oxide to nitrous oxide, and (iii) nitrous oxide to nitrogen. Gas chromatographic analyses revealed that each of these fractions reduced only one of the nitrogenous oxides. PMID:4324803

  16. Nitrogen oxides at the UTLS: Combining observations from research aircraft and in-service aircraft

    NASA Astrophysics Data System (ADS)

    Ziereis, Helmut; Stratmann, Greta; Schlager, Hans; Gottschaldt, Klaus-Dirk; Rauthe-Schöch, Armin; Zahn, Andreas; Hoor, Peter; van, Peter

    2016-04-01

    Nitrogen oxides have a decisive influence on the chemistry of the upper troposphere and lower stratosphere. They are key constituents of several reaction chains influencing the production of ozone. They also play an essential role in the cycling of hydroxyl radicals and therefore influence the lifetime of methane. Due to their short lifetime and their variety of sources there is still a high uncertainty about the abundance of nitrogen oxides in the UTLS. Dedicated aircraft campaigns aim to study specific atmospheric questions like lightning, long range transport or aircraft emissions. Usually, within a short time period comprehensive measurements are performed within a more or less restricted region. Therefore, especially trace constituents like nitrogen oxides with short lifetime and a variety of different sources are not represented adequately. On the other hand, routine measurements from in-service aircraft allow observations over longer time periods and larger regions. However, it is nearly impossible to influence the scheduling of in-service aircraft and thereby time and space of the observations. Therefore, the combination of dedicated aircraft campaigns and routine observations might supplement each other. For this study we combine nitrogen oxides data sets obtained with the IAGOS-CARIBIC (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container) flying laboratory and with the German research aircraft HALO (High altitude and long range research aircraft). Data have been acquired within the IAGOS-CARIBIC project on a monthly base using a Lufthansa Airbus A340-600 since December 2004. About four flights are performed each month covering predominantly northern mid-latitudes. Additional flights have been conducted to destinations in South America and South Africa. Since 2012 HALO has been operational. Nitrogen oxides measurements have been performed during six missions covering mid latitudes, tropical as well as Polar Regions. With HALO data can also be obtained at altitudes above the flight levels of commercial airliners. First results combining the nitrogen oxides data sets of both platforms are shown, analysing the temporal and regional distribution of nitrogen oxides at the UTLS.

  17. A Continuous Flow System for the Measurement of Ambient Nitrogen Oxides [NO + NO2] Using Rhodamine B Hydrazide as a Chemosensor

    PubMed Central

    Malingappa, Pandurangappa; Yarradoddappa, Venkataramanappa

    2014-01-01

    A new chemosensor has been used to monitor atmospheric nitrogen oxides [NO + NO2] at parts per billion (ppb) level. It is based on the catalytic reaction of nitrogen oxides with rhodamine B hydrazide (RBH) to produce a colored compound through the hydrolysis of the amide bond of the molecule. A simple colorimeter has been used to monitor atmospheric nitrogen dioxide at ppb level. The air samples were purged through a sampling cuvette containing RBH solution using peristaltic pump. The proposed method has been successfully applied to monitor the ambient nitrogen dioxide levels at traffic junction points within the city limits and the results obtained are compared with the standard Griess-Ilosvay method. PMID:25210422

  18. Increasing importance of deposition of reduced nitrogen in the United States

    PubMed Central

    Li, Yi; Schichtel, Bret A.; Walker, John T.; Schwede, Donna B.; Chen, Xi; Lehmann, Christopher M. B.; Puchalski, Melissa A.; Gay, David A.; Collett, Jeffrey L.

    2016-01-01

    Rapid development of agriculture and fossil fuel combustion greatly increased US reactive nitrogen emissions to the atmosphere in the second half of the 20th century, resulting in excess nitrogen deposition to natural ecosystems. Recent efforts to lower nitrogen oxides emissions have substantially decreased nitrate wet deposition. Levels of wet ammonium deposition, by contrast, have increased in many regions. Together these changes have altered the balance between oxidized and reduced nitrogen deposition. Across most of the United States, wet deposition has transitioned from being nitrate-dominated in the 1980s to ammonium-dominated in recent years. Ammonia has historically not been routinely measured because there are no specific regulatory requirements for its measurement. Recent expansion in ammonia observations, however, along with ongoing measurements of nitric acid and fine particle ammonium and nitrate, permit new insight into the balance of oxidized and reduced nitrogen in the total (wet + dry) US nitrogen deposition budget. Observations from 37 sites reveal that reduced nitrogen contributes, on average, ∼65% of the total inorganic nitrogen deposition budget. Dry deposition of ammonia plays an especially key role in nitrogen deposition, contributing from 19% to 65% in different regions. Future progress toward reducing US nitrogen deposition will be increasingly difficult without a reduction in ammonia emissions. PMID:27162336

  19. Nickel supported on nitrogen-doped carbon nanotubes as hydrogen oxidation reaction catalyst in alkaline electrolyte

    DOE PAGES

    Zhuang, Zhongbin; Giles, Stephen A.; Zheng, Jie; ...

    2016-01-14

    The development of a low-cost, high-performance platinum-group-metal-free hydroxide exchange membrane fuel cell is hindered by the lack of a hydrogen oxidation reaction catalyst at the anode. Here we report that a composite catalyst, nickel nanoparticles supported on nitrogen-doped carbon nanotubes, has hydrogen oxidation activity similar to platinum-group metals in alkaline electrolyte. Although nitrogen-doped carbon nanotubes are a very poor hydrogen oxidation catalyst, as a support, it increases the catalytic performance of nickel nanoparticles by a factor of 33 (mass activity) or 21 (exchange current density) relative to unsupported nickel nanoparticles. Density functional theory calculations indicate that the nitrogen-doped support stabilizesmore » the nanoparticle against reconstruction, while nitrogen located at the edge of the nanoparticle tunes local adsorption sites by affecting the d-orbitals of nickel. Here, owing to its high activity and low cost, our catalyst shows significant potential for use in low-cost, high-performance fuel cells.« less

  20. Nickel supported on nitrogen-doped carbon nanotubes as hydrogen oxidation reaction catalyst in alkaline electrolyte

    PubMed Central

    Zhuang, Zhongbin; Giles, Stephen A.; Zheng, Jie; Jenness, Glen R.; Caratzoulas, Stavros; Vlachos, Dionisios G.; Yan, Yushan

    2016-01-01

    The development of a low-cost, high-performance platinum-group-metal-free hydroxide exchange membrane fuel cell is hindered by the lack of a hydrogen oxidation reaction catalyst at the anode. Here we report that a composite catalyst, nickel nanoparticles supported on nitrogen-doped carbon nanotubes, has hydrogen oxidation activity similar to platinum-group metals in alkaline electrolyte. Although nitrogen-doped carbon nanotubes are a very poor hydrogen oxidation catalyst, as a support, it increases the catalytic performance of nickel nanoparticles by a factor of 33 (mass activity) or 21 (exchange current density) relative to unsupported nickel nanoparticles. Density functional theory calculations indicate that the nitrogen-doped support stabilizes the nanoparticle against reconstruction, while nitrogen located at the edge of the nanoparticle tunes local adsorption sites by affecting the d-orbitals of nickel. Owing to its high activity and low cost, our catalyst shows significant potential for use in low-cost, high-performance fuel cells. PMID:26762466

  1. On the use of thermal NF3 as the fluorination and oxidation agent in treatment of used nuclear fuels

    NASA Astrophysics Data System (ADS)

    Scheele, Randall; McNamara, Bruce; Casella, Andrew M.; Kozelisky, Anne

    2012-05-01

    This paper presents results of our investigation on the use of nitrogen trifluoride as a fluorination or fluorination/oxidation agent for separating valuable constituents from used nuclear fuels by exploiting the different volatilities of the constituent fission product and actinide fluorides. Our thermodynamic calculations show that nitrogen trifluoride has the potential to produce volatile fission product and actinide fluorides from oxides and metals that can form volatile fluorides. Simultaneous thermogravimetric and differential thermal analyses show that the oxides of lanthanum, cerium, rhodium, and plutonium are fluorinated but do not form volatile fluorides when treated with nitrogen trifluoride at temperatures up to 550 °C. However, depending on temperature, volatile fluorides or oxyfluorides can form from nitrogen trifluoride treatment of the oxides of niobium, molybdenum, ruthenium, tellurium, uranium, and neptunium. Thermoanalytical studies demonstrate near-quantitative separation of uranium from plutonium in a mixed 80% uranium and 20% plutonium oxide. Our studies of neat oxides and metals suggest that the reactivity of nitrogen trifluoride may be adjusted by temperature to selectively separate the major volatile fuel constituent uranium from minor volatile constituents, such as Mo, Tc, Ru and from the non-volatile fuel constituents based on differences in their reaction temperatures and kinetic behaviors. This reactivity is novel with respect to that reported for other fluorinating reagents F2, BrF5, ClF3.

  2. Chlorine activation indoors and outdoors via surface-mediated reactions of nitrogen oxides with hydrogen chloride

    PubMed Central

    Raff, Jonathan D.; Njegic, Bosiljka; Chang, Wayne L.; Gordon, Mark S.; Dabdub, Donald; Gerber, R. Benny; Finlayson-Pitts, Barbara J.

    2009-01-01

    Gaseous HCl generated from a variety of sources is ubiquitous in both outdoor and indoor air. Oxides of nitrogen (NOy) are also globally distributed, because NO formed in combustion processes is oxidized to NO2, HNO3, N2O5 and a variety of other nitrogen oxides during transport. Deposition of HCl and NOy onto surfaces is commonly regarded as providing permanent removal mechanisms. However, we show here a new surface-mediated coupling of nitrogen oxide and halogen activation cycles in which uptake of gaseous NO2 or N2O5 on solid substrates generates adsorbed intermediates that react with HCl to generate gaseous nitrosyl chloride (ClNO) and nitryl chloride (ClNO2), respectively. These are potentially harmful gases that photolyze to form highly reactive chlorine atoms. The reactions are shown both experimentally and theoretically to be enhanced by water, a surprising result given the availability of competing hydrolysis reaction pathways. Airshed modeling incorporating HCl generated from sea salt shows that in coastal urban regions, this heterogeneous chemistry increases surface-level ozone, a criteria air pollutant, greenhouse gas and source of atmospheric oxidants. In addition, it may contribute to recently measured high levels of ClNO2 in the polluted coastal marine boundary layer. This work also suggests the potential for chlorine atom chemistry to occur indoors where significant concentrations of oxides of nitrogen and HCl coexist. PMID:19620710

  3. 40 CFR Appendix A to Part 55 - Listing of State and Local Requirements Incorporated by Reference Into Part 55, by State

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Prohibitions (Revised 12/6/76) Rule 405 Nitrogen Oxides Emission Standards, Limitations and Prohibitions... (Adopted 7/12/94) Rule 427 Marine Tanker Loading (Adopted 4/26/95) Rule 429 Oxides of Nitrogen and Carbon... Nitrogen from Industrial, Institutional, Commercial Boilers, Steam Generators, and Process Heaters (Adopted...

  4. 76 FR 34021 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Control of Nitrogen...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-10

    ... Promulgation of Air Quality Implementation Plans; Pennsylvania; Control of Nitrogen Oxides Emissions From Glass... Pennsylvania. This revision pertains to the control of nitrogen oxide (NO X ) emissions from glass melting... Plan for the control of NO X from glass melting furnaces. I. Background The SIP revision consists of a...

  5. 40 CFR 89.3 - Acronyms and abbreviations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... National Technical Information Service NO Nitric oxide NO2 Nitrogen dioxide NOX Oxides of nitrogen O2... Selective Enforcement Auditing SI Spark-ignition THC Total hydrocarbon U.S.C. United States Code VOC...

  6. 40 CFR 89.3 - Acronyms and abbreviations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... National Technical Information Service NO Nitric oxide NO2 Nitrogen dioxide NOX Oxides of nitrogen O2... Selective Enforcement Auditing SI Spark-ignition THC Total hydrocarbon U.S.C. United States Code VOC...

  7. 40 CFR 89.3 - Acronyms and abbreviations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... National Technical Information Service NO Nitric oxide NO2 Nitrogen dioxide NOX Oxides of nitrogen O2... Selective Enforcement Auditing SI Spark-ignition THC Total hydrocarbon U.S.C. United States Code VOC...

  8. Field application of nitrogen and phenylacetylene to mitigate greenhouse gas emissions from landfill cover soils: effects on microbial community structure.

    PubMed

    Im, Jeongdae; Lee, Sung-Woo; Bodrossy, Levente; Barcelona, Michael J; Semrau, Jeremy D

    2011-01-01

    Landfills are large sources of CH(4), but a considerable amount of CH(4) can be removed in situ by methanotrophs if their activity can be stimulated through the addition of nitrogen. Nitrogen can, however, lead to increased N(2)O production. To examine the effects of nitrogen and a selective inhibitor on CH(4) oxidation and N(2)O production in situ, 0.5 M of NH(4)Cl and 0.25 M of KNO(3), with and without 0.01% (w/v) phenylacetylene, were applied to test plots at a landfill in Kalamazoo, MI from 2007 November to 2009 July. Nitrogen amendments stimulated N(2)O production but had no effect on CH(4) oxidation. The addition of phenylacetylene stimulated CH(4) oxidation while reducing N(2)O production. Methanotrophs possessing particulate methane monooxygenase and archaeal ammonia-oxidizers (AOAs) were abundant. The addition of nitrogen reduced methanotrophic diversity, particularly for type I methanotrophs. The simultaneous addition of phenylacetylene increased methanotrophic diversity and the presence of type I methanotrophs. Clone libraries of the archaeal amoA gene showed that the addition of nitrogen increased AOAs affiliated with Crenarchaeal group 1.1b, while they decreased with the simultaneous addition of phenylacetylene. These results suggest that the addition of phenylacetylene with nitrogen reduces N(2)O production by selectively inhibiting AOAs and/or type II methanotrophs.

  9. Low-temperature conversion of ammonia to nitrogen in water with ozone over composite metal oxide catalyst.

    PubMed

    Chen, Yunnen; Wu, Ye; Liu, Chen; Guo, Lin; Nie, Jinxia; Chen, Yu; Qiu, Tingsheng

    2018-04-01

    As one of the most important water pollutants, ammonia nitrogen emissions have increased year by year, which has attracted people's attention. Catalytic ozonation technology, which involves production of ·OH radical with strong oxidation ability, is widely used in the treatment of organic-containing wastewater. In this work, MgO-Co 3 O 4 composite metal oxide catalysts prepared with different fabrication conditions have been systematically evaluated and compared in the catalytic ozonation of ammonia (50mg/L) in water. In terms of high catalytic activity in ammonia decomposition and high selectivity for gaseous nitrogen, the catalyst with MgO-Co 3 O 4 molar ratio 8:2, calcined at 500°C for 3hr, was the best one among the catalysts we tested, with an ammonia nitrogen removal rate of 85.2% and gaseous nitrogen selectivity of 44.8%. In addition, the reaction mechanism of ozonation oxidative decomposition of ammonia nitrogen in water with the metal oxide catalysts was discussed. Moreover, the effect of coexisting anions on the degradation of ammonia was studied, finding that SO 4 2- and HCO 3 - could inhibit the catalytic activity while CO 3 2- and Br - could promote it. The presence of coexisting cations had very little effect on the catalytic ozonation of ammonia nitrogen. After five successive reuses, the catalyst remained stable in the catalytic ozonation of ammonia. Copyright © 2017. Published by Elsevier B.V.

  10. Interference of oxygen, carbon dioxide, and water vapor on the analysis for oxides of nitrogen by chemiluminescence

    NASA Technical Reports Server (NTRS)

    Maahs, H. G.

    1975-01-01

    The interference of small concentrations (less than 4 percent by volume) of oxygen, carbon dioxide, and water vapor on the analysis for oxides of nitrogen by chemiluminescence was measured. The sample gas consisted primarily of nitrogen, with less than 100 parts per million concentration of nitric oxide, and with small concentrations of oxygen, carbon dioxide, and water vapor added. Results obtained under these conditions indicate that although oxygen does not measurably affect the analysis for nitric oxide, the presence of carbon dioxide and water vapor causes the indicated nitric oxide concentration to be too low. An interference factor - defined as the percentage change in indicated nitric oxide concentration (relative to the true nitric oxide concentration) divided by the percent interfering gas present - was determined for carbon dioxide to be -0.60 + or - 0.04 and for water vapor to be -2.1 + or - 0.3.

  11. Treatment of Ammonia Nitrogen Wastewater in Low Concentration by Two-Stage Ozonization.

    PubMed

    Luo, Xianping; Yan, Qun; Wang, Chunying; Luo, Caigui; Zhou, Nana; Jian, Chensheng

    2015-09-23

    Ammonia nitrogen wastewater (about 100 mg/L) was treated by two-stage ozone oxidation method. The effects of ozone flow rate and initial pH on ammonia removal were studied, and the mechanism of ammonia nitrogen removal by ozone oxidation was discussed. After the primary stage of ozone oxidation, the ammonia removal efficiency reached 59.32% and pH decreased to 6.63 under conditions of 1 L/min ozone flow rate and initial pH 11. Then, the removal efficiency could be over 85% (the left ammonia concentration was lower than 15 mg/L) after the second stage, which means the wastewater could have met the national discharge standards of China. Besides, the mechanism of ammonia removal by ozone oxidation was proposed by detecting the products of the oxidation: ozone oxidation directly and ·OH oxidation; ammonia was mainly transformed into NO₃(-)-N, less into NO₂(-)-N, not into N₂.

  12. “Transference Ratios” to Predict Total Oxidized Sulfur and Nitrogen Deposition – Part II, Modeling Results

    EPA Science Inventory

    The current study examines predictions of transference ratios and related modeled parameters for oxidized sulfur and oxidized nitrogen using five years (2002-2006) of 12-km grid cell-specific annual estimates from EPA’s Community Air Quality Model (CMAQ) for five selected sub-re...

  13. 40 CFR 52.235 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Control strategy for ozone: Oxides of... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the Monterey Bay Unified Air Pollution Control District on April 26, 1994 for the Monterey Bay ozone nonattainment area...

  14. 40 CFR 52.136 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Control strategy for ozone: Oxides of... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the State of Arizona on April 13, 1994 for the Maricopa County ozone nonattainment area from the NOX RACT requirements...

  15. 40 CFR 52.136 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy for ozone: Oxides of... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the State of Arizona on April 13, 1994 for the Maricopa County ozone nonattainment area from the NOX RACT requirements...

  16. 40 CFR 52.235 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Control strategy for ozone: Oxides of... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the Monterey Bay Unified Air Pollution Control District on April 26, 1994 for the Monterey Bay ozone nonattainment area...

  17. 40 CFR 52.235 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Control strategy for ozone: Oxides of... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the Monterey Bay Unified Air Pollution Control District on April 26, 1994 for the Monterey Bay ozone nonattainment area...

  18. 40 CFR 52.136 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Control strategy for ozone: Oxides of... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the State of Arizona on April 13, 1994 for the Maricopa County ozone nonattainment area from the NOX RACT requirements...

  19. 40 CFR 52.136 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Control strategy for ozone: Oxides of... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the State of Arizona on April 13, 1994 for the Maricopa County ozone nonattainment area from the NOX RACT requirements...

  20. 40 CFR 52.235 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy for ozone: Oxides of... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the Monterey Bay Unified Air Pollution Control District on April 26, 1994 for the Monterey Bay ozone nonattainment area...

  1. 40 CFR 52.136 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Control strategy for ozone: Oxides of... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the State of Arizona on April 13, 1994 for the Maricopa County ozone nonattainment area from the NOX RACT requirements...

  2. 40 CFR 52.235 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Control strategy for ozone: Oxides of... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the Monterey Bay Unified Air Pollution Control District on April 26, 1994 for the Monterey Bay ozone nonattainment area...

  3. 40 CFR 60.49b - Reporting and recordkeeping requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... into the oxidation zone. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted, the NOX emission limit for fossil fuel in § 60.44b(a) applies. (ii) When natural gas and chemical by... back into the combustion air. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted...

  4. 40 CFR 60.49b - Reporting and recordkeeping requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... into the oxidation zone. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted, the NOX emission limit for fossil fuel in § 60.44b(a) applies. (ii) When natural gas and chemical by... back into the combustion air. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted...

  5. 40 CFR 60.49b - Reporting and recordkeeping requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... into the oxidation zone. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted, the NOX emission limit for fossil fuel in § 60.44b(a) applies. (ii) When natural gas and chemical by... back into the combustion air. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted...

  6. 40 CFR 60.49b - Reporting and recordkeeping requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... into the oxidation zone. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted, the NOX emission limit for fossil fuel in § 60.44b(a) applies. (ii) When natural gas and chemical by... back into the combustion air. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted...

  7. 40 CFR 60.49b - Reporting and recordkeeping requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... into the oxidation zone. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted, the NOX emission limit for fossil fuel in § 60.44b(a) applies. (ii) When natural gas and chemical by... back into the combustion air. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted...

  8. Nitrogen-doped hierarchical porous carbon with high surface area derived from graphene oxide/pitch oxide composite for supercapacitors.

    PubMed

    Ma, Yuan; Ma, Chang; Sheng, Jie; Zhang, Haixia; Wang, Ranran; Xie, Zhenyu; Shi, Jingli

    2016-01-01

    A nitrogen-doped hierarchical porous carbon has been prepared through one-step KOH activation of pitch oxide/graphene oxide composite. At a low weight ratio of KOH/composite (1:1), the as-prepared carbon possesses high specific surface area, rich nitrogen and oxygen, appropriate mesopore/micropore ratio and considerable small-sized mesopores. The addition of graphene oxide plays a key role in forming 4 nm mesopores. The sample PO-GO-16 presents the characteristics of large surface area (2196 m(2) g(-1)), high mesoporosity (47.6%), as well as rich nitrogen (1.52 at.%) and oxygen (6.9 at.%). As a result, PO-GO-16 electrode shows an outstanding capacitive behavior: high capacitance (296 F g(-1)) and ultrahigh-rate performance (192 F g(-1) at 10 A g(-1)) in 6 M KOH aqueous electrolyte. The balanced structure characteristic, low-cost and high performance, make the porous carbon a promising electrode material for supercapacitors. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. The formation of nitrogen-containing organic oxidation products in a heavily polluted urban environment

    NASA Astrophysics Data System (ADS)

    Chen, Q.; Cheng, X.; Zheng, Y.; Li, Y.; Zhu, T.; Zhang, Q.; Canagaratna, M. R.; Nowark, J.; Worsnop, D. R.

    2017-12-01

    Nitrogen-containing organic oxidation products are important species that may contribute to secondary organic aerosol and to redistribute nitrogen oxides through photolysis and oxidation. We deployed a nitrate ion chemical ionization time-of-flight mass spectrometer and a long time-of-flight aerosol mass spectrometer in Beijing for various seasons to study the nitrogen-containing organic species in both gas and particle phases. High concentrations of nitrated phenols were observed in both winter and summer, due to contributions from both primary and secondary sources. The concentrations of gaseous dinitrophenols tracked the severe haze events and correlated well with many highly oxygenated organic molecules. We also identified mass spectral tracers for quantifying organic nitrates. Significant photochemical production of nitrate and organic nitrates were evident during severe haze events, which may contribute to persistent particle formation. The findings are consistent with observed high OH turnover rates, highlighting the importance of gaseous oxidation pathways on persistent particle formation during haze.

  10. 91. VIEW OF OXYGEN AND GASEOUS NITROGEN TANKS AND OXIDIZER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    91. VIEW OF OXYGEN AND GASEOUS NITROGEN TANKS AND OXIDIZER APRON FROM NORTH - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  11. Crystalline boron nitride aerogels

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zettl, Alexander K.; Rousseas, Michael; Goldstein, Anna P.

    This disclosure provides methods and materials related to boron nitride aerogels. For example, one aspect relates to a method for making an aerogel comprising boron nitride, comprising: (a) providing boron oxide and an aerogel comprising carbon; (b) heating the boron oxide to melt the boron oxide and heating the aerogel; (c) mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide; and (d) converting at least a portion of the carbon to boron nitride to obtain the aerogel comprising boron nitride. Another aspect relates to a method for making an aerogel comprising boron nitride, comprising heating boron oxidemore » and an aerogel comprising carbon under flow of a nitrogen-containing gas, wherein boron oxide vapor and the nitrogen-containing gas convert at least a portion of the carbon to boron nitride to obtain the aerogel comprising boron nitride.« less

  12. Achieving lower nitrogen balance and higher nitrogen recovery efficiency reduces nitrous oxide emissions in North America’s maize cropping systems

    USDA-ARS?s Scientific Manuscript database

    Few studies have assessed the common, yet unproven, hypothesis that an increase of plant nitrogen (N) uptake and/or recovery efficiency (NRE) will reduce nitrous oxide (N2O) emission during crop production. Understanding the relationships between N2O emissions and crop N uptake and use efficiency p...

  13. Life-Cycle Cost and Environmental Assessment of Decentralized Nitrogen Recovery Using Ion Exchange from Source-Separated Urine through Spatial Modeling.

    PubMed

    Kavvada, Olga; Tarpeh, William A; Horvath, Arpad; Nelson, Kara L

    2017-11-07

    Nitrogen standards for discharge of wastewater effluent into aquatic bodies are becoming more stringent, requiring some treatment plants to reduce effluent nitrogen concentrations. This study aimed to assess, from a life-cycle perspective, an innovative decentralized approach to nitrogen recovery: ion exchange of source-separated urine. We modeled an approach in which nitrogen from urine at individual buildings is sorbed onto resins, then transported by truck to regeneration and fertilizer production facilities. To provide insight into impacts from transportation, we enhanced the traditional economic and environmental assessment approach by combining spatial analysis, system-scale evaluation, and detailed last-mile logistics modeling using the city of San Francisco as an illustrative case study. The major contributor to energy intensity and greenhouse gas (GHG) emissions was the production of sulfuric acid to regenerate resins, rather than transportation. Energy and GHG emissions were not significantly sensitive to the number of regeneration facilities. Cost, however, increased with decentralization as rental costs per unit area are higher for smaller areas. The metrics assessed (unit energy, GHG emissions, and cost) were not significantly influenced by facility location in this high-density urban area. We determined that this decentralized approach has lower cost, unit energy, and GHG emissions than centralized nitrogen management via nitrification-denitrification if fertilizer production offsets are taken into account.

  14. Estimation of the nitric oxide formed from hydroxylamine by Nitrosomonas

    PubMed Central

    Anderson, J. H.

    1965-01-01

    1. Nitric oxide that was produced by reducing nitrite with an excess of acidified potassium iodide under nitrogen in Warburg respirometer flasks was rapidly absorbed by a solution of permanganate in sodium hydroxide held in the side arm. A small amount of nitrous oxide (or nitrogen) that was also produced was not absorbed. 2. By using a quantitative method for the recovery of nitrite from samples of the alkaline permanganate, it was found that the sum of the nitrite N formed and the residual nitrous oxide N was equivalent to the nitrite N used to generate the gases. These results showed that alkaline permanganate completely oxidized nitric oxide to nitrite. The method was suitable for determining 0·4–20 μmoles of nitric oxide. 3. The technique was used to determine the nitric oxide content of the nitrogenous gas that was produced anaerobically from hydroxylamine by an extract of the autotrophic nitrifying micro-organism Nitrosomonas in the presence of methylene blue as electron acceptor. PMID:14342235

  15. Method for the detection of nitro-containing compositions using ultraviolet photolysis

    DOEpatents

    Reagen, William K.; Lancaster, Gregory D.; Partin, Judy K.; Moore, Glenn A.

    2000-01-01

    A method for detecting nitro-containing compositions (e.g. nitrate/nitrite materials) in water samples and on solid substrates. In a water sample, ultraviolet light is applied to the sample so that dissolved nitro compositions therein will photolytically dissociate into gaseous nitrogen oxides (NO.sub.2(g) and/or NO.sub.(g)). A carrier gas is then introduced into the sample to generate a gaseous stream which includes the carrier gas combined with any gaseous nitrogen oxides. The carrier gas is thereafter directed into a detector. To detect nitro-compositions on solid substrates, ultraviolet light is applied thereto. A detector is then used to detect any gaseous nitrogen oxides which are photolytically generated during ultraviolet illumination. An optional carrier gas may be applied to the substrate during illumination to produce a gaseous stream which includes the carrier gas and any gaseous nitrogen oxides. The gaseous stream is then supplied to the detector.

  16. Metabolism of Nitrogen Oxides in Ammonia-Oxidizing Bacteria

    NASA Astrophysics Data System (ADS)

    Kozlowski, J.; Stein, L. Y.

    2014-12-01

    Ammonia-oxidizing bacteria (AOB) are key microorganisms in the transformation of nitrogen intermediates in most all environments. Until recently there was very little work done to elucidate the physiology of ammonia-oxidizing bacteria cultivated from variable trophic state environments. With a greater variety of ammonia-oxidizers now in pure culture the importance of comparative physiological and genomic analysis is crucial. Nearly all known physiology of ammonia-oxidizing bacteria lies within the Nitrosomonas genus with Nitrosomonas europaea strain ATCC 19718 as the model. To more broadly characterize and understand the nature of obligate ammonia chemolithotrophy and the contribution of AOB to production of nitrogen oxides, Nitrosomonas spp. and Nitrosospira spp. isolated from variable trophic states and with sequenced genomes, were utilized. Instantaneous ammonia- and hydroxylamine-oxidation kinetics as a function of oxygen and substrate concentration were measured using an oxygen micro-sensor. The pathway intermediates nitric oxide and nitrous oxide were measured in real time using substrate-specific micro-sensors to elucidate whether production of these molecules is stoichiometric with rates of substrate oxidation. Genomic inventory was compared among the strains to identify specific pathways and modules to explain physiological differences in kinetic rates and production of N-oxide intermediates as a condition of their adaptation to different ammonium concentrations. This work provides knowledge of how nitrogen metabolism is differentially controlled in AOB that are adapted to different concentrations of ammonium. Overall, this work will provide further insight into the control of ammonia oxidizing chemolithotrophy across representatives of the Nitrosomonas and Nitrosospira genus, which can then be applied to examine additional genome-sequenced AOB isolates.

  17. Nitrogen enriched combustion of a natural gas internal combustion engine to reduce NO.sub.x emissions

    DOEpatents

    Biruduganti, Munidhar S.; Gupta, Sreenath Borra; Sekar, R. Raj; McConnell, Steven S.

    2008-11-25

    A method and system for reducing nitrous oxide emissions from an internal combustion engine. An input gas stream of natural gas includes a nitrogen gas enrichment which reduces nitrous oxide emissions. In addition ignition timing for gas combustion is advanced to improve FCE while maintaining lower nitrous oxide emissions.

  18. Nitrogen management impacts nitrous oxide emissions under varying cotton irrigation systems in the American Desert Southwest

    USDA-ARS?s Scientific Manuscript database

    Irrigation of food and fiber crops worldwide continues to increase. Nitrogen (N) from fertilizers is a major source of the potent greenhouse gas nitrous oxide (N2O) in irrigated cropping systems. Nitrous oxide emissions data are scarce for crops in the arid Western US. The objective of these studies...

  19. Modeling of recovery mechanism of ozone zero phenomenaby adding small amount of nitrogen in atmospheric pressure oxygen dielectric barrier discharges

    NASA Astrophysics Data System (ADS)

    Akashi, Haruaki; Yoshinaga, Tomokazu

    2013-09-01

    Ozone zero phenomena in an atmospheric pressure oxygen dielectric barrier discharges have been one of the major problems during a long time operation of ozone generators. But it is also known that the adding a small amount of nitrogen makes the recover from the ozone zero phenomena. To make clear the mechanism of recovery, authors have been simulated the discharges with using the results of Ref. 3. As a result, the recovery process can be seen and ozone density increased. It is found that the most important species would be nitrogen atoms. The reaction of nitrogen atoms and oxygen molecules makes oxygen atoms which is main precursor species of ozone. This generation of oxygen atoms is effective to increase ozone. The dependence of oxygen atom density (nO) and nitrogen atom density (nN) ratio was examined in this paper. In the condition of low nN/nO ratio case, generation of nitrogen oxide is low, and the quenching of ozone by the nitrogen oxide would be low. But in the high ratio condition, the quenching of ozone by nitrogen oxide would significant. This work was supported by KAKENHI(23560352).

  20. After 'dieselgate': Regulations or economic incentives for a successful environmental policy?

    NASA Astrophysics Data System (ADS)

    Zachariadis, Theodoros

    2016-08-01

    In September 2015 the U.S. Environmental Protection Agency announced that it started investigations against the automaker Volkswagen for illegally installing software that allowed some diesel-powered vehicle models to pass stringent emission tests for type-approval. Although generally prohibited, modern software makes it feasible for vehicles to detect an emission test and modulate engine operation or emission control accordingly. It has also been well known to experts worldwide - and readers of this Journal - that emission tests for motor vehicles are conducted with outdated test procedures which do not reflect today's actual driving conditions and enable automakers to exploit 'flexibilities' so as to yield artificially low emission results. For example, on-road carbon dioxide (CO2) emissions of cars that entered the European market in 2014 were reportedly 40% higher than their formal test emissions, while this gap was less than 10% in the early 2000s (Tietge et al., 2015). In the case of health-related pollutant nitrogen oxides (NOx), this gap seems to be markedly higher, in particular for diesel-powered cars (Weiss et al., 2012) - whereas this does not seem to be a serious problem for other air pollutants. In internal combustion engines of motor vehicles there is still a trade-off between NOx emissions and fuel efficiency (and hence CO2 emissions): a fast combustion with high temperatures is optimal for maximum fuel efficiency and minimum CO2 emissions, whereas these conditions give rise to higher NOx emissions. Conversely, NOx control techniques such as exhaust gas recirculation reduce combustion temperature and often lead to lower fuel efficiency. In short, it becomes ever more difficult for internal combustion engines to meet the increasingly stringent legislated standards for some air pollutants and carbon dioxide at the same time. This increases the probability of applying legal and illegal defeat strategies.

  1. Integrated assessment of health, crop, and climate impacts of mitigating excess diesel NOx emissions in 11 major vehicle markets

    NASA Astrophysics Data System (ADS)

    Henze, D. K.; Anenberg, S.; Miller, J.; Vicente, F.; Du, L.; Emberson, L.; Lacey, F.; Malley, C.; Minjares, R. J.

    2016-12-01

    Vehicle emissions contribute to tropospheric ozone and fine particulate matter (PM2.5), impacting human health, crop yields, and climate worldwide. Diesel cars, trucks, and buses produce 70% of global land transportation emissions of nitrogen oxides (NOx), a key PM2.5 and ozone precursor. Despite progressive tightening of regulated NOx emission limits in leading markets, current diesel vehicles emit far more NOx under real-world operating conditions than during laboratory certification testing. Here we show that real-world diesel NOx emissions in 11 markets representing 80% of global diesel vehicle sales are on average 24% higher than certification limits indicate. This excess NOx contributed an estimated 33,000 additional ozone- and PM2.5-related premature deaths globally in 2015, including 6% of all EU-28 ozone- and PM2.5-related premature deaths. Next-generation diesel NOx standards and in-use compliance (more stringent than Euro 6/VI standards) could avoid 358,000 (5%) of global PM2.5- and ozone-related premature deaths in 2040 and up to 4% of ozone-related crop production loss regionally. Impacts of NOx-induced changes in aerosols, methane, and ozone on the global climate are found to present a small net positive radiative forcing (i.e., climate disbenefit), likely outweighed by the climate benefits of reductions to co-emitted black carbon aerosol. In some markets (Australia, Brazil, China, Mexico, and Russia), Euro 6/VI standards alone can achieve most (72-98%) of these health benefits. In India and the EU-28, reducing Euro 6 real-world NOx emissions through strengthened type-approval and in-use emissions testing programs (including market surveillance and expanded emissions test procedure boundaries) would achieve one-third of the health benefits from adopting next generation standards. Our results indicate that implementing stringent and technically feasible NOx emission regulations for diesel vehicles can substantially improve public health.

  2. NOx emissions in China: historical trends and future perspectives

    NASA Astrophysics Data System (ADS)

    Zhao, B.; Wang, S. X.; Liu, H.; Xu, J. Y.; Fu, K.; Klimont, Z.; Hao, J. M.; He, K. B.; Cofala, J.; Amann, M.

    2013-10-01

    Nitrogen oxides (NOx) are key pollutants for the improvement of ambient air quality. Within this study we estimated the historical NOx emissions in China for the period 1995-2010, and calculated future NOx emissions every five years until 2030 under six emission scenarios. Driven by the fast growth of energy consumption, we estimate the NOx emissions in China increased rapidly from 11.0 Mt in 1995 to 26.1 Mt in 2010. Power plants, industry and transportation were major sources of NOx emissions, accounting for 28.4%, 34.0%, and 25.4% of the total NOx emissions in 2010, respectively. Two energy scenarios, a business as usual scenario (BAU) and an alternative policy scenario (PC), were developed to project future energy consumption. In 2030, total energy consumption is projected to increase by 64% and 27% from 2010 level respectively. Three sets of end-of-pipe pollution control measures, including baseline, progressive, and stringent control case, were developed for each energy scenario, thereby constituting six emission scenarios. By 2030, the total NOx emissions are projected to increase (compared to 2010) by 36% in the baseline while policy cases result in reduction up to 61% in the most ambitious case with stringent control measures. More than a third of the reduction achieved by 2030 between least and most ambitious scenario comes from power sector, and more than half is distributed equally between industry and transportation sectors. Selective catalytic reduction dominates the NOx emission reductions in power plants, while life style changes, control measures for industrial boilers and cement production are major contributors to reductions in industry. Timely enforcement of legislation on heavy-duty vehicles would contribute significantly to NOx emission reductions. About 30% of the NOx emission reduction in 2020 and 40% of the NOx emission reduction in 2030 could be treated as the ancillary benefit of energy conservation. Sensitivity analysis was conducted to explore the impact of key factors on future emissions.

  3. NO.sub.x reduction method

    DOEpatents

    Sekar, Ramanujam R.; Hoppie, Lyle O.

    1996-01-01

    A method of reducing oxides of nitrogen (NO.sub.X) in the exhaust of an internal combustion engine includes producing oxygen enriched air and nitrogen enriched air by an oxygen enrichment device. The oxygen enriched air may be provided to the intake of the internal combustion engine for mixing with fuel. In order to reduce the amount of NO.sub.X in the exhaust of the internal combustion engine, the molecular nitrogen in the nitrogen enriched air produced by the oxygen enrichment device is subjected to a corona or arc discharge so as to create a plasma and as a result, atomic nitrogen. The resulting atomic nitrogen then is injected into the exhaust of the internal combustion engine causing the oxides of nitrogen in the exhaust to be reduced into nitrogen and oxygen. In one embodiment of the present invention, the oxygen enrichment device that produces both the oxygen and nitrogen enriched air can include a selectively permeable membrane.

  4. Examination of Treatment Methods for Cyanide Wastes.

    DTIC Science & Technology

    1979-05-15

    industry,is alkaline chlorination. This process oxidizes cyanide to cyanate followed by complete decomposition yielding carbon dioxide and nitrogen or...decomposition yielding carbon dioxide and nitrogen, or ammonium salts depending on final treatment methods. The major oxidizing agents that have been...2H20 (X represents a cation.) 29 NADC-78198-60 This liberates carbon dioxide and nitrogen gas as end products. Possible acid hydrolysis has been

  5. Microbial nitrogen transformation potential in surface run-off leachate from a tropical landfill

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mangimbulude, Jubhar C.; Straalen, Nico M. van; Roeling, Wilfred F.M., E-mail: wilfred.roling@falw.vu.nl

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Microbial nitrogen transformations can alleviate toxic ammonium discharge. Black-Right-Pointing-Pointer Aerobic ammonium oxidation was rate-limiting in Indonesian landfill leachate. Black-Right-Pointing-Pointer Organic nitrogen ammonification was most dominant. Black-Right-Pointing-Pointer Anaerobic nitrate reduction and ammonium oxidation potential were also high. Black-Right-Pointing-Pointer A two-stage aerobic-anaerobic nitrogen removal system needs to be implemented. - Abstract: Ammonium is one of the major toxic compounds and a critical long-term pollutant in landfill leachate. Leachate from the Jatibarang landfill in Semarang, Indonesia, contains ammonium in concentrations ranging from 376 to 929 mg N L{sup -1}. The objective of this study was to determine seasonal variation in themore » potential for organic nitrogen ammonification, aerobic nitrification, anaerobic nitrate reduction and anaerobic ammonium oxidation (anammox) at this landfilling site. Seasonal samples from leachate collection treatment ponds were used as an inoculum to feed synthetic media to determine potential rates of nitrogen transformations. Aerobic ammonium oxidation potential (<0.06 mg N L{sup -1} h{sup -1}) was more than a hundred times lower than the anaerobic nitrogen transformation processes and organic nitrogen ammonification, which were of the same order of magnitude. Anaerobic nitrate oxidation did not proceed beyond nitrite; isolates grown with nitrate as electron acceptor did not degrade nitrite further. Effects of season were only observed for aerobic nitrification and anammox, and were relatively minor: rates were up to three times higher in the dry season. To completely remove the excess ammonium from the leachate, we propose a two-stage treatment system to be implemented. Aeration in the first leachate pond would strongly contribute to aerobic ammonium oxidation to nitrate by providing the currently missing oxygen in the anaerobic leachate and allowing for the growth of ammonium oxidisers. In the second pond the remaining ammonium and produced nitrate can be converted by a combination of nitrate reduction to nitrite and anammox. Such optimization of microbial nitrogen transformations can contribute to alleviating the ammonium discharge to surface water draining the landfill.« less

  6. EnviroAtlas - Atmospheric Nitrogen Deposition by 12-digit HUC for the Conterminous United States (2002)

    EPA Pesticide Factsheets

    This EnviroAtlas dataset includes annual nitrogen and sulfur deposition within each 12-digit HUC subwatershed for the year 2002. Values are provided for total oxidized nitrogen (HNO3, NO, NO2, N2O5, NH3, HONO, PAN, organic nitrogen, and particulate NO3), oxidized nitrogen wet deposition, oxidized nitrogen dry deposition, total reduced nitrogen (NH3 and particulate NH4), reduced nitrogen dry deposition, reduced nitrogen wet deposition, total dry nitrogen deposition, total wet nitrogen deposition, total nitrogen deposition (wet+dry), total sulfur (SO2 + particulate SO4) dry deposition, total sulfur wet deposition, and total sulfur deposition. The dataset is based on output from the Community Multiscale Air Quality modeling system (CMAQ) v5.0.2 run using the bidirectional flux option for the 12-km grid size for the US, Canada, and Mexico. The CMAQ output has been post-processed to adjust the wet deposition for errors in the location and amount of precipitation and for regional biases in the TNO3 (HNO3 + NO3), NHx (NH4 + NH3), and sulfate wet deposition. Model predicted values of dry deposition were not adjusted. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadab

  7. EnviroAtlas - Atmospheric Nitrogen and Sulfur Deposition by 12-digit HUC for the Conterminous United States (2011)

    EPA Pesticide Factsheets

    This EnviroAtlas dataset includes annual nitrogen and sulfur deposition within each 12-digit HUC subwatershed for the year 2011. Values are provided for total oxidized nitrogen (HNO3, NO, NO2, N2O5, NH3, HONO, PAN, organic nitrogen, and particulate NO3), oxidized nitrogen wet deposition, oxidized nitrogen dry deposition, total reduced nitrogen (NH3 and particulate NH4), reduced nitrogen dry deposition, reduced nitrogen wet deposition, total dry nitrogen deposition, total wet nitrogen deposition, total nitrogen deposition (wet+dry), total sulfur (SO2 + particulate SO4) dry deposition, total sulfur wet deposition, and total sulfur deposition. The dataset is based on output from the Community Multiscale Air Quality modeling system (CMAQ) run using the bidirectional flux option for the 12-km grid size for the US, Canada, and Mexico. The CMAQ output has been post-processed to adjust the wet deposition for errors in the location and amount of precipitation and for regional biases in the TNO3 (HNO3 + NO3), NHx (NH4 + NH3), and sulfate wet deposition. Model predicted values of dry deposition were not adjusted. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data

  8. EnviroAtlas - Atmospheric Nitrogen Deposition by 12-digit HUC for the Conterminous United States (2006)

    EPA Pesticide Factsheets

    This EnviroAtlas dataset includes annual nitrogen and sulfur deposition within each 12-digit HUC subwatershed for the year 2006. Values are provided for total oxidized nitrogen (HNO3, NO, NO2, N2O5, NH3, HONO, PAN, organic nitrogen, and particulate NO3), oxidized nitrogen wet deposition, oxidized nitrogen dry deposition, total reduced nitrogen (NH3 and particulate NH4), reduced nitrogen dry deposition, reduced nitrogen wet deposition, total dry nitrogen deposition, total wet nitrogen deposition, total nitrogen deposition (wet+dry), total sulfur (SO2 + particulate SO4) dry deposition, total sulfur wet deposition, and total sulfur deposition. The dataset is based on output from the Community Multiscale Air Quality modeling system (CMAQ) run using the bidirectional flux option for the 12-km grid size for the US, Canada, and Mexico. The CMAQ output has been post-processed to adjust the wet deposition for errors in the location and amount of precipitation and for regional biases in the TNO3 (HNO3 + NO3), NHx (NH4 + NH3), and sulfate wet deposition. Model predicted values of dry deposition were not adjusted. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable dat

  9. Effect of nitrogen doping on structural, morphological, optical and electrical properties of radio frequency magnetron sputtered zinc oxide thin films

    NASA Astrophysics Data System (ADS)

    Perumal, R.; Hassan, Z.

    2016-06-01

    Zinc oxide receives remarkable attention due to its several attractive physical properties. Zinc oxide thin films doped with nitrogen were grown by employing RF magnetron sputtering method at room temperature. Doping was accomplished in gaseous medium by mixing high purity nitrogen gas along with argon sputtering gas. Structural studies confirmed the high crystalline nature with c-axis oriented growth of the nitrogen doped zinc oxide thin films. The tensile strain was developed due to the incorporation of the nitrogen into the ZnO crystal lattice. Surface roughness of the grown films was found to be decreased with increasing doping level was identified through atomic force microscope analysis. The presenting phonon modes of each film were confirmed through FTIR spectral analysis. The increasing doping level leads towards red-shifting of the cut-off wavelength due to decrement of the band gap was identified through UV-vis spectroscopy. All the doped films exhibited p-type conductivity was ascertained using Hall measurements and the obtained results were presented.

  10. Effect of N2 flow during deposition on p-type ZnO film

    NASA Astrophysics Data System (ADS)

    Lin, Chiung-Wei; Liu, Bor-Chang

    2017-01-01

    In this study, the influence of a nitrogen source on p-type conductive ZnO films was studied. Rapid thermal oxidation was conducted to oxidize ZnN films and convert them to ZnO films. When an as-deposited ZnN film was prepared at a high nitrogen gas flow rate, the converted ZnO film possessed many acceptors and showed stable p-type conduction. This p-type conduction was attributed to the nitrogen gas flow providing many “No” states, which act as acceptors within the processed ZnO film. It was found that the as-deposited ZnN film prepared at a high nitrogen gas flow rate is oxidized slightly so that only a few nitrogen atoms were replaced by oxygen. The carrier concentration and mobility of the optimized oxidized ZnN film were 9.76 × 1017 cm-3 and 62.78 cm2 V-1 s-1, respectively. A good rectified current-voltage characteristic with a turn-on voltage of 3.65 V was achieved for the optimized ZnO:N/ZnO junction.

  11. Analysis of nitrification in agricultural soil and improvement of nitrogen circulation with autotrophic ammonia-oxidizing bacteria.

    PubMed

    Matsuno, Toshihide; Horii, Sachie; Sato, Takanobu; Matsumiya, Yoshiki; Kubo, Motoki

    2013-02-01

    Accumulations of inorganic nitrogen (NH₄⁺, NO₂⁻, and NO₃⁻) were analyzed to evaluate the nitrogen circulation activity in 76 agricultural soils. Accumulation of NH₄⁺ was observed, and the reaction of NH₄⁺→ NO₂⁻ appeared to be slower than that of NO₂⁻ → NO₃⁻ in agricultural soil. Two autotrophic and five heterotrophic ammonia-oxidizing bacteria (AOB) were isolated and identified from the soils, and the ammonia-oxidizing activities of the autotrophic AOB were 1.0 × 10³-1.0 × 10⁶ times higher than those of heterotrophic AOB. The relationship between AOB number, soil bacterial number, and ammonia-oxidizing activity was investigated with 30 agricultural soils. The ratio of autotrophic AOB number was 0.00032-0.26% of the total soil bacterial number. The soil samples rich in autotrophic AOB (>1.0 × 10⁴ cells/g soil) had a high nitrogen circulation activity, and additionally, the nitrogen circulation in the agricultural soil was improved by controlling the autotrophic AOBs.

  12. 75 FR 14116 - Approval of Implementation Plans of Wisconsin: Nitrogen Oxides Reasonably Available Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-24

    ... Annealing Furnace. Asphalt Plants =>65 mmBtu/hr... Gaseous fuel, 0.15 lbs/mmBtu. Distillate oil, 0.20 lbs/mm... relations, Nitrogen oxides, Ozone, Particulate matter, Reporting and recordkeeping requirements, Sulfur...

  13. Correlation of black smoke and nitrogen oxides emissions through field testing of in-use diesel vehicles.

    PubMed

    Lin, Cherng-Yuan; Chen, Lih-Wei; Wang, Li-Ting

    2006-05-01

    Diesel vehicles are one of the major forms of transportation, especially in metropolitan regions. However, air pollution released from diesel vehicles causes serious damage to both human health and the environment, and as a result is of great public concern. Nitrogen oxides and black smoke are two significant emissions from diesel engines. Understanding the correlation between these two emissions is an important step toward developing the technology for an appropriate strategy to control or eliminate them. This study field-tested 185 diesel vehicles at an engine dynamometer station for their black smoke reflectivity and nitrogen oxides concentration to explore the correlation between these two pollutants. The test results revealed that most of the tested diesel vehicles emitted black smoke with low reflectivity and produced low nitrogen oxides concentration. The age of the tested vehicles has a significant influence on the NOx emission. The older the tested vehicles, the higher the NOx concentrations emitted, however, there was no obvious correlation between the age of the tested diesel vehicles and the black smoke reflectivity. In addition, if the make and engine displacement volume of the tested diesel vehicles are not taken into consideration, then the correlation between the black smoke reflectivity and nitrogen oxides emission weakens. However, when the tested vehicles were classified into various groups based on their makes and engine displacement volumes, then the make of a tested vehicle became a dominant factor for both the quantity and the trend of the black smoke reflectivity, as well as the NOx emission. Higher emission indices of black smoke reflectivity and nitrogen oxides were observed if the diesel vehicles were operated at low engine speed and full engine load conditions. Moreover, the larger the displacement volume of the engine of the tested vehicle, the lower the emission indices of both black smoke reflectivity and nitrogen oxides emitted. The emission indices of black smokes reflectivity and nitrogen oxides emission of the tested diesel vehicles were also influenced by the make of the vehicle. It was observed that the emission indices of black smoke reflectivity decreased nearly linearly with the increase of the emission indices of NOx for the tested vehicles belonging to the same group of make and engine displacement volume.

  14. Mathematical modeling of wastewater-derived biodegradable dissolved organic nitrogen.

    PubMed

    Simsek, Halis

    2016-11-01

    Wastewater-derived dissolved organic nitrogen (DON) typically constitutes the majority of total dissolved nitrogen (TDN) discharged to surface waters from advanced wastewater treatment plants (WWTPs). When considering the stringent regulations on nitrogen discharge limits in sensitive receiving waters, DON becomes problematic and needs to be reduced. Biodegradable DON (BDON) is a portion of DON that is biologically degradable by bacteria when the optimum environmental conditions are met. BDON in a two-stage trickling filter WWTP was estimated using artificial intelligence techniques, such as adaptive neuro-fuzzy inference systems, multilayer perceptron, radial basis neural networks (RBNN), and generalized regression neural networks. Nitrite, nitrate, ammonium, TDN, and DON data were used as input neurons. Wastewater samples were collected from four different locations in the plant. Model performances were evaluated using root mean square error, mean absolute error, mean bias error, and coefficient of determination statistics. Modeling results showed that the R(2) values were higher than 0.85 in all four models for all wastewater samples, except only R(2) in the final effluent sample for RBNN modeling was low (0.52). Overall, it was found that all four computing techniques could be employed successfully to predict BDON.

  15. 40 CFR 62.9350 - Identification of plan.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... plan was officially submitted as follows: (1) Control of fluoride emissions from phosphate fertilizer... August 9, 1982. (4) Control of metals, acid gases, organic compounds and nitrogen oxide emissions from..., organic compounds, particulates and nitrogen oxide emissions from existing Hospital/Medical/Infectious...

  16. 78 FR 49701 - Approval and Promulgation of Implementation Plans; Connecticut; Control of Visible Emissions...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-15

    ... power plants and other large stationary sources of air pollution''), 22a-174-22 (``Control of Nitrogen Oxide Emissions''), and 22a-174-22c (``The Clean Air Interstate Rule (CAIR) Nitrogen Oxides (NO X...

  17. Analysis of alternative pathways for reducing nitrogen oxide emissions

    EPA Science Inventory

    Strategies for reducing tropospheric ozone typically include modifying combustion processes to reduce the formation of nitrogen oxides (NOx) and applying control devices that remove NOx from the exhaust gases of power plants, industrial sources and vehicles. For portions of the ...

  18. Aerosol from Organic Nitrogen in the Southeast United States

    EPA Science Inventory

    Biogenic volatile organic compounds (BVOCs) contribute significantly to organic aerosol in the southeastern United States. During the Southern Oxidant and Aerosol Study (SOAS), a portion of ambient organic aerosol was attributed to isoprene oxidation and organic nitrogen from BVO...

  19. Two Catalysts for Selective Oxidation of Contaminant Gases

    NASA Technical Reports Server (NTRS)

    Wright, John D.

    2011-01-01

    Two catalysts for the selective oxidation of trace amounts of contaminant gases in air have been developed for use aboard the International Space Station. These catalysts might also be useful for reducing concentrations of fumes in terrestrial industrial facilities especially facilities that use halocarbons as solvents, refrigerant liquids, and foaming agents, as well as facilities that generate or utilize ammonia. The first catalyst is of the supported-precious-metal type. This catalyst is highly active for the oxidation of halocarbons, hydrocarbons, and oxygenates at low concentrations in air. This catalyst is more active for the oxidation of hydrocarbons and halocarbons than are competing catalysts developed in recent years. This catalyst completely converts these airborne contaminant gases to carbon dioxide, water, and mineral acids that can be easily removed from the air, and does not make any chlorine gas in the process. The catalyst is thermally stable and is not poisoned by chlorine or fluorine atoms produced on its surface during the destruction of a halocarbon. In addition, the catalyst can selectively oxidize ammonia to nitrogen at a temperature between 200 and 260 C, without making nitrogen oxides, which are toxic. The temperature of 260 C is higher than the operational temperature of any other precious-metal catalyst that can selectively oxidize ammonia. The purpose of the platinum in this catalyst is to oxidize hydrocarbons and to ensure that the oxidation of halocarbons goes to completion. However, the platinum exhibits little or no activity for initiating the destruction of halocarbons. Instead, the attack on the halocarbons is initiated by the support. The support also provides a high surface area for exposure of the platinum. Moreover, the support resists deactivation or destruction by halogens released during the destruction of halocarbons. The second catalyst is of the supported- metal-oxide type. This catalyst can selectively oxidize ammonia to nitrogen at temperatures up to 400 C, without producing nitrogen oxides. This catalyst converts ammonia completely to nitrogen, even when the concentration of ammonia is very low. No other catalyst is known to oxidize ammonia selectively at such a high temperature and low concentration. Both the metal oxide and the support contribute to the activity and selectivity of this catalyst.

  20. Treatment of Ammonia Nitrogen Wastewater in Low Concentration by Two-Stage Ozonization

    PubMed Central

    Luo, Xianping; Yan, Qun; Wang, Chunying; Luo, Caigui; Zhou, Nana; Jian, Chensheng

    2015-01-01

    Ammonia nitrogen wastewater (about 100 mg/L) was treated by two-stage ozone oxidation method. The effects of ozone flow rate and initial pH on ammonia removal were studied, and the mechanism of ammonia nitrogen removal by ozone oxidation was discussed. After the primary stage of ozone oxidation, the ammonia removal efficiency reached 59.32% and pH decreased to 6.63 under conditions of 1 L/min ozone flow rate and initial pH 11. Then, the removal efficiency could be over 85% (the left ammonia concentration was lower than 15 mg/L) after the second stage, which means the wastewater could have met the national discharge standards of China. Besides, the mechanism of ammonia removal by ozone oxidation was proposed by detecting the products of the oxidation: ozone oxidation directly and ·OH oxidation; ammonia was mainly transformed into NO3−-N, less into NO2−-N, not into N2. PMID:26404353

  1. Cell signaling by reactive nitrogen and oxygen species in atherosclerosis

    NASA Technical Reports Server (NTRS)

    Patel, R. P.; Moellering, D.; Murphy-Ullrich, J.; Jo, H.; Beckman, J. S.; Darley-Usmar, V. M.

    2000-01-01

    The production of reactive oxygen and nitrogen species has been implicated in atherosclerosis principally as means of damaging low-density lipoprotein that in turn initiates the accumulation of cholesterol in macrophages. The diversity of novel oxidative modifications to lipids and proteins recently identified in atherosclerotic lesions has revealed surprising complexity in the mechanisms of oxidative damage and their potential role in atherosclerosis. Oxidative or nitrosative stress does not completely consume intracellular antioxidants leading to cell death as previously thought. Rather, oxidative and nitrosative stress have a more subtle impact on the atherogenic process by modulating intracellular signaling pathways in vascular tissues to affect inflammatory cell adhesion, migration, proliferation, and differentiation. Furthermore, cellular responses can affect the production of nitric oxide, which in turn can strongly influence the nature of oxidative modifications occurring in atherosclerosis. The dynamic interactions between endogenous low concentrations of oxidants or reactive nitrogen species with intracellular signaling pathways may have a general role in processes affecting wound healing to apoptosis, which can provide novel insights into the pathogenesis of atherosclerosis.

  2. Implications of a More Comprehensive Nitrogen Cycle in a Global Biogeochemical Ocean Model

    NASA Astrophysics Data System (ADS)

    Six, K. D.; Ilyina, T.

    2016-02-01

    Nitrogen plays a crucial role for nearly all living organisms in the Earth system. Changes in the marine nitrogen cycle not only alter the marine biota, but will also have an impact on the marine carbon cycle and, in turn, on climate due to the close coupling of the carbon-nitrogen cycle. The understanding of processes and controls of the marine nitrogen cycle is therefore a prerequisite to reduce uncertainties in the prediction of future climate. Nevertheless, most ocean biogeochemical components of modern Earth system models have a rather simplistic representation of marine N-cycle mainly focusing on nitrate. Here we present results of the HAMburg Ocean Carbon Cycle model (HAMOCC) as part of the MPI-ESM which was extended by a prognostic representation of ammonium and nitrite to resolve important processes of the marine N-cycle such as nitrification and anaerobic ammonium oxidation (anammox). Additionally, we updated the production of nitrous oxide, an important greenhouse gas, allowing for two sources from oxidation of ammonium (nitrification) and from reduction of nitrite (nitrifier-denitrification) at low oxygen concentrations. Besides an extended model data comparison we discuss the following aspects of the N-cycle by model means: (1) contribution of anammox to the loss of fixed nitrogen, and (2) production and emission of marine nitrous oxide.

  3. Effect of zinc oxide nanoparticles on nitrogen removal, microbial activity and microbial community of CANON process in a membrane bioreactor.

    PubMed

    Zhang, Xiaojing; Zhang, Nan; Fu, Haoqiang; Chen, Tao; Liu, Sa; Zheng, Shuhua; Zhang, Jie

    2017-11-01

    In this study, a membrane bioreactor (MBR) was adopted for completely autotrophic nitrogen removal over nitrite (CANON) process. Zinc oxide nanoparticles (ZnO NPs) was step-wise increased to analyze the influence on nitrogen removal, microbial activity and microbial communities. Finally ZnO NPs was removed to study its recovery capability. The bioactivities of ammonia-oxidizing bacteria (AOB), anaerobic ammonia-oxidizing bacteria (AAOB) and nitrite-oxidizing bacteria (NOB) were detected by batch experiments. Results showed that the ZnO NPs with low concentration (≤5mgL -1 ) was profitable for nitrogen removal while the high concentration performed inhibition, and it lowered the abundance of both AOB and NOB while enhanced that of AAOB. ZnO NPs with high concentration (≥10mgL -1 ) suppressed both AOB and AAOB, and long-term exposure within ZnO NPs led to microbial diversity decrease. The inhibition threshold of ZnO NPs on CANON process was 10mgL -1 , and the profitable concentration was 1mgL -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Ammonium conversion and its feedback effect on methane oxidation of Methylosinus sporium.

    PubMed

    He, Ruo; Chen, Min; Ma, Ruo-Chan; Su, Yao; Zhang, Xuan

    2017-04-01

    Ammonium (NH 4 + ) is not only nitrogen source that can support methanotrophic growth, but also it can inhibit methane (CH 4 ) oxidation by competing with CH 4 for the active site of methane monooxygenase. NH 4 + conversion and its feedback effect on the growth and activity of methanotrophs were evaluated with Methylosinus sporium used as a model methanotroph. Nitrogen sources could affect the CH 4 -derived carbon distribution, which varied with incubation time and nitrogen concentrations. More CH 4 -derived carbon was incorporated into biomass in the media with NH 4 + -N, compared to nitrate-nitrogen (NO 3 - -N), as sole nitrogen source at the nitrogen concentrations of 10-18 mmol L -1 . Although ammonia (NH 3 ) oxidation activity of methanotrophs was considerably lower, only accounting for 0.01-0.06% of CH 4 oxidation activity in the experimental cultures, NH 4 + conversion could lead to the pH decrease and toxic intermediates accumulation in the their habits. Compared with NH 4 + , nitrite (NO 2 - ) accumulation in the NH 4 + conversion of methanotroph had stronger inhibition on its activity, especially the joint inhibition of NO 2 - accumulation and the pH decrease during the NH 4 + -N conversion. These results suggested that more attention should be paid to the feedback effects of NH 4 + conversion by methanotrophs to understand effects of NH 4 + on CH 4 oxidation in the environments. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  5. The effect of processing conditions on the GaAs/plasma-grown insulator interface

    NASA Technical Reports Server (NTRS)

    Hshieh, F. I.; Borrego, J. M.; Ghandhi, S. K.

    1986-01-01

    The effect of processing conditions on the interface state density was evaluated from C-V measurements on metal-oxide-semiconductor capacitors. The optimum processing conditions for the minimum surface state density was found to be related to the postoxidation annealing temperature and time, and was independent of chemical treatments prior to oxidation. Annealing at the optimum condition (i.e., at 350 C for 1 h in either nitrogen or hydrogen gas, with or without an aluminum pattern on the oxide) reduces the fast surface state density by about one order of magnitude. By using a nitrogen/oxygen plasma, the static dielectric constant of the oxide decreased as the N/O ratio was increased, and nitrogen was incorporated into the oxide. In addition, the fast surface state density was reduced as a result of this nitridation process.

  6. Advanced dry head-end reprocessing of light water reactor spent nuclear fuel

    DOEpatents

    Collins, Emory D; Delcul, Guillermo D; Hunt, Rodney D; Johnson, Jared A; Spencer, Barry B

    2013-11-05

    A method for reprocessing spent nuclear fuel from a light water reactor includes the step of reacting spent nuclear fuel in a voloxidation vessel with an oxidizing gas having nitrogen dioxide and oxygen for a period sufficient to generate a solid oxidation product of the spent nuclear fuel. The reacting step includes the step of reacting, in a first zone of the voloxidation vessel, spent nuclear fuel with the oxidizing gas at a temperature ranging from 200-450.degree. C. to form an oxidized reaction product, and regenerating nitrogen dioxide, in a second zone of the voloxidation vessel, by reacting oxidizing gas comprising nitrogen monoxide and oxygen at a temperature ranging from 0-80.degree. C. The first zone and the second zone can be separate. A voloxidation system is also disclosed.

  7. Advanced dry head-end reprocessing of light water reactor spent nuclear fuel

    DOEpatents

    Collins, Emory D.; Delcul, Guillermo D.; Hunt, Rodney D.; Johnson, Jared A.; Spencer, Barry B.

    2014-06-10

    A method for reprocessing spent nuclear fuel from a light water reactor includes the step of reacting spent nuclear fuel in a voloxidation vessel with an oxidizing gas having nitrogen dioxide and oxygen for a period sufficient to generate a solid oxidation product of the spent nuclear fuel. The reacting step includes the step of reacting, in a first zone of the voloxidation vessel, spent nuclear fuel with the oxidizing gas at a temperature ranging from 200-450.degree. C. to form an oxidized reaction product, and regenerating nitrogen dioxide, in a second zone of the voloxidation vessel, by reacting oxidizing gas comprising nitrogen monoxide and oxygen at a temperature ranging from 0-80.degree. C. The first zone and the second zone can be separate. A voloxidation system is also disclosed.

  8. Hexacoordinated nitrogen(V) stabilized by high pressure

    PubMed Central

    Kurzydłowski, Dominik; Zaleski-Ejgierd, Patryk

    2016-01-01

    In all of its known connections nitrogen retains a valence shell electron count of eight therefore satisfying the golden rule of chemistry - the octet rule. Despite the diversity of nitrogen chemistry (with oxidation states ranging from + 5 to −3), and despite numerous efforts, compounds containing nitrogen with a higher electron count (hypervalent nitrogen) remain elusive and are yet to be synthesized. One possible route leading to nitrogen’s hypervalency is the formation of a chemical moiety containing pentavalent nitrogen atoms coordinated by more than four substituents. Here, we present theoretical evidence that a salt containing hexacoordinated nitrogen(V), in the form of an NF6− anion, could be synthesized at a modest pressure of 40 GPa (=400 kbar) via spontaneous oxidation of NF3 by F2. Our results indicate that the synthesis of a new class of compounds containing hypervalent nitrogen is within reach of current high-pressure experimental techniques. PMID:27808104

  9. Material and system for catalytic reduction of nitrogen oxide in an exhaust stream of a combustion process

    DOEpatents

    Gardner, Timothy J.; Lott, Stephen E.; Lockwood, Steven J.; McLaughlin, Linda I.

    1998-01-01

    A catalytic material of activated hydrous metal oxide doped with platinum, palladium, or a combination of these, and optionally containing an alkali or alkaline earth metal, that is effective for NO.sub.X reduction in an oxidizing exhaust stream from a combustion process is disclosed. A device for reduction of nitrogen oxides in an exhaust stream, particularly an automotive exhaust stream, the device having a substrate coated with the activated noble-metal doped hydrous metal oxide of the invention is also provided.

  10. Nitrogen dioxide produced by self-sustained pyrolysis of nitrous oxide

    NASA Technical Reports Server (NTRS)

    Sabol, A. P.

    1965-01-01

    Apparatus is developed for achieving continuous self-sustaining pyrolysis reaction in the production of nitrogen dioxide from nitrous oxide. The process becomes self-sustaining because of the exothermic reaction and the regenerative heating of the gases in the pyrolysis chamber.

  11. Air Quality Criteria for Oxides of Nitrogen (Final Report, 1982)

    EPA Science Inventory

    This document is an evaluation and assessment of scientific information relative to determining the health and welfare effects associated with exposure to various concentrations of nitrogen oxides in ambient air. The document is not intended as a complete, detailed literature rev...

  12. CONTROLLING NITROGEN OXIDES

    EPA Science Inventory

    Recent research indicates that nitrogen oxides (NOx) could be one of the most troublesome air pollutants of the 1980's. More than 20 million metric tons of NOx are annually polluting our air as a result of the widespread combustion of fossil fuels in power plants, industrial boil...

  13. An analytical study of nitrogen oxides and carbon monoxide emissions in hydrocarbon combustion with added nitrogen - Preliminary results

    NASA Technical Reports Server (NTRS)

    Bittker, D. A.

    1980-01-01

    The influence of ground-based gas turbine combustor operating conditions and fuel-bound nitrogen (FBN) found in coal-derived liquid fuels on the formation of nitrogen oxides and carbon monoxide is investigated. Analytical predictions of NOx and CO concentrations are obtained for a two-stage, adiabatic, perfectly-stirred reactor operating on a propane-air mixture, with primary equivalence ratios from 0.5 to 1.7, secondary equivalence ratios of 0.5 or 0.7, primary stage residence times from 12 to 20 msec, secondary stage residence times of 1, 2 and 3 msec and fuel nitrogen contents of 0.5, 1.0 and 2.0 wt %. Minimum nitrogen oxide but maximum carbon monoxide formation is obtained at primary zone equivalence ratios between 1.4 and 1.5, with percentage conversion of FBN to NOx decreasing with increased fuel nitrogen content. Additional secondary dilution is observed to reduce final pollutant concentrations, with NOx concentration independent of secondary residence time and CO decreasing with secondary residence time; primary zone residence time is not observed to affect final NOx and CO concentrations significantly. Finally, comparison of computed results with experimental values shows a good semiquantitative agreement.

  14. Surface oxidation of GaN(0001): Nitrogen plasma-assisted cleaning for ultrahigh vacuum applications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gangopadhyay, Subhashis; Schmidt, Thomas, E-mail: tschmidt@ifp.uni-bremen.de; Kruse, Carsten

    The cleaning of metal-organic vapor-phase epitaxial GaN(0001) template layers grown on sapphire has been investigated. Different procedures, performed under ultrahigh vacuum conditions, including degassing and exposure to active nitrogen from a radio frequency nitrogen plasma source have been compared. For this purpose, x-ray photoelectron spectroscopy, reflection high-energy electron diffraction, and scanning tunneling microscopy have been employed in order to assess chemical as well as structural and morphological surface properties. Initial degassing at 600 °C under ultrahigh vacuum conditions only partially eliminates the surface contaminants. In contrast to plasma assisted nitrogen cleaning at temperatures as low as 300 °C, active-nitrogen exposure at temperaturesmore » as high as 700 °C removes the majority of oxide species from the surface. However, extended high-temperature active-nitrogen cleaning leads to severe surface roughening. Optimum results regarding both the removal of surface oxides as well as the surface structural and morphological quality have been achieved for a combination of initial low-temperature plasma-assisted cleaning, followed by a rapid nitrogen plasma-assisted cleaning at high temperature.« less

  15. Supercapacitors based on nitrogen-doped reduced graphene oxide and borocarbonitrides

    NASA Astrophysics Data System (ADS)

    Gopalakrishnan, K.; Moses, Kota; Govindaraj, A.; Rao, C. N. R.

    2013-12-01

    Nitrogen-doped reduced graphene oxide (RGO) samples with different nitrogen content, prepared by two different methods, as well as nitrogen-doped few-layer graphene have been investigated as supercapacitor electrodes. Two electrode measurements have been carried out both in aqueous (6M KOH) and in ionic liquid media. Nitrogen-doped reduced graphene oxides exhibit satisfactory specific capacitance, the values reaching 126F/g at a scan rate of 10mV/s in aqueous medium. Besides providing supercapacitor characteristics, the study has shown the nitrogen content and surface area to be important factors. High surface-area borocarbonitrides, BxCyNz, prepared by the urea route appear to be excellent supercapacitor electrode materials. Thus, BC4.5N exhibits a specific capacitance of 169F/g at a scan rate of 10mV/s in aqueous medium. In an ionic liquid medium, nitrogen-doped RGO and BC4.5N exhibit specific capacitance values of 258F/g and 240F/g at a scan rate of 5mV/s. The ionic liquid enables a larger operating voltage range of 0.0-2.5V compared to 0.0-1V in aqueous medium.

  16. Chemical Modification of Graphene Oxide by Nitrogenation: An X-ray Absorption and Emission Spectroscopy Study

    DOE PAGES

    Chuang, Cheng-Hao; Ray, Sekhar C.; Mazumder, Debarati; ...

    2017-02-10

    Nitrogen-doped graphene oxides (GO:N x) were synthesized by a partial reduction of graphene oxide (GO) using urea [CO(NH 2) 2 ]. Their electronic/bonding structures were investigated using X-ray absorption near-edge structure (XANES), valence-band photoemission spectroscopy (VB-PES), X-ray emission spectroscopy (XES) and resonant inelastic X-ray scattering (RIXS). During GO:N x synthesis, different nitrogen-bonding species, such as pyrrolic/graphitic-nitrogen, were formed by replacing of oxygen-containing functional groups. At lower N-content (2.7 at%), pyrrolic-N, owing to surface and subsurface diffusion of C, N and NH is deduced from various X-ray spectroscopies. In contrast, at higher N-content (5.0 at%) graphitic nitrogen was formed in whichmore » each N-atom trigonally bonds to three distinct sp 2 -hybridized carbons with substitution of the N-atoms for C atoms in the graphite layer. Upon nitrogen substitution, the total density of state close to Fermi level is increased to raise the valence-band maximum, as revealed by VB-PES spectra, indicating an electron donation from nitrogen, molecular bonding C/N/O coordination or/and lattice structure reorganization in GO:N x . The well-ordered chemical environments induced by nitrogen dopant are revealed by XANES and RIXS measurements.« less

  17. Chemical Modification of Graphene Oxide by Nitrogenation: An X-ray Absorption and Emission Spectroscopy Study

    NASA Astrophysics Data System (ADS)

    Chuang, Cheng-Hao; Ray, Sekhar C.; Mazumder, Debarati; Sharma, Surbhi; Ganguly, Abhijit; Papakonstantinou, Pagona; Chiou, Jau-Wern; Tsai, Huang-Ming; Shiu, Hung-Wei; Chen, Chia-Hao; Lin, Hong-Ji; Guo, Jinghua; Pong, Way-Faung

    2017-02-01

    Nitrogen-doped graphene oxides (GO:Nx) were synthesized by a partial reduction of graphene oxide (GO) using urea [CO(NH2)2]. Their electronic/bonding structures were investigated using X-ray absorption near-edge structure (XANES), valence-band photoemission spectroscopy (VB-PES), X-ray emission spectroscopy (XES) and resonant inelastic X-ray scattering (RIXS). During GO:Nx synthesis, different nitrogen-bonding species, such as pyrrolic/graphitic-nitrogen, were formed by replacing of oxygen-containing functional groups. At lower N-content (2.7 at%), pyrrolic-N, owing to surface and subsurface diffusion of C, N and NH is deduced from various X-ray spectroscopies. In contrast, at higher N-content (5.0 at%) graphitic nitrogen was formed in which each N-atom trigonally bonds to three distinct sp2-hybridized carbons with substitution of the N-atoms for C atoms in the graphite layer. Upon nitrogen substitution, the total density of state close to Fermi level is increased to raise the valence-band maximum, as revealed by VB-PES spectra, indicating an electron donation from nitrogen, molecular bonding C/N/O coordination or/and lattice structure reorganization in GO:Nx. The well-ordered chemical environments induced by nitrogen dopant are revealed by XANES and RIXS measurements.

  18. Anaerobic ammonium oxidation and its contribution to nitrogen removal in China’s coastal wetlands

    NASA Astrophysics Data System (ADS)

    Hou, Lijun; Zheng, Yanling; Liu, Min; Li, Xiaofei; Lin, Xianbiao; Yin, Guoyu; Gao, Juan; Deng, Fengyu; Chen, Fei; Jiang, Xiaofen

    2015-10-01

    Over the past several decades, human activities have caused substantial enrichment of reactive nitrogen in China’s coastal wetlands. Although anaerobic ammonium oxidation (anammox), the process of oxidizing ammonium into dinitrogen gas through the reduction of nitrite, is identified as an important process for removing reactive nitrogen, little is known about the dynamics of anammox and its contribution to nitrogen removal in nitrogen-enriched environments. Here, we examine potential rates of anammox and associate them with bacterial diversity and abundance across the coastal wetlands of China using molecular and isotope tracing techniques. High anammox bacterial diversity was detected in China’s coastal wetlands and included Candidatus Scalindua, Kuenenia, Brocadia, and Jettenia. Potential anammox rates were more closely associated with the abundance of anammox bacteria than to their diversity. Among all measured environmental variables, temperature was a key environmental factor, causing a latitudinal distribution of the anammox bacterial community composition, biodiversity and activity along the coastal wetlands of China. Based on nitrogen isotope tracing experiments, anammox was estimated to account for approximately 3.8-10.7% of the total reactive nitrogen removal in the study area. Combined with denitrification, anammox can remove 20.7% of the total external terrigenous inorganic nitrogen annually transported into China’s coastal wetland ecosystems.

  19. Anaerobic Ammonium Oxidation and its Contribution to Nitrogen Removal in China's Coastal Wetlands

    NASA Astrophysics Data System (ADS)

    Hou, L., Sr.

    2016-02-01

    Over the past several decades, human activities have caused substantial enrichment of reactive nitrogen in China's coastal wetlands. Although anaerobic ammonium oxidation (anammox), the process of oxidizing ammonium into dinitrogen gas through the reduction of nitrite, is identified as an important process for removing reactive nitrogen, little is known about the dynamics of anammox and its contribution to nitrogen removal in nitrogen-enriched environments. Here, we examine potential rates of anammox and associate them with bacterial diversity and abundance across the coastal wetlands of China using molecular and isotope tracing techniques. High anammox bacterial diversity was detected in China's coastal wetlands and included Candidatus Scalindua, Kuenenia, Brocadia, and Jettenia. Potential anammox rates were more closely associated with the abundance of anammox bacteria than to their diversity. Among all measured environmental variables, temperature was a key environmental factor, causing a latitudinal distribution of the anammox bacterial community composition, biodiversity and activity along the coastal wetlands of China. Based on nitrogen isotope tracing experiments, anammox was estimated to account for approximately 3.8-10.7% of the total reactive nitrogen removal in the study area. Combined with denitrification, anammox can remove 20.7% of the total external terrigenous inorganic nitrogen annually transported into China's coastal wetland ecosystems.

  20. Anaerobic ammonium oxidation and its contribution to nitrogen removal in China’s coastal wetlands

    PubMed Central

    Hou, Lijun; Zheng, Yanling; Liu, Min; Li, Xiaofei; Lin, Xianbiao; Yin, Guoyu; Gao, Juan; Deng, Fengyu; Chen, Fei; Jiang, Xiaofen

    2015-01-01

    Over the past several decades, human activities have caused substantial enrichment of reactive nitrogen in China’s coastal wetlands. Although anaerobic ammonium oxidation (anammox), the process of oxidizing ammonium into dinitrogen gas through the reduction of nitrite, is identified as an important process for removing reactive nitrogen, little is known about the dynamics of anammox and its contribution to nitrogen removal in nitrogen-enriched environments. Here, we examine potential rates of anammox and associate them with bacterial diversity and abundance across the coastal wetlands of China using molecular and isotope tracing techniques. High anammox bacterial diversity was detected in China’s coastal wetlands and included Candidatus Scalindua, Kuenenia, Brocadia, and Jettenia. Potential anammox rates were more closely associated with the abundance of anammox bacteria than to their diversity. Among all measured environmental variables, temperature was a key environmental factor, causing a latitudinal distribution of the anammox bacterial community composition, biodiversity and activity along the coastal wetlands of China. Based on nitrogen isotope tracing experiments, anammox was estimated to account for approximately 3.8–10.7% of the total reactive nitrogen removal in the study area. Combined with denitrification, anammox can remove 20.7% of the total external terrigenous inorganic nitrogen annually transported into China’s coastal wetland ecosystems. PMID:26494435

  1. 40 CFR 52.2620 - Identification of plan.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... standards for nitrogen oxides 9/13/99, 10/29/99 7/28/04, 69 FR 44965. Section 4 Ambient standards for sulfur... nitrogen oxides 9/13/99, 10/29/99 7/28/04, 69 FR 44965. Section 4 Emission standards for sulfur oxides 9/13... 7/28/04, 69 FR 44965. Chapter 4 Section 2 Existing sulfuric acid production units 9/13/99, 10/29/99...

  2. SBAR Panel: Phase I Federal Implementation Plans (FIPs) To Reduce the Regional Transport of Ozone in the Eastern United States

    EPA Pesticide Factsheets

    SBAR panel on regional reductions of nitrogen oxides, with focus on the windborne transport of ozone smog and nitrogen oxides from NOx-producing sources in 22 eastern states and the District of Columbia

  3. 40 CFR 91.203 - General provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... hydrocarbon plus oxides of nitrogen emissions from eligible marine SI engines are described in this subpart... provisions for hydrocarbon plus oxides of nitrogen emissions if it is subject to regulation under subpart B... applicable emission standard, provided the summation of the manufacturer's projected balance of all credit...

  4. 40 CFR 91.203 - General provisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... hydrocarbon plus oxides of nitrogen emissions from eligible marine SI engines are described in this subpart... provisions for hydrocarbon plus oxides of nitrogen emissions if it is subject to regulation under subpart B... applicable emission standard, provided the summation of the manufacturer's projected balance of all credit...

  5. 40 CFR 91.203 - General provisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... hydrocarbon plus oxides of nitrogen emissions from eligible marine SI engines are described in this subpart... provisions for hydrocarbon plus oxides of nitrogen emissions if it is subject to regulation under subpart B... applicable emission standard, provided the summation of the manufacturer's projected balance of all credit...

  6. 40 CFR 91.203 - General provisions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... hydrocarbon plus oxides of nitrogen emissions from eligible marine SI engines are described in this subpart... provisions for hydrocarbon plus oxides of nitrogen emissions if it is subject to regulation under subpart B... applicable emission standard, provided the summation of the manufacturer's projected balance of all credit...

  7. 40 CFR 91.203 - General provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... hydrocarbon plus oxides of nitrogen emissions from eligible marine SI engines are described in this subpart... provisions for hydrocarbon plus oxides of nitrogen emissions if it is subject to regulation under subpart B... applicable emission standard, provided the summation of the manufacturer's projected balance of all credit...

  8. 40 CFR 86.1327-96 - Engine dynamometer test procedures; overview.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... hydrocarbons, carbon monoxide, oxides of nitrogen, particulate, methanol and formaldehyde, as applicable. The... either in bags or continuously for hydrocarbons (HC), methane (CH4) carbon monoxide (CO), carbon dioxide... levels of hydrocarbon, carbon monoxide, carbon dioxide, and oxides of nitrogen and, if appropriate...

  9. 40 CFR 86.1327-96 - Engine dynamometer test procedures; overview.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... hydrocarbons, carbon monoxide, oxides of nitrogen, particulate, methanol and formaldehyde, as applicable. The... either in bags or continuously for hydrocarbons (HC), methane (CH4) carbon monoxide (CO), carbon dioxide... levels of hydrocarbon, carbon monoxide, carbon dioxide, and oxides of nitrogen and, if appropriate...

  10. One - Step synthesis of nitrogen doped reduced graphene oxide with NiCo nanoparticles for ethanol oxidation in alkaline media.

    PubMed

    Kakaei, Karim; Marzang, Kamaran

    2016-01-15

    Development of anode catalysts and catalyst supporting carbonaceous material containing non-precious metal have attracted tremendous attention in the field of direct ethanol fuel cells (DEFCs). Herein, we report the synthesis and electrochemical properties of nitrogen-doped reduced graphene oxide (NRGO) supported Co, Ni and NiCo nanocomposites. The metal NRGO nanocomposites, in which metal nanoparticles are embedded in the highly porous nitrogen-doped graphene matrix, have been synthesized by simply and one-pot method at a mild temperature using GO, urea choline chloride and urea as reducing and doping agent. The fabricated NiCo/NRGO exhibit remarkable electrocatalytic activity (with Tafel slope of 159.1mVdec(-1)) and high stability for the ethanol oxidation reaction (EOR). The superior performance of the alloy based NRGO is attributed to high surface area, well uniform distribution of high-density nitrogen, metal active sites and synergistic effect. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Effects of pyrolysis temperature, time and leaf litter and powder coal ash addition on sludge-derived adsorbents for nitrogen oxide.

    PubMed

    Ren, Xiaoli; Liang, Baohong; Liu, Min; Xu, Xiaoyuan; Cui, Meihua

    2012-12-01

    The objective of this research was to seek a cost effective solution to prepare adsorbents for nitrogen oxide from surplus sludge. Leaf litter and powder coal ash were used as cheap and easily available additives. An adsorbent for nitrogen oxide was prepared by pyrolysis of dried sludge mixed with zinc chloride. Under optimum pyrolysis conditions of 375°C for 90 min and a zinc chloride content of 30%, the surface area of the adsorbent with leaf litter was 514.41 m(2)/g, the surface area of the adsorbent with powder coal ash was 432.34 m(2)/g, respectively, corresponding to an increase of 90.70% and 60.27% when compared to the adsorbent without the additives. The saturated adsorption quantity of the adsorbent with leaf litter reached 271 mg/g at 20°C. The results indicated that the sludge-derived adsorbent was quite promising for nitrogen oxide removal. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Spectrophotometric Determination of Nitrogen Oxides in the Air with 2-N-Ethyl-5-Naphthol-7-Sulfonic Acid

    NASA Astrophysics Data System (ADS)

    Huang, Y.; Shi, W.; Zhang, C.; Wen, H.

    2017-09-01

    For the determination of nitrogen oxides in the air, the structure of diazo and coupling compounds was studied and tested by experiments. The conditions and methods of diazo and coupling reactions were investigated. Furthermore, a spectrophotometric method using sulfanilamide as a diazo compound and 2-N-ethyl-5-naphthol-7-sulfonic acid (N-ethyl J acid) as a coupling compound was proposed. The maximum absorption wavelength of sulfanilamide-Nethyl J acid azo compound was at 478 nm. The molar absorptivity was 4.31 × 104 L/(mol × cm) with a recovery of 98.7-100.9% and RSD of 1.85%. For nitrogen oxides, the determinate limit of this measurement was 0.015 mg/m3 and the determinate range 0.024-2.0 mg/m3. Moreover, a high degree of correlation was observed between the results obtained by the proposed method and the standard methods. The proposed method can be easily applied to determine nitrogen oxides in the air.

  13. Louisiana SIP: LAC 33:III Ch. 7 Section 709. Measurement of Concentrations PM10, SO2, Carbon Monoxide, Atmospheric Oxidants, Nitrogen Oxides, and Lead; SIP effective 1989-05-08 (LAc49) and 1989-08-14 (LAc50) to 2011-08-03 (LAd34 - Revised)

    EPA Pesticide Factsheets

    Louisiana SIP: LAC 33:III Ch. 7 Section 709. Measurement of Concentrations PM10, SO2, Carbon Monoxide, Atmospheric Oxidants, Nitrogen Oxides, and Lead; SIP effective 1989-05-08 (LAc49) and 1989-08-14 (LAc50) to 2011-08-03 (LAd34 - Revised)

  14. [Microbial ecology of archaeal ammonia oxidation--a review].

    PubMed

    Jia, Zhongjun; Weng, Jiahua; Lin, Xiangui; Conrad, Ralf

    2010-04-01

    Bacteria have long been considered as the key driver of ammonia oxidation on earth. This concept has been challenged recently by the discovery of chemolithoautotrophic isolate of ammonia-oxidizing archaeon in marine. The relative contribution of bacteria and archaea to ammonia oxidation is essential for our understanding of global nitrogen cycle. Recent study suggested a key role of archaeal ammonia oxidation in the marine nitrogen cycle. Our work however revealed the predominace of bacterial ammonia oxidation in agricultural soil. From the biogeochemical perspective, here we summarized the discovery, progress and prospect of archaeal ammonia oxidation. Of great interest in the future would be to elucidate the metabolisms of ammonia-oxidizing archaeon in natural environment and the underlying mechanism that leads to the physiological divergence of ammonia oxidizers.

  15. Global Rsh-dependent transcription profile of Brucella suis during stringent response unravels adaptation to nutrient starvation and cross-talk with other stress responses

    PubMed Central

    2013-01-01

    Background In the intracellular pathogen Brucella spp., the activation of the stringent response, a global regulatory network providing rapid adaptation to growth-affecting stress conditions such as nutrient deficiency, is essential for replication in the host. A single, bi-functional enzyme Rsh catalyzes synthesis and hydrolysis of the alarmone (p)ppGpp, responsible for differential gene expression under stringent conditions. Results cDNA microarray analysis allowed characterization of the transcriptional profiles of the B. suis 1330 wild-type and Δrsh mutant in a minimal medium, partially mimicking the nutrient-poor intramacrophagic environment. A total of 379 genes (11.6% of the genome) were differentially expressed in a rsh-dependent manner, of which 198 were up-, and 181 were down-regulated. The pleiotropic character of the response was confirmed, as the genes encoded an important number of transcriptional regulators, cell envelope proteins, stress factors, transport systems, and energy metabolism proteins. Virulence genes such as narG and sodC, respectively encoding respiratory nitrate reductase and superoxide dismutase, were under the positive control of (p)ppGpp, as well as expression of the cbb3-type cytochrome c oxidase, essential for chronic murine infection. Methionine was the only amino acid whose biosynthesis was absolutely dependent on stringent response in B. suis. Conclusions The study illustrated the complexity of the processes involved in adaptation to nutrient starvation, and contributed to a better understanding of the correlation between stringent response and Brucella virulence. Most interestingly, it clearly indicated (p)ppGpp-dependent cross-talk between at least three stress responses playing a central role in Brucella adaptation to the host: nutrient, oxidative, and low-oxygen stress. PMID:23834488

  16. Impact of aerobic acclimation on the nitrification performance and microbial community of landfill leachate sludge.

    PubMed

    Hira, Daisuke; Aiko, Nobuyuki; Yabuki, Yoshinori; Fujii, Takao

    2018-03-01

    Nitrogenous pollution of water is regarded as a global environmental problem, and nitrogen removal has become an important issue in wastewater treatment processes. Landfill leachate is a typical large source of nitrogenous wastewater. Although the characteristics of leachate vary according to the age of the landfill, leachates of mature landfill have high concentrations of nitrogenous compounds. Most nitrogen in these leachates is in the form of ammonium nitrogen. In this study, we investigated the bacterial community of sludge from a landfill leachate lagoon by pyrosequencing of the bacterial 16S rRNA gene. The sludge was acclimated in a laboratory-scale reactor with aeration using a mechanical stirrer to promote nitrification. On 149 days, nitrification was achieved and then the bacterial community was also analyzed. The bacterial community was also analyzed after nitrification was achieved. Pyrosequencing analyses revealed that the abundances of ammonia-oxidizing and nitrite-oxidizing bacteria were increased by acclimation and their total proportions increased to >15% of total biomass. Changes in the sulfate-reducing and sulfur-oxidizing bacteria were also observed during the acclimation process. The aerobic acclimation process enriched a nitrifying microbial community from the landfill leachate sludge. These results suggested that the aerobic acclimation is a processing method for the nitrification ammonium oxidizing throw the enrichment of nitrifiers. Improvement of this acclimation method would allow nitrogen removal from leachate by nitrification and sulfur denitrification. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Emission Projections for Long-Haul Freight Trucks and Rail in the United States through 2050.

    PubMed

    Liu, Liang; Hwang, Taesung; Lee, Sungwon; Ouyang, Yanfeng; Lee, Bumsoo; Smith, Steven J; Yan, Fang; Daenzer, Kathryn; Bond, Tami C

    2015-10-06

    This work develops an integrated model approach for estimating emissions from long-haul freight truck and rail transport in the United States between 2010 and 2050. We connect models of macroeconomic activity, freight demand by commodity, transportation networks, and emission technology to represent different pathways of future freight emissions. Emissions of particulate matter (PM), carbon monoxide (CO), nitrogen oxides (NOx), and total hydrocarbon (THC) decrease by 60%-70% from 2010 to 2030, as older vehicles built to less-stringent emission standards retire. Climate policy, in the form of carbon tax that increases apparent fuel prices, causes a shift from truck to rail, resulting in a 30% reduction in fuel consumption and a 10%-28% reduction in pollutant emissions by 2050, if rail capacity is sufficient. Eliminating high-emitting conditions in the truck fleet affects air pollutants by 20% to 65%; although these estimates are highly uncertain, they indicate the importance of durability in vehicle engines and emission control systems. Future infrastructure investment will be required both to meet transport demand and to enable actions that reduce emissions of air and climate pollutants. By driving the integrated model framework with two macroeconomic scenarios, we show that the effect of carbon tax on air pollution is robust regardless of growth levels.

  18. Chronic obstructive pulmonary diseases related to outdoor PM10, O3, SO2, and NO2 in a heavily polluted megacity of Iran.

    PubMed

    Khaniabadi, Yusef Omidi; Daryanoosh, Mohammad; Sicard, Pierre; Takdastan, Afshin; Hopke, Philip K; Esmaeili, Shirin; De Marco, Alessandra; Rashidi, Rajab

    2018-04-18

    This study was conducted to quantify, by an approach proposed by the World Health Organization (WHO), the daily hospital admissions for chronic obstructive pulmonary disease (COPD) related to exposure to particulate matter (PM 10 ) and oxidants such as ozone (O 3 ), sulfur dioxide (SO 2 ), and nitrogen dioxide (NO 2 ) in a heavily polluted city in Iran. For the health impact assessment, in terms of COPD, the current published relative risk (RR) and baseline incidence (BI) values, suggested by the WHO, and the 1-h O 3 concentrations and daily PM 10 , NO 2 , and SO 2 concentrations were compiled. The results showed that 5.9, 4.1, 1.2, and 1.9% of the COPD daily hospitalizations in 2011 and 6.6, 1.9, 2.3, and 2.1% in 2012 were attributed to PM 10 , O 3 , SO 2 , and NO 2 concentrations exceeding 10 μg/m 3 , respectively. This study indicates that air quality and the high air pollutant levels have an effect on COPD morbidity. Air pollution is associated with visits to emergency services and hospital admissions. A lower relative risk can be achieved if some stringent control strategies for reducing air pollutants or emission precursors are implemented.

  19. Modeling Ozone in the Eastern U.S. using a Fuel-Based Mobile Source Emissions Inventory.

    PubMed

    McDonald, Brian C; McKeen, Stuart A; Cui, Yu Yan; Ahmadov, Ravan; Kim, Si-Wan; Frost, Gregory J; Pollack, Ilana B; Peischl, Jeff; Ryerson, Thomas B; Holloway, John S; Graus, Martin; Warneke, Carsten; Gilman, Jessica B; de Gouw, Joost A; Kaiser, Jennifer; Keutsch, Frank N; Hanisco, Thomas F; Wolfe, Glenn M; Trainer, Michael

    2018-06-22

    Recent studies suggest overestimates in current U.S. emission inventories of nitrogen oxides (NO x = NO + NO 2 ). Here, we expand a previously developed fuel-based inventory of motor-vehicle emissions (FIVE) to the continental U.S. for the year 2013, and evaluate our estimates of mobile source emissions with the U.S. Environmental Protection Agency's National Emissions Inventory (NEI) interpolated to 2013. We find that mobile source emissions of NO x and carbon monoxide (CO) in the NEI are higher than FIVE by 28% and 90%, respectively. Using a chemical transport model, we model mobile source emissions from FIVE, and find consistent levels of urban NO x and CO as measured during the Southeast Nexus (SENEX) Study in 2013. Lastly, we assess the sensitivity of ozone (O 3 ) over the Eastern U.S. to uncertainties in mobile source NO x emissions and biogenic volatile organic compound (VOC) emissions. The ground-level O 3 is sensitive to reductions in mobile source NO x emissions, most notably in the Southeastern U.S. and during O 3 exceedance events, under the revised standard proposed in 2015 (>70 ppb, 8 h maximum). This suggests that decreasing mobile source NO x emissions could help in meeting more stringent O 3 standards in the future.

  20. [Bacterial anaerobic ammonia oxidation (Anammox) in the marine nitrogen cycle--a review].

    PubMed

    Hong, Yiguo; Li, Meng; Gu, Jidong

    2009-03-01

    Anaerobic ammonium oxidation (Anammox) is a microbial oxidation process of ammonium, with nitrite as the electron acceptor and dinitrogen gas as the main product, and is performed by a clade of deeply branched Planctomycetes, which possess an intracytoplasmic membrane-bounded organelle, the anammoxosome, for the Anammox process. The wide distribution of Anammox bacteria in different natural environments has been greatly modified the traditional view of biogeochemical cycling of nitrogen, in which microbial denitrifier is considered as the only organism to respire nitrate and nitrite to produce nitric and nitrous oxides, and eventually nitrogen gas. More evidences indicate that Anammox is responsible for the production of more than 50% of oceanic N2 and plays an important role in global nitrogen cycling. Moreover, due to the close relationship between nitrogen and carbon cycling, it is anticipated that Anammox process might also affect the concentration of CO2 in the atmosphere, and influence the global climate change. In addition, the simultaneous transformation of nitrite and ammonium in wastewater treatment by Anammox would allow a 90% reduction in operational costs and provide a much more effective biotechnological process for wastewater treatment.

  1. A case study of the relative effects of power plant nitrogen oxides and sulfur dioxide emission reductions on atmospheric nitrogen deposition.

    PubMed

    Vijayaraghavan, Krish; Seigneur, Christian; Bronson, Rochelle; Chen, Shu-Yun; Karamchandani, Prakash; Walters, Justin T; Jansen, John J; Brandmeyer, Jo Ellen; Knipping, Eladio M

    2010-03-01

    The contrasting effects of point source nitrogen oxides (NOx) and sulfur dioxide (SO2) air emission reductions on regional atmospheric nitrogen deposition are analyzed for the case study of a coal-fired power plant in the southeastern United States. The effect of potential emission reductions at the plant on nitrogen deposition to Escambia Bay and its watershed on the Florida-Alabama border is simulated using the three-dimensional Eulerian Community Multiscale Air Quality (CMAQ) model. A method to quantify the relative and individual effects of NOx versus SO2 controls on nitrogen deposition using air quality modeling results obtained from the simultaneous application of NOx and SO2 emission controls is presented and discussed using the results from CMAQ simulations conducted with NOx-only and SO2-only emission reductions; the method applies only to cases in which ambient inorganic nitrate is present mostly in the gas phase; that is, in the form of gaseous nitric acid (HNO3). In such instances, the individual effects of NOx and SO2 controls on nitrogen deposition can be approximated by the effects of combined NOx + SO2 controls on the deposition of NOy, (the sum of oxidized nitrogen species) and reduced nitrogen species (NHx), respectively. The benefit of controls at the plant in terms of the decrease in nitrogen deposition to Escambia Bay and watershed is less than 6% of the overall benefit due to regional Clean Air Interstate Rule (CAIR) controls.

  2. Nitrogen removal from wastewater by a catalytic oxidation method.

    PubMed

    Huang, T L; Macinnes, J M; Cliffe, K R

    2001-06-01

    The ammonia-containing waste produced in industries is usually characterized by high concentration and high temperature, and is not treatable by biological methods directly. In this study, a hydrophobic Pt/SDB catalyst was first used in a trickle-bed reactor to remove ammonia from wastewater. In the reactor, both stripping and catalytic oxidation occur simultaneously. It was found that higher temperature and higher oxygen partial pressure enhanced the ammonia removal. A reaction pathway, which involves oxidizing ammonia to nitric oxide, which then further reacts with ammonia to produce nitrogen and water, was confirmed. Small amounts of by-products, nitrites and nitrates were also detected in the resultant reaction solution. These compounds came from the absorption of nitrogen oxides. Both the minimum NO2- selectivity and maximum ammonia removal were achieved when the resultant pH of treated water was near 7.5 for a feed of unbuffered ammonia solution.

  3. Anodic Behaviour of High Nitrogen-Bearing Steel in PEMFC Environments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, H.; Turner, J. A.

    2008-02-01

    High nitrogen-bearing stainless steels, AISI Type 201 and AL219, were investigated in simulated polymer electrolyte membrane fuel cell (PEMFC) environments to assess the use of these materials in fuel cell bipolar plate applications. Both steels exhibit better corrosion behavior than 316L steel in the same environments. Type 201 steel shows similar but lower interfacial contact resistance (ICR) than 316L, while AL219 steel shows higher ICR than 316L. X-ray photoelectron spectroscopy (XPS) analysis shows that the air-formed films on Type 201 and AL219 are composed of iron oxides, chromium oxide, and manganese oxide. Iron oxides dominate the composition of the air-formedmore » film, specially the outer layer. Chromium oxide dominates passive films. Surface film thicknesses were estimated. The results suggest that high nitrogen-bearing stainless steels are promising materials for PEMFC bipolar plates.« less

  4. 40 CFR 90.318 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... chemiluminescent oxides of nitrogen analyzer as described in this section. (b) Initial and Periodic Interference... and periodic calibration. Prior to its initial use and monthly thereafter, or within one month prior... following table). Example calibration points (%) Acceptable for calibration? 20, 30, 40, 50, 60, 70 No...

  5. 40 CFR 90.318 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... chemiluminescent oxides of nitrogen analyzer as described in this section. (b) Initial and Periodic Interference... and periodic calibration. Prior to its initial use and monthly thereafter, or within one month prior... following table). Example calibration points (%) Acceptable for calibration? 20, 30, 40, 50, 60, 70 No...

  6. 40 CFR 90.318 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... chemiluminescent oxides of nitrogen analyzer as described in this section. (b) Initial and Periodic Interference... and periodic calibration. Prior to its initial use and monthly thereafter, or within one month prior... following table). Example calibration points (%) Acceptable for calibration? 20, 30, 40, 50, 60, 70 No...

  7. Documents for SBAR Panel: Phase I Federal Implementation Plans (FIPs) To Reduce the Regional Transport of Ozone in the Eastern United States

    EPA Pesticide Factsheets

    SBAR panel on regional reductions of nitrogen oxides, with focus on the windborne transport of ozone smog and nitrogen oxides from NOx-producing sources in 22 eastern states and the District of Columbia

  8. Synthesis and characterization of binary titania-silica mixed oxides

    NASA Astrophysics Data System (ADS)

    Budhi, Sridhar

    A series of binary titania-silica mixed oxides were synthesized by the sol-gel method at room temperature. The mixed oxides were prepared that involved the hydrolysis of titanium isopropoxide and tetraethylorthosilicate (TEOS) by co-solvent induced gelation usually in acidic media. The resulting gels were dried, calcined and then characterized by powder X-ray diffractometric studies, nitrogen sorption studies (at 77K), diffuse reflectance spectroscopy, Raman microscopy and transmission electron microscopic studies. The nitrogen sorption studies indicate that the specific surface areas, pore volume, pore diameter and pore size distribution of the mixed oxides were substantially enhanced when non-polar solvents such as toluene, p-xylene or mesitylene were added as co-solvents to the synthesis gel. Transmission electron microscopic (TEM) studies confirm the results obtained from the nitrogen sorption studies. Our results indicate that we can obtain binary metal oxides possessing high surface area and large pore volumes with tunable pore size distribution at room temperature. Photocatalytic evaluation of the mixed oxides is currently in progress.

  9. Mechanical Properties of Degraded PMR-15 Resin

    NASA Technical Reports Server (NTRS)

    Tsuji, Luis C.

    2000-01-01

    Thermo-oxidative aging produces a nonuniform degradation state in PMR-15 resin. A surface layer, usually attributed to oxidative degradation, forms. This surface layer has different properties from the inner material. A set of material tests was designed to separate the properties of the oxidized surface layer from the properties of interior material. Test specimens were aged at 316 C in either air or nitrogen, for durations of up to 800 hr. The thickness of the oxidized surface layer in air aged specimens, and the shrinkage and coefficient of thermal expansion (CTE) of nitrogen aged specimens were measured directly. The nitrogen-aged specimens were assumed to have the same properties as the interior material in the air-aged specimens. Four-point-bend tests were performed to determine modulus of both the oxidized surface layer and the interior material. Bimaterial strip specimens consisting of oxidized surface material and unoxidized interior material were constructed and used to determine surface layer shrinkage and CTE. Results confirm that the surface layer and core materials have substantially different properties.

  10. Explosive decomposition of ethylene oxide at elevated condition: effect of ignition energy, nitrogen dilution, and turbulence.

    PubMed

    Pekalski, A A; Zevenbergen, J F; Braithwaite, M; Lemkowitz, S M; Pasman, H J

    2005-02-14

    Experimental and theoretical investigation of explosive decomposition of ethylene oxide (EO) at fixed initial experimental parameters (T=100 degrees C, P=4 bar) in a 20-l sphere was conducted. Safety-related parameters, namely the maximum explosion pressure, the maximum rate of pressure rise, and the Kd values, were experimentally determined for pure ethylene oxide and ethylene oxide diluted with nitrogen. The influence of the ignition energy on the explosion parameters was also studied. All these dependencies are quantified in empirical formulas. Additionally, the effect of turbulence on explosive decomposition of ethylene oxide was investigated. In contrast to previous studies, it is found that turbulence significantly influences the explosion severity parameters, mostly the rate of pressure rise. Thermodynamic models are used to calculate the maximum explosion pressure of pure and of nitrogen-diluted ethylene oxide, at different initial temperatures. Soot formation was experimentally observed. Relation between the amounts of soot formed and the explosion pressure was experimentally observed and was calculated.

  11. Characteristics of two novel cold- and salt-tolerant ammonia-oxidizing bacteria from Liaohe Estuarine Wetland.

    PubMed

    Huang, Xiao; Bai, Jie; Li, Kui-Ran; Zhao, Yang-Guo; Tian, Wei-Jun; Dang, Jia-Jia

    2017-01-15

    To achieve a better contaminant removal efficiency in a low-temperature and high-salt environment, two novel strains of cold- and salt-tolerant ammonia-oxidizing bacteria (AOB), i.e., Ochrobactrum sp. (HXN-1) and Aquamicrobium sp. (HXN-2), were isolated from the surface sediment of Liaohe Estuarine Wetland (LEW), China. The optimization of initial ammonia nitrogen concentration, pH, carbon-nitrogen ratio, and petroleum hydrocarbons (PHCs) to improve the ammonia-oxidation capacity of the two bacterial strains was studied. Both bacterial strains showed a high ammonia nitrogen removal rate of over 80% under a high salinity of 10‰. Even at a temperature as low as 15°C, HXN-1 and HXN-2 could achieve an ammonia nitrogen removal rate of 53% and 62%, respectively. The cold- and salt-tolerant AOB in this study demonstrated a high potential for ammonia nitrogen removal from LEW. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Soil nitrogen cycling and nitrous oxide flux in a Rocky Mountain Douglas-fir forest - Effects of fertilization, irrigation and carbon addition

    NASA Technical Reports Server (NTRS)

    Matson, Pamela A.; Gower, Stith T.; Volkmann, Carol; Billow, Christine; Grier, Charles C.

    1992-01-01

    Nitrous oxide fluxes and soil nitrogen transformations were measured in experimentally-treated high elevation Douglas-fir forests in northwestern New Mexico, USA. On an annual basis, forests that were fertilized with 200 kg N/ha emitted an average of 0.66 kg/ha of N2O-N, with highest fluxes occurring in July and August when soils were both warm and wet. Control, irrigated, and woodchip treated plots did not differ, and annual average fluxes ranged from 0.03 to 0.23 kg/ha. Annual net nitrogen mineralization and nitrate production were estimated in soil and forest floor using in situ incubations; fertilized soil mineralized 277 kg/ha/y in contrast to 18 kg/ha/y in control plots. Relative recovery of 15NH4-N applied to soil in laboratory incubations was principally in the form of NO3-N in the fertilized soils, while recovery was mostly in microbial biomass-N in the other treatments. Fertilization apparently added nitrogen that exceeded the heterotrophic microbial demand, resulting in higher rates of nitrate production and higher nitrous oxide fluxes. Despite the elevated nitrous oxide emission resulting from fertilization, we estimate that global inputs of nitrogen into forests are not currently contributing significantly to the increasing concentrations of nitrous oxide in the atmosphere.

  13. On the Use of Thermal NF3 as the Fluorination and Oxidation Agent in Treatment of Used Nuclear Fuels

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Scheele, Randall D.; McNamara, Bruce K.; Casella, Andrew M.

    2012-05-01

    This paper presents results of our investigation on the use of nitrogen trifluoride as the fluorination or fluorination/oxidation agent for use in a process for separating valuable constituents from used nuclear fuels by employing the volatility of many transition metal and actinide fluorides. Nitrogen trifluoride is less chemically and reactively hazardous than the hazardous and aggressive fluorinating agents used to prepare uranium hexafluoride and considered for fluoride volatility based nuclear fuels reprocessing. In addition, nitrogen trifluoride’s less aggressive character may be used to separate the volatile fluorides from used fuel and from themselves based on the fluorination reaction’s temperature sensitivitymore » (thermal tunability) rather than relying on differences in sublimation/boiling temperature and sorbents. Our thermodynamic calculations found that nitrogen trifluoride has the potential to produce volatile fission product and actinide fluorides from candidate oxides and metals. Our simultaneous thermogravimetric and differential thermal analyses found that the oxides of lanthanum, cerium, rhodium, and plutonium fluorinated but did not form volatile fluorides and that depending on temperature volatile fluorides formed from the oxides of niobium, molybdenum, ruthenium, tellurium, uranium, and neptunium. We also demonstrated near-quantitative removal of uranium from plutonium in a mixed oxide.« less

  14. Combustion of coal gas fuels in a staged combustor

    NASA Technical Reports Server (NTRS)

    Rosfjord, T. J.; Mcvey, J. B.; Sederquist, R. A.; Schultz, D. F.

    1982-01-01

    Gaseous fuels produced from coal resources generally have heating values much lower than natural gas; the low heating value could result in unstable or inefficient combustion. Coal gas fuels may contain ammonia which if oxidized in an uncontrolled manner could result in unacceptable nitrogen oxide exhaust emission levels. Previous investigations indicate that staged, rich-lean combustion represents a desirable approach to achieve stable, efficient, low nitrogen oxide emission operation for coal-derived liquid fuels contaning up to 0.8-wt pct nitrogen. An experimental program was conducted to determine whether this fuel tolerance can be extended to include coal-derived gaseous fuels. The results of tests with three nitrogen-free fuels having heating values of 100, 250, and 350 Btu/scf and a 250 Btu/scf heating value doped to contain 0.7 pct ammonia are presented.

  15. Microbial nitrogen sinks in the water column of a large coastal hypoxic area, the Gulf of Mexico "Dead Zone"

    NASA Astrophysics Data System (ADS)

    Rogener, M. K.; Roberts, B. J.; Rabalais, N. N.; Stewart, F. J.; Joye, S. B.

    2016-02-01

    Excess nitrogen in coastal environments leads to eutrophication, harmful algal blooms, habitat loss, oxygen depletion and reductions in biodiversity. As such, biological nitrogen (N) removal through the microbially-mediated process of denitrification is a critical ecosystem function that can mitigate the negative consequences of excess nitrogen loading. However, denitrification can produce nitrous oxide, a potent greenhouse gas, as a byproduct under some environmental conditions. To understand how excess nitrogen loading impacts denitrification, we measured rates of this process in the water column of the Gulf of Mexico "Dead Zone" three times over the summer of 2015. The Dead Zone is generated by excessive nitrogen loading from the Mississippi River co-occurring with strong water column stratification, which leads to a large summer-time hypoxic/anoxic area at the mouth of the river and along the coast of Louisiana. Rates of denitrification ranged from 31 to 153 nmol L-1 d-1. Dead Zone waters are also enriched in methane and aerobic methane oxidation rates ranged from 0.1 to 4.3 nmol L-1 d-1. Maximal denitrification rates were observed at stations with the lowest oxygen concentrations and highest methane oxidation rates, suggesting a potential coupling between nitrate reduction and methane oxidation which both scrubs reactive N and methane from the system, thus performing a duel ecosystem service.

  16. Subcritical and supercritical water oxidation of CELSS model wastes

    NASA Technical Reports Server (NTRS)

    Takahashi, Y.; Wydeven, T.; Koo, C.

    1989-01-01

    A mixture of ammonium hydroxide with acetic acid and a slurry of human feces, urine, and wipes were used as CELSS model wastes to be wet-oxidized at temperatures from 250 to 500 C, i.e. below and above the critical point of water (374 C and 218 kg/sq cm or 21.4 MPa). The effects of oxidation temperature ( 250-500 C) and residence time (0-120 mn) on carbon and nitrogen and on metal corrosion from the reactor material were studied. Almost all of the organic matter in the model wastes was oxidized in the temperature range from 400 to 500 C, above the critical conditions for water. In contrast, only a small portion of the organic matter was oxidized at subcritical conditions. A substantial amount of nitrogen remained in solution in the form of ammonia at temperatures ranging from 350 to 450 C suggesting that, around 400 C, organic carbon is completely oxidized and most of the nitrogen is retained in solution. The Hastelloy C-276 alloy reactor corroded during subcritical and supercritical water oxidation.

  17. Ammonia oxidation kinetics determine niche separation of nitrifying Archaea and Bacteria.

    PubMed

    Martens-Habbena, Willm; Berube, Paul M; Urakawa, Hidetoshi; de la Torre, José R; Stahl, David A

    2009-10-15

    The discovery of ammonia oxidation by mesophilic and thermophilic Crenarchaeota and the widespread distribution of these organisms in marine and terrestrial environments indicated an important role for them in the global nitrogen cycle. However, very little is known about their physiology or their contribution to nitrification. Here we report oligotrophic ammonia oxidation kinetics and cellular characteristics of the mesophilic crenarchaeon 'Candidatus Nitrosopumilus maritimus' strain SCM1. Unlike characterized ammonia-oxidizing bacteria, SCM1 is adapted to life under extreme nutrient limitation, sustaining high specific oxidation rates at ammonium concentrations found in open oceans. Its half-saturation constant (K(m) = 133 nM total ammonium) and substrate threshold (

  18. Integrated Science Assessment (ISA) for Oxides of Nitrogen – Health Criteria (Second External Review Draft, 2008)

    EPA Science Inventory

    EPA has announced that the Second External Review Draft of the Integrated Science Assessment (ISA) for Oxides of Nitrogen – Health Criteria has been made available for independent peer review and public review. This draft ISA document represents a concise synthesis and evaluation...

  19. Integrated Science Assessment (ISA) for Oxides of Nitrogen and Sulfur - Ecological Criteria (Final Report, Dec 2008)

    EPA Science Inventory

    EPA announced the availability of the final report, Integrated Science Assessment (ISA) for Oxides of Nitrogen and Sulfur - Ecological Criteria. This document represents a concise synthesis and evaluation of the most policy-relevant science and will ultimately provide the ...

  20. Integrated Science Assessment for Oxides of Nitrogen – Health Criteria (Final Report, Jul 2008)

    EPA Science Inventory

    The Integrated Science Assessment (ISA) for Oxides of Nitrogen – Health Criteria document represents a concise synthesis and evaluation of the most policy-relevant science and will ultimately provide the scientific bases for EPA’s decision regarding whether the current standard f...

  1. 78 FR 27374 - Workshop To Review Initial Draft Materials for the Nitrogen Oxides (NOX

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-10

    ... materials that will inform the development of the NO X Integrated Science Assessment (ISA) for health... ENVIRONMENTAL PROTECTION AGENCY [FRL-9812-6] Workshop To Review Initial Draft Materials for the Nitrogen Oxides (NO X ) Integrated Science Assessment (ISA) for Health Effects AGENCY: Environmental...

  2. DEMONSTRATION PROJECT FOR THE ABATEMENT OF NITROGEN OXIDES EMISSIONS USING REBURN TECHNOLOGY FOR COGENERATION PLANTS IN TAIWAN

    EPA Science Inventory

    The report summarizes the key technical results of a joint demonstration project between the U.S. Environmental Protection Agency and the Taiwan Environmental Protection Administration. The project demonstrated that coal reburning can be used to reduce nitrogen oxides (NOX) emiss...

  3. Nitrogen management to reduce nitrous oxide emissions

    USDA-ARS?s Scientific Manuscript database

    Nitrous oxide (N2O) emissions from agricultural soils represent a complex interaction between the inputs of nitrogen into the soil and the soil environment. Mitigating these emissions will have a positive impact on greenhouse gases. Agriculture is the primary source of N2O emissions and must develop...

  4. Reducing Nitrogen Oxide Emissions: 1996 Compliance with Title IV Limits

    EIA Publications

    1998-01-01

    The purpose of this article is to summarize the existing federal nitrogen oxide (Nox) regulations and the 1996 performance of the 239 Title IV generating units. It also reviews the basics of low-Nox burner technology and presents cost and performance data for retrofits at Title IV units.

  5. 40 CFR 60.44b - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for nitrogen oxides (NOX). 60.44b Section 60.44b Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... technological system of emission reduction applied when demonstrating compliance under paragraph (f)(1)(i) of...

  6. 40 CFR 60.44b - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for nitrogen oxides (NOX). 60.44b Section 60.44b Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... technological system of emission reduction applied when demonstrating compliance under paragraph (f)(1)(i) of...

  7. 40 CFR 60.44b - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for nitrogen oxides (NOX). 60.44b Section 60.44b Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... technological system of emission reduction applied when demonstrating compliance under paragraph (f)(1)(i) of...

  8. 40 CFR 60.44b - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for nitrogen oxides (NOX). 60.44b Section 60.44b Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... technological system of emission reduction applied when demonstrating compliance under paragraph (f)(1)(i) of...

  9. 40 CFR 60.44b - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for nitrogen oxides (NOX). 60.44b Section 60.44b Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... technological system of emission reduction applied when demonstrating compliance under paragraph (f)(1)(i) of...

  10. Dynamic model evaluation for secondary inorganic aerosol and its precursors over Europe between 1990 and 2009

    NASA Astrophysics Data System (ADS)

    Banzhaf, S.; Schaap, M.; Kranenburg, R.; Manders, A. M. M.; Segers, A. J.; Visschedijk, A. J. H.; Denier van der Gon, H. A. C.; Kuenen, J. J. P.; van Meijgaard, E.; van Ulft, L. H.; Cofala, J.; Builtjes, P. J. H.

    2015-04-01

    In this study we present a dynamic model evaluation of chemistry transport model LOTOS-EUROS (LOng Term Ozone Simulation - EURopean Operational Smog) to analyse the ability of the model to reproduce observed non-linear responses to emission changes and interannual variability of secondary inorganic aerosol (SIA) and its precursors over Europe from 1990 to 2009. The 20 year simulation was performed using a consistent set of meteorological data provided by RACMO2 (Regional Atmospheric Climate MOdel). Observations at European rural background sites have been used as a reference for the model evaluation. To ensure the consistency of the used observational data, stringent selection criteria were applied, including a comprehensive visual screening to remove suspicious data from the analysis. The LOTOS-EUROS model was able to capture a large part of the seasonal and interannual variability of SIA and its precursors' concentrations. The dynamic evaluation has shown that the model is able to simulate the declining trends observed for all considered sulfur and nitrogen components following the implementation of emission abatement strategies for SIA precursors over Europe. Both the observations and the model show the largest part of the decline in the 1990s, while smaller concentration changes and an increasing number of non-significant trends are observed and modelled between 2000 and 2009. Furthermore, the results confirm former studies showing that the observed trends in sulfate and total nitrate concentrations from 1990 to 2009 are lower than the trends in precursor emissions and precursor concentrations. The model captured well these non-linear responses to the emission changes. Using the LOTOS-EUROS source apportionment module, trends in the formation efficiency of SIA have been quantified for four European regions. The exercise has revealed a 20-50% more efficient sulfate formation in 2009 compared to 1990 and an up to 20% more efficient nitrate formation per unit nitrogen oxide emission, which added to the explanation of the non-linear responses. However, we have also identified some weaknesses in the model and the input data. LOTOS-EUROS underestimates the observed nitrogen dioxide concentrations throughout the whole time period, while it overestimates the observed nitrogen dioxide concentration trends. Moreover, model results suggest that the emission information of the early 1990s used in this study needs to be improved concerning magnitude and spatial distribution.

  11. Dynamic model evaluation for secondary inorganic aerosol and its precursors over Europe between 1990 and 2009

    NASA Astrophysics Data System (ADS)

    Banzhaf, S.; Schaap, M.; Kranenburg, R.; Manders, A. M. M.; Segers, A. J.; Visschedijk, A. H. J.; Denier van der Gon, H. A. C.; Kuenen, J. J. P.; van Meijgaard, E.; van Ulft, L. H.; Cofala, J.; Builtjes, P. J. H.

    2014-07-01

    In this study we present a dynamic model evaluation of the chemistry transport model LOTOS-EUROS to analyse the ability of the model to reproduce observed non-linear responses to emission changes and interannual variability of secondary inorganic aerosol (SIA) and its precursors over Europe from 1990 to 2009. The 20 year simulation was performed using a consistent set of meteorological data provided by the regional climate model RACMO2. Observations at European rural background sites have been used as reference for the model evaluation. To ensure the consistency of the used observational data stringent selection criteria were applied including a comprehensive visual screening to remove suspicious data from the analysis. The LOTOS-EUROS model was able to capture a large part of the day-to-day, seasonal and interannual variability of SIA and its precursors' concentrations. The dynamic evaluation has shown that the model is able to simulate the declining trends observed for all considered sulphur and nitrogen components following the implementation of emission abatement strategies for SIA precursors over Europe. Both, the observations and the model show the largest part of the decline in the 1990's while smaller concentration changes and an increasing number of non-significant trends are observed and modelled between 2000-2009. Furthermore, the results confirm former studies showing that the observed trends in sulphate and total nitrate concentrations from 1990 to 2009 are significantly lower than the trends in precursor emissions and precursor concentrations. The model captured these non-linear responses to the emission changes well. Using the LOTOS-EUROS source apportionment module trends in formation efficiency of SIA have been quantified for four European regions. The exercise has revealed a 20-50% more efficient sulphate formation in 2009 compared to 1990 and an up to 20% more efficient nitrate formation per unit nitrogen oxide emission, which added to the explanation of the non-linear responses. However, we have also identified some weaknesses to the model and the input data. LOTOS-EUROS underestimates the observed nitrogen dioxide concentrations throughout the whole time period, while it overestimates the observed nitrogen dioxide concentration trends. Moreover, model results suggest that the emission information of the early 1990's used in this study needs to be improved concerning magnitude and spatial distribution.

  12. Enhancing nitrogen removal in an Orbal oxidation ditch by optimization of oxygen supply: practice in a full-scale municipal wastewater treatment plant.

    PubMed

    Zhou, Xin; Guo, Xuesong; Han, Yunping; Liu, Junxin; Ren, Jincheng; Wang, Yu; Guo, Yantao

    2012-09-01

    Seven different aeration modes, in which oxygen supply was changed by adjusting the number of aerators, were designed and applied in a full-scale municipal wastewater treatment plant with Orbal oxidation ditch to investigate the influence of dissolved oxygen (DO) on nitrogen removal performance. The full-scale experiment results of 574 days showed that nitrogen removal efficiency depended on the degree of nitrification and denitrification in the outer channel, which was the largest contributor for TN removal in the Orbal oxidation ditch. Appropriate aeration control in the outer channel was essential to balance nitrification and denitrification in the Orbal oxidation ditch. When DO was as low as about 0.2 mg/L in the outer channel, the highest TN removal efficiency of 75% was obtained. Microbial analysis confirmed that aerobic and anaerobic bacteria coexisted in the outer channel. The greater species diversity and more intensive activities of these bacteria in aeration Mode V may be responsible for the higher TN removal efficiency compared with Mode III. These results suggest that different aerated conditions in the Orbal oxidation ditch might have a significant effect on microbial community characteristics and nitrogen removal efficiencies.

  13. Integrated Science Assessment (ISA) for Oxides of Nitrogen ...

    EPA Pesticide Factsheets

    This draft ISA document represents a concise synthesis and evaluation of the most policy-relevant science and will ultimately provide the scientific bases for EPA’s decision on retaining or revising the current secondary standards for NO2, SO2, PM 2.5 and PM 10 since the prior release of the assessment. The intent of the ISA, according to the CAA, is to “accurately reflect the latest scientific knowledge expected from the presence of [a] pollutant in ambient air” (U.S. Code, 1970a, 1970b). It includes scientific research from atmospheric sciences, exposure and deposition, biogeochemistry, hydrology, soil science, marine science, plant physiology, animal physiology, and ecology conducted at multiple scales (e.g., population, community, ecosystem, landscape levels). Key information and judgments formerly found in the Air Quality Criteria Documents (AQCDs) for oxides of nitrogen, oxides of nitrogen and particulate matter for ecological effects are included; Appendixes provide additional details supporting the ISA. Together, the ISA and Appendixes serve to update and revise the last oxides of nitrogen and oxides of sulfur ISA which was published in 2008 and the ecological portion of the last particulate matter ISA, which was published in 2009.

  14. Regenerative process and system for the simultaneous removal of particulates and the oxides of sulfur and nitrogen from a gas stream

    DOEpatents

    Cohen, M.R.; Gal, E.

    1993-04-13

    A process and system are described for simultaneously removing from a gaseous mixture, sulfur oxides by means of a solid sulfur oxide acceptor on a porous carrier, nitrogen oxides by means of ammonia gas and particulate matter by means of filtration and for the regeneration of loaded solid sulfur oxide acceptor. Finely-divided solid sulfur oxide acceptor is entrained in a gaseous mixture to deplete sulfur oxides from the gaseous mixture, the finely-divided solid sulfur oxide acceptor being dispersed on a porous carrier material having a particle size up to about 200 microns. In the process, the gaseous mixture is optionally pre-filtered to remove particulate matter and thereafter finely-divided solid sulfur oxide acceptor is injected into the gaseous mixture.

  15. Nitrogen removal from sludge digester liquids by nitrification/denitrification or partial nitritation/anammox: environmental and economical considerations.

    PubMed

    Fux, C; Siegrist, H

    2004-01-01

    In wastewater treatment plants with anaerobic sludge digestion, 15-20% of the nitrogen load is recirculated to the main stream with the return liquors from dewatering. Separate treatment of this ammonium-rich digester supernatant significantly reduces the nitrogen load of the activated sludge system. Two biological applications are considered for nitrogen elimination: (i) classical autotrophic nitrification/heterotrophic denitrification and (ii) partial nitritation/autotrophic anaerobic ammonium oxidation (anammox). With both applications 85-90% nitrogen removal can be achieved, but there are considerable differences in terms of sustainability and costs. The final gaseous products for heterotrophic denitrification are generally not measured and are assumed to be nitrogen gas (N2). However, significant nitrous oxide (N2O) production can occur at elevated nitrite concentrations in the reactor. Denitrification via nitrite instead of nitrate has been promoted in recent years in order to reduce the oxygen and the organic carbon requirements. Obviously this "achievement" turns out to be rather disadvantageous from an overall environmental point of view. On the other hand no unfavorable intermediates are emitted during anaerobic ammonium oxidation. A cost estimate for both applications demonstrates that partial nitritation/anammox is also more economical than classical nitrification/denitrification. Therefore autotrophic nitrogen elimination should be used in future to treat ammonium-rich sludge liquors.

  16. Reactive Nitrogen Partitioning and its Relationship to Winter Ozone Events in Utah

    NASA Astrophysics Data System (ADS)

    Wild, R. J.; Cohen, R. C.; Dube, W. P.; Edwards, P. M.; Holloway, J.; Kercher, J. P.; Lee, L.; McLaren, R.; Roberts, J. M.; Stutz, J.; Veres, P. R.; Warneke, C.; Williams, E. J.; Yuan, B.; Brown, S. S.

    2013-12-01

    Recent air quality measurements have shown anomalously large concentrations of wintertime ozone in Utah's Uintah Basin, host to intensive oil and gas operations. As part of the Uintah Basin Winter Ozone Studies (UBWOS) in January-February of 2012 and 2013, a variety of instruments were deployed to measure speciated reactive nitrogen and ozone. Here we present an analysis and comparison of reactive nitrogen data for the two years. We also describe a recently developed measurement of total reactive nitrogen (NOy) by cavity ring-down spectroscopy, which was deployed for the first time in 2013. Compared to 2012, which had very different meteorological conditions, ozone production rates in 2013 were roughly three times faster, leading to numerous and substantial exceedances of national air quality standards. Furthermore, despite considerably higher NOy levels in 2013 compared to 2012, levels of photochemically active NOx was remarkably similar between the two years. Much of the reactive nitrogen oxidation occurred at night, suggesting that nighttime processes played an important role in defining the conditions for daytime photochemistry. Our findings regarding the reactive nitrogen budget help us understand the role different NOx oxidation processes in O3 photochemistry, as well as the overall sensitivity of O3 production to nitrogen oxides in this environment.

  17. Detailed mechanism of benzene oxidation

    NASA Technical Reports Server (NTRS)

    Bittker, David A.

    1987-01-01

    A detailed quantitative mechanism for the oxidation of benzene in both argon and nitrogen diluted systems is presented. Computed ignition delay time for argon diluted mixtures are in satisfactory agreement with experimental results for a wide range of initial conditions. An experimental temperature versus time profile for a nitrogen diluted oxidation was accurately matched and several concentration profiles were matched qualitatively. Application of sensitivity analysis has given approximate rate constant expressions for the two dominant heat release reactions, the oxidation of C6H5 and C5H5 radicals by molecular oxygen.

  18. Erratum to ;Coastal water column ammonium and nitrite oxidation are decoupled in summer;

    NASA Astrophysics Data System (ADS)

    Heiss, Elise M.; Fulweiler, Robinson W.

    2017-07-01

    Water column nitrification is a key process in the nitrogen cycle as it links reduced and oxidized forms of nitrogen and also provides the substrate (nitrate) needed for reactive nitrogen removal by denitrification. We measured potential water column ammonium and nitrite oxidation rates at four sites along an estuary to continental shelf gradient over two summers. In most cases, nitrite oxidation rates outpaced ammonium oxidation rates. Overall, ammonium and nitrite oxidation rates were higher outside of the estuary, and this trend was primarily driven by higher oxidation rates in deeper waters. Additionally, both ammonium and nitrite oxidation rates were impacted by different in situ variables. Ammonium oxidation rates throughout the water column as a whole were most positively correlated to depth and salinity and negatively correlated to dissolved oxygen, light, and temperature. In contrast, nitrite oxidation rates throughout the water column were negatively correlated with temperature, light and pH. Multivariate regression analysis revealed that surface (<20 m) ammonium oxidation rates were most strongly predicted by substrate (NH4+), salinity, and light, while deep (>20 m) rates were regulated by temperature, light, and [H+] (i.e. pH). In addition, surface (<20 m) nitrite oxidation rates were best explained by [H+] alone, while [H+], temperature, and dissolved oxygen all played a role in predicting deep (>20 m) nitrite oxidation rates. These results support the growing body of evidence that ammonium oxidation and nitrite oxidation are not always coupled, should be measured separately, and are influenced by different environmental conditions.

  19. Measurement of gaseous emissions from an afterburning turbojet engine at simulated altitude conditions

    NASA Technical Reports Server (NTRS)

    Diehl, L. A.

    1973-01-01

    Gaseous emissions from a J85-GE-13 turbojet engine were measured over a range of fuel-air ratios from idle to full afterburning and simulated altitudes from near sea-level to 12,800 meters (42,000 ft). Without afterburning, carbon monoxide and unburned hydrocarbon emissions were highest at idle and lowest at takeoff; oxides of nitrogen exhibited the reverse trend. With afterburning, carbon monoxide and unburned hydrocarbon emissions were greater than for military power. Carbon monoxide emissions were altitude dependent. Oxides of nitrogen emissions were less at minimum afterburning than at military power. For power levels above minimum afterburning, the oxides of nitrogen emissions were both power level and altitude dependent.

  20. Well-dispersed NiO nanoparticles supported on nitrogen-doped carbon nanotube for methanol electrocatalytic oxidation in alkaline media

    NASA Astrophysics Data System (ADS)

    Wang, Pengcheng; Zhou, Yingke; Hu, Min; Chen, Jian

    2017-01-01

    Nitrogen-doped carbon nanotube supporting NiO nanoparticles were synthesized by a chemical precipitation process coupled with subsequent calcination. The morphology and structure of the composites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and the electrochemical performance was evaluated using cyclic voltammetry and chronoamperometric technique. The effects of nitrogen doping, calcination temperature and content of NiO nanoparticles on the electrocatalytic activity toward methanol oxidation were systematically studied. The results show that the uniformly dispersed ultrafine NiO nanoparticles supported on nitrogen-doped carbon nanotube are obtained after calcination at 400 °C. The optimized composite catalysts present high electrocatalytic activity, fast charge-transfer process, excellent accessibility and stability for methanol oxidation reaction, which are promising for application in the alkaline direct methanol fuel cells.

  1. Spatial Scale Variability of NH3 and Impacts to interpolated Concentration Grids

    EPA Science Inventory

    Over the past decade, reduced nitrogen (NH3, NH4) has become an important component of atmospheric nitrogen deposition due to increases in agricultural activities and reductions in oxidized sulfur and nitrogen emissions from the power sector and mobile sources. Reduced nitrogen i...

  2. [Screening and ammoxidation characteristics of an ammonium oxidizing bacteria group].

    PubMed

    Yang, Xiaolong; Liu, Lihua; Wu, Bingqi; Liu, Shujie; Chen, Fuming

    2015-12-04

    This study aimed to screen high-performance ammonia oxidizing bacteria ( AOB) resistant to a high concentration of ammonia-nitrogen and low C/N ratio, for the development of novel AOB agents. Multi-point sampling, compulsory domestication, gradient dilution of domestication liquid were conducted to screen AOB with efficient and stable ammonia-nitrogen removing ability, and effects of different factors on its ammoxidation ability including C/N ratio, shaking speed and ammonia-nitrogen concentration were studied. Dominant strains were screened and identified by morphological observation, physiological and biochemical properties test and 16S rRNA sequence analysis. Three efficient AOB were obtained, among them a micro-flora named JQ8 showed the highest activity. The ammonia-nitrogen removal rate reached 95. 07% in a simulated wastewater with 17. 86 mmol/L of initial ammonia-nitrogen at C/N 4 treated by JQ8 for 6 days. Moreover, its ammonia nitrogen removal rate kept above 95% and net nitrogen removing rate nearly 80% in the solution with a C/N ratio above 4 and an NH₄⁺-N concentration below 28.57 mmol/L. The circuit board industry wastewater was treated using the laboratory-simulated aerobic active sludge disposal system. The removal rate of NH₄⁺-N and total nitrogen reached 87.8% and 67.6% respectively after 7 days' treatment using JQ8. Defluvibacter sp., Paracoccus sp. and Aquamicrobium sp. were identified as the dominant strains after the composition analysis of JQ8. An ammonia oxidizing bacteria consortium JQ8 screened from the landfill leachate showed a strong ammonium-nitrogen removal and endurance ability under low C/N ratio and high ammonia-nitrogen concentration, thus is probably applicable to intensify the ammonia-nitrogen removal treatment of industrial wastewater with sewage disposal system.

  3. Synthesis of honeycomb-like mesoporous nitrogen-doped carbon nanospheres as Pt catalyst supports for methanol oxidation in alkaline media

    NASA Astrophysics Data System (ADS)

    Zhang, Yunmao; Liu, Yong; Liu, Weihua; Li, Xiying; Mao, Liqun

    2017-06-01

    This paper reports the convenient synthesis of honeycomb-like mesoporous nitrogen-doped carbon spheres (MNCS) using a self-assembly strategy that employs dopamine (DA) as a carbon and nitrogen precursor and a polystyrene-b-poly(ethylene oxide) (PS173-b-PEO170) diblock copolymer as a soft template. The MNCS have large BET surface areas of up to 554 m2 g-1 and high nitrogen contents of up to 6.9 wt%. The obtained MNCS are used as a support for Pt catalysts, which promote methanol oxidation in alkaline media. The MNCS-supported Pt (Pt/MNCS) catalyst has a larger electrochemically active surface area (ESA) (89.2 m2 g-1) than does a commercially available Vulcan XC-72R supported Pt/C catalyst. Compared to the Pt/C catalyst, Pt/MNCS displays a higher peak current density (1007 mA mg-1) and is more stable during methanol oxidation. These improvements are attributed to the honeycomb-like porous structure of the MNCS and the introduction of nitrogen to the carbon support. The MNCS effectively stabilize Pt nanoparticles and assuage the agglomeration of the nanoparticles, suggesting that MNCS are potential and promising application as electrocatalyst supports in alkaline direct methanol fuel cells.

  4. Corn nitrogen management influences nitrous oxide emissions in drained and undrained soils

    USDA-ARS?s Scientific Manuscript database

    Tile-drainage and nitrogen (N) fertilization are important for corn (Zea mays L.) production. To date, no studies have evaluated nitrous oxide (N2O) emissions of single vs. split-N fertilizer application under different soil drainage conditions. The objective of this study was to quantify season-lon...

  5. Quantification of Lightning-induced Nitrogen Oxides in CMAQ and the Assessment of its impact on Ground-level Air Quality

    EPA Science Inventory

    Lightning-induced nitrogen oxides (LNOX), in the presence of sunlight, volatile organic compounds and water, can be a relatively large but uncertain source for ozone (O3) and hydroxyl radical (OH) in the atmosphere. Using lightning flash data from the National Lightning Detection...

  6. Integrated Science Assessment (ISA) for Oxides of Nitrogen – Health Criteria (Second External Review Draft, 2015)

    EPA Science Inventory

    This draft document provides EPA’s evaluation and synthesis of the most policy-relevant science related to the health effects of oxides of nitrogen. When final, it will provide a critical part of the scientific foundation for EPA’s decision regarding the adequacy of the current ...

  7. 40 CFR 77.6 - Penalties for excess emissions of sulfur dioxide and nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Penalties for excess emissions of sulfur dioxide and nitrogen oxides. 77.6 Section 77.6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) EXCESS EMISSIONS § 77.6 Penalties for excess emissions of...

  8. Integrated Science Assessment (ISA) for Oxides of Nitrogen – Health Criteria (First External Review Draft, 2007)

    EPA Science Inventory

    EPA has announced that the First External Review Draft of the Integrated Science Assessment (ISA) for Oxides of Nitrogen – Health Criteria has been made available for independent peer review and public review. This draft ISA document represents a concise synthesis and eva...

  9. Integrated Science Assessment (ISA) for Oxides of Nitrogen and Sulfur - Environmental Criteria (Second External Review Draft, Aug 2008)

    EPA Science Inventory

    EPA has announced that the Second External Review Draft of the Integrated Science Assessment (ISA) for Oxides of Nitrogen and Sulfur - Environmental Criteria has been made available for independent peer review and public review. This draft ISA document represents a conci...

  10. Integrated Science Assessment (ISA) for Oxides of Nitrogen and Sulfur - Environmental Criteria (First External Review Draft, Dec 2007)

    EPA Science Inventory

    EPA is announcing that the First External Review Draft of the Integrated Science Assessment (ISA) for Oxides of Nitrogen and Sulfur – Environmental Criteria has been made available for independent peer review and public review. This draft ISA document represents a concise ...

  11. 40 CFR 86.332-79 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Emission Regulations for New Gasoline-Fueled and Diesel-Fueled Heavy-Duty Engines; Gaseous Exhaust Test.... (2) Zero the oxides of nitrogen analyzer. (3) Connect the outlet of the NOX generator (see Figure D79... operating range. (4) Introduce into the NOX generator-analyzer system a span gas with a NO concentration...

  12. 40 CFR 86.332-79 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Emission Regulations for New Gasoline-Fueled and Diesel-Fueled Heavy-Duty Engines; Gaseous Exhaust Test.... (2) Zero the oxides of nitrogen analyzer. (3) Connect the outlet of the NOX generator (see Figure D79... operating range. (4) Introduce into the NOX generator-analyzer system a span gas with a NO concentration...

  13. 40 CFR 90.318 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... chemiluminescent oxides of nitrogen analyzer as described in this section. (b) Initial and Periodic Interference...-squares best-fit straight line is two percent or less of the value at each data point, calculate... at any point, use the best-fit non-linear equation which represents the data to within two percent of...

  14. 40 CFR 90.318 - Oxides of nitrogen analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... chemiluminescent oxides of nitrogen analyzer as described in this section. (b) Initial and Periodic Interference...-squares best-fit straight line is two percent or less of the value at each data point, calculate... at any point, use the best-fit non-linear equation which represents the data to within two percent of...

  15. Integrated Science Assessment (ISA) for Oxides of Nitrogen – Health Criteria (First External Review Draft, 2013)

    EPA Science Inventory

    EPA is announcing the availability of the First External Review Draft of the Integrated Science Assessment for Oxides of Nitrogen – Health Criteria for public comment and independent peer review. This draft document provides EPA’s evaluation and synthesis of the most polic...

  16. COMBUSTION MODIFICATION CONTROL OF NITROGEN OXIDES (EPA/600/F-95/012)

    EPA Science Inventory

    EPA's efforts in research and development of nitrogen oxide (NOx) control technologies by
    means of modifying the combustion process have played a major role in reducing stationary
    source NOx emissions by over 3 million tons (2.73 x 10^6 tonnes) annually, and have led to at<...

  17. 75 FR 64155 - Approval of Implementation Plans of Wisconsin: Nitrogen Oxides Reasonably Available Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-19

    ..., 2009. These revisions incorporate provisions related to the implementation of nitrogen oxides (NO X... ozone nonattainment areas. EPA is approving SIP revisions that address the NO X RACT requirements found in the Clean Air Act (CAA). EPA is also approving other miscellaneous rule changes that affect NO X...

  18. 75 FR 64951 - Approval and Promulgation of Implementation Plans; Illinois; Voluntary Nitrogen Oxides Controls

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-21

    ... for regulations governing Nitrogen Oxides (NO X ) emission allowances granted for implementation of voluntary control of NO X emissions from sources other than those covered by other Illinois NO X emission..., which would have incorporated a rule governing NO X emission allowances (estimation and crediting of NO...

  19. Mapping the diatom redox-sensitive proteome provides insight into response to nitrogen stress in the marine environment.

    PubMed

    Rosenwasser, Shilo; Graff van Creveld, Shiri; Schatz, Daniella; Malitsky, Sergey; Tzfadia, Oren; Aharoni, Asaph; Levin, Yishai; Gabashvili, Alexandra; Feldmesser, Ester; Vardi, Assaf

    2014-02-18

    Diatoms are ubiquitous marine photosynthetic eukaryotes responsible for approximately 20% of global photosynthesis. Little is known about the redox-based mechanisms that mediate diatom sensing and acclimation to environmental stress. Here we used a quantitative mass spectrometry-based approach to elucidate the redox-sensitive signaling network (redoxome) mediating the response of diatoms to oxidative stress. We quantified the degree of oxidation of 3,845 cysteines in the Phaeodactylum tricornutum proteome and identified approximately 300 redox-sensitive proteins. Intriguingly, we found redox-sensitive thiols in numerous enzymes composing the nitrogen assimilation pathway and the recently discovered diatom urea cycle. In agreement with this finding, the flux from nitrate into glutamine and glutamate, measured by the incorporation of (15)N, was strongly inhibited under oxidative stress conditions. Furthermore, by targeting the redox-sensitive GFP sensor to various subcellular localizations, we mapped organelle-specific oxidation patterns in response to variations in nitrogen quota and quality. We propose that redox regulation of nitrogen metabolism allows rapid metabolic plasticity to ensure cellular homeostasis, and thus is essential for the ecological success of diatoms in the marine ecosystem.

  20. Suppressing Nitrite-oxidizing Bacteria Growth to Achieve Nitrogen Removal from Domestic Wastewater via Anammox Using Intermittent Aeration with Low Dissolved Oxygen

    PubMed Central

    Ma, Bin; Bao, Peng; Wei, Yan; Zhu, Guibing; Yuan, Zhiguo; Peng, Yongzhen

    2015-01-01

    Achieving nitrogen removal from domestic wastewater using anaerobic ammonium oxidation (anammox) has the potential to make wastewater treatment energy-neutral or even energy-positive. The challenge is to suppress the growth of nitrite-oxidizing bacteria (NOB). This study presents a promising method based on intermittent aeration with low dissolved oxygen to limit NOB growth, thereby providing an advantage to anammox bacteria to form a partnership with the ammonium-oxidizing bacteria (AOB). The results showed that NOB was successfully suppressed using that method, with the relative abundance of NOB maintained between 2.0–2.6%, based on Fluorescent in-situ Hybridization. Nitrogen could be effectively removed from domestic wastewater with anammox at a temperature above 20 °C, with an effluent total nitrogen (TN) concentration of 6.6 ± 2.7 mg/L, while the influent TN and soluble chemical oxygen demand were 62.6 ± 3.1 mg/L and 88.0 ± 8.1 mg/L, respectively. PMID:26354321

  1. Reduction of Nitrogen Oxides Emissions from a Coal-Fired Boiler Unit

    NASA Astrophysics Data System (ADS)

    Zhuikov, Andrey V.; Feoktistov, Dmitry V.; Koshurnikova, Natalya N.; Zlenko, Lyudmila V.

    2016-02-01

    During combustion of fossil fuels a large amount of harmful substances are discharged into the atmospheres of cities by industrial heating boiler houses. The most harmful substances among them are nitrogen oxides. The paper presents one of the most effective technological solutions for suppressing nitrogen oxides; it is arrangement of circulation process with additional mounting of the nozzle directed into the bottom of the ash hopper. When brown high-moisture coals are burnt in the medium power boilers, generally fuel nitrogen oxides are produced. It is possible to reduce their production by two ways: lowering the temperature in the core of the torch or decreasing the excess-air factor in the boiler furnace. Proposed solution includes the arrangement of burning process with additional nozzle installed in the lower part of the ash hopper. Air supply from these nozzles creates vortex involving large unburned fuel particles in multiple circulations. Thereby time of their staying in the combustion zone is prolonging. The findings describe the results of the proposed solution; and recommendations for the use of this technological method are given for other boilers.

  2. General Synthesis of Transition-Metal Oxide Hollow Nanospheres/Nitrogen-Doped Graphene Hybrids by Metal-Ammine Complex Chemistry for High-Performance Lithium-Ion Batteries.

    PubMed

    Chen, Jiayuan; Wu, Xiaofeng; Gong, Yan; Wang, Pengfei; Li, Wenhui; Mo, Shengpeng; Peng, Shengpan; Tan, Qiangqiang; Chen, Yunfa

    2018-02-09

    We present a general and facile synthesis strategy, on the basis of metal-ammine complex chemistry, for synthesizing hollow transition-metal oxides (Co 3 O 4 , NiO, CuO-Cu 2 O, and ZnO)/nitrogen-doped graphene hybrids, potentially applied in high-performance lithium-ion batteries. The oxygen-containing functional groups of graphene oxide play a prerequisite role in the formation of hollow transition-metal oxides on graphene nanosheets, and a significant hollowing process occurs only when forming metal (Co 2+ , Ni 2+ , Cu 2+ , or Zn 2+ )-ammine complex ions. Moreover, the hollowing process is well correlated with the complexing capacity between metal ions and NH 3 molecules. The significant hollowing process occurs for strong metal-ammine complex ions including Co 2+ , Ni 2+ , Cu 2+ , and Zn 2+ ions, and no hollow structures formed for weak and/or noncomplex Mn 2+ and Fe 3+ ions. Simultaneously, this novel strategy can also achieve the direct doping of nitrogen atoms into the graphene framework. The electrochemical performance of two typical hollow Co 3 O 4 or NiO/nitrogen-doped graphene hybrids was evaluated by their use as anodic materials. It was demonstrated that these unique nanostructured hybrids, in contrast with the bare counterparts, solid transition-metal oxides/nitrogen-doped graphene hybrids, perform with significantly improved specific capacity, superior rate capability, and excellent capacity retention. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. A Method to Exchange Air Nitrogen Emission Reductions for Watershed Nitrogen Load Reductions

    EPA Science Inventory

    Presentation of the method developed for the Chesapeake Bay Program to estimate changes in nitrogen loading to Chesapeake due to changes in Bay State state-level nitrogen oxide emissions to support air-water trading by the Bay States. Type for SticsUnder AMAD Application QAPP, QA...

  4. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Brosha, Eric L; Mukundan, Rangachary; Nelson, Mark A

    The purpose of this research effort is to develop a low cost on-board Nitrogen Oxide (NO{sub x})/Ammonia (NH{sub 3}) sensor that can not only be used for emissions control but has the potential to improve efficiency through better monitoring of the combustion process and feedback control in both vehicle and stationary systems. Over the past decade, Los AJamos National Laboratory (LANL) has developed a unique class of electrochemical gas sensors for the detection of carbon monoxide, hydrocarbons, hydrogen and nitrogen oxides. These sensors are based on the mixed-potential phenomenon and are a modification of the existing automotive lambda (oxygen) sensormore » and have the potential to meet the stringent sensitivity, selectivity and stability requirements of an on-board emissions/engine control sensor system. The current state of the art LANL technology is based on the stabilization of the electrochemical interfaces and relies on an externally heated, hand-made, tape cast device. We are now poised to apply our patented sensing principles in a mass production sensor platform that is more suitable for real world engine-out testing such as on dynamometers for vehicle applications and for exhaust-out testing in heavy boilers/SCR systems in power plants. In this present work, our goal is to advance towards commercialization of this technology by packaging the unique LANL sensor design in a standard automotive sensor-type platform. This work is being performed with the help of a leading US technical ceramics firm, utilizing commercial manufacturing techniques. Initial tape cast platforms with screen printed metal oxide and Pt sensor electrodes have shown promising results but also clearly show the need for us to optimize the electrode and electrolyte compositions/morphologies and interfaces of these devices in order to demonstrate a sensitive, selective, and stable NO{sub x} sensor. Our previous methods and routes to preparing stable and reproducible mixed potential sensors - in bulk, tape cast, and thin film variants - need to be adapted as a necessary adjunct to address materials challenges resulting from the implementation of commercial manufacturing methods. We also modified the electrodes to demonstrate a NH{sub 3} sensor that can be used in conjunction with the NO{sub x} sensor for feedback control of emissions systems. Once desirable properties are achieved, we will work closely with potential customers in order to dynamometer and boiler test these devices. Ultimately, this will accurately gauge the level of readiness of mixed potential sensor technology for commercialization and eventual use of this important electrochemical technology.« less

  5. The Ecological and Economic Assessment of Efficiency of Environmental Technologies for CHPP (Combined Heat And Power Plant)

    NASA Astrophysics Data System (ADS)

    Rostuntsova, I. A.; Novichkov, S. V.; Zakharov, O. V.; Kochetkov, A. V.

    2017-11-01

    The analysis of the trial-industrial research of the effectiveness of burning water fuel mixtures in steam boilers of medium and high pressure at the combustion of natural gas and fuel oil is carried out. As a result of a research decrease in nitrogen oxide concentration is depending on the amount of moisture pumped to the boilers and type of the incinerated fuel. The theoretical model of the formation of nitrogen oxides in the furnace of the boiler in order to optimize the combustion process with the introduction of moisture, whereby to determine the concentrations of nitrogen oxides formed in the combustion process of the method of expansion of the exponential is received. The dependences of the maximal temperature of a torch, reaction rate of formation of nitrogen oxides, the conditional time of reaction, theoretical concentration of nitrogen oxides taking into account input of moisture in a fire chamber of a copper and coefficient of an exit of nitrogen oxides are defined at combustion of fuel taking into account moisture input. The divergence between the experimental and the theoretical value of the NOx concentration does not exceed 3.8%. The methodical provisions of the economic assessment of concentrations of pollutants reduction when entering the water are drafted. The rate the net present value (NPV) is applied. The optimal water-fuel ratio is selected based on the maximum value of the net present value (NPV). The evaluation of the application of environmental protection measures carried out taking into account the fact that by reducing the emission values in the implementation of this activity will decrease the amount of payment for emissions of polluting substances, which are collected from the profits of the enterprise. The cost estimate for the implementation of environmental activities carried out on the basis of lump-sum costs and current costs in environmental technology (increased fuel and water consumption).

  6. Ultrafine particles and nitrogen oxides generated by gas and electric cooking

    PubMed Central

    Dennekamp, M; Howarth, S; Dick, C; Cherrie, J; Donaldson, K; Seaton, A

    2001-01-01

    OBJECTIVES—To measure the concentrations of particles less than 100 nm diameter and of oxides of nitrogen generated by cooking with gas and electricity, to comment on possible hazards to health in poorly ventilated kitchens.
METHODS—Experiments with gas and electric rings, grills, and ovens were used to compare different cooking procedures. Nitrogen oxides (NOx) were measured by a chemiluminescent ML9841A NOx analyser. A TSI 3934 scanning mobility particle sizer was used to measure average number concentration and size distribution of aerosols in the size range 10-500 nm.
RESULTS—High concentrations of particles are generated by gas combustion, by frying, and by cooking of fatty foods. Electric rings and grills may also generate particles from their surfaces. In experiments where gas burning was the most important source of particles, most particles were in the size range 15-40 nm. When bacon was fried on the gas or electric rings the particles were of larger diameter, in the size range 50-100 nm. The smaller particles generated during experiments grew in size with time because of coagulation. Substantial concentrations of NOX were generated during cooking on gas; four rings for 15 minutes produced 5 minute peaks of about 1000 ppb nitrogen dioxide and about 2000 ppb nitric oxide.
CONCLUSIONS—Cooking in a poorly ventilated kitchen may give rise to potentially toxic concentrations of numbers of particles. Very high concentrations of oxides of nitrogen may also be generated by gas cooking, and with no extraction and poor ventilation, may reach concentrations at which adverse health effects may be expected. Although respiratory effects of exposure to NOx might be anticipated, recent epidemiology suggests that cardiac effects cannot be excluded, and further investigation of this is desirable.


Keywords: cooking fuels; nitrogen oxides; ultrafine particles PMID:11452045

  7. Evaluating Multipollutant Exposure and Urban Air Quality: Pollutant Interrelationships, Neighborhood Variability, and Nitrogen Dioxide as a Proxy Pollutant

    PubMed Central

    Levy, Ilan; Mihele, Cristian; Lu, Gang; Narayan, Julie; Brook, Jeffrey R.

    2013-01-01

    Background: Although urban air pollution is a complex mix containing multiple constituents, studies of the health effects of long-term exposure often focus on a single pollutant as a proxy for the entire mixture. A better understanding of the component pollutant concentrations and interrelationships would be useful in epidemiological studies that exploit spatial differences in exposure by clarifying the extent to which measures of individual pollutants, particularly nitrogen dioxide (NO2), represent spatial patterns in the multipollutant mixture. Objectives: We examined air pollutant concentrations and interrelationships at the intraurban scale to obtain insight into the nature of the urban mixture of air pollutants. Methods: Mobile measurements of 23 air pollutants were taken systematically at high resolution in Montreal, Quebec, Canada, over 34 days in the winter, summer, and autumn of 2009. Results: We observed variability in pollution levels and in the statistical correlations between different pollutants according to season and neighborhood. Nitrogen oxide species (nitric oxide, NO2, nitrogen oxides, and total oxidized nitrogen species) had the highest overall spatial correlations with the suite of pollutants measured. Ultrafine particles and hydrocarbon-like organic aerosol concentration, a derived measure used as a specific indicator of traffic particles, also had very high correlations. Conclusions: Our findings indicate that the multipollutant mix varies considerably throughout the city, both in time and in space, and thus, no single pollutant would be a perfect proxy measure for the entire mix under all circumstances. However, based on overall average spatial correlations with the suite of pollutants measured, nitrogen oxide species appeared to be the best available indicators of spatial variation in exposure to the outdoor urban air pollutant mixture. Citation: Levy I, Mihele C, Lu G, Narayan J, Brook JR. 2014. Evaluating multipollutant exposure and urban air quality: pollutant interrelationships, neighborhood variability, and nitrogen dioxide as a proxy pollutant. Environ Health Perspect 122:65–72; http://dx.doi.org/10.1289/ehp.1306518 PMID:24225648

  8. Influence of the technique for injection of flue gas and the configuration of the swirl burner throat on combustion of gaseous fuel and formation of nitrogen oxides in the flame

    NASA Astrophysics Data System (ADS)

    Dvoinishnikov, V. A.; Khokhlov, D. A.; Knyaz'kov, V. P.; Ershov, A. Yu.

    2017-05-01

    How the points at which the flue gas was injected into the swirl burner and the design of the burner outlet influence the formation and development of the flame in the submerged space, as well as the formation of nitrogen oxides in the combustion products, have been studied. The object under numerical investigation is the flame of the GMVI combined (oil/gas) burner swirl burner fitted with a convergent, biconical, cylindrical, or divergent throat at the burner outlet with individual supply of the air and injection of the gaseous fuel through tubing. The burners of two designs were investigated; they differ by the absence or presence of an inlet for individual injection of the flue gas. A technique for numerical simulation of the flame based on the CFD methods widely used in research of this kind underlies the study. Based on the summarized results of the numerical simulation of the processes that occur in jet flows, the specific features of the aerodynamic pattern of the flame have been established. It is shown that the flame can be conventionally divided into several sections over its length in all investigations. The lengths of each of the sections, as well as the form of the fields of axial velocity, temperatures, concentrations of the fuel, oxygen, and carbon and nitrogen oxides, are different and determined by the design features of the burner, the flow rates of the agent, and the compositions of the latter in the burner ducts as well as the configuration of the burner throat and the temperature of the environment. To what degree the burner throat configuration and the techniques for injection of the flue gas at different ambient temperatures influence the formation of nitrogen oxides has been established. It is shown that the supply of the recirculation of flue gas into the fuel injection zone enables a considerable reduction in the formation of nitrogen oxides in the flame combustion products. It has been established that the locations of the zones of intensive fuel burnout and generation of nitrogen oxides do not coincide over the flame length, and the ambient temperature has a significant impact on the combustion stability at low values and on the concentration of nitrogen oxides in the combustion products at high values.

  9. Influences of urea and sodium nitrite on surface coating of plasma electrolytic oxidation

    NASA Astrophysics Data System (ADS)

    Yeh, Shang-Chun; Tsai, Dah-Shyang; Guan, Sheng-Yong; Chou, Chen-Chia

    2015-11-01

    Urea and sodium nitrite are generally viewed as nitridation additives in the electrolyte for plasma electrolytic oxidation (PEO) of aluminum alloys. We study the influences of these two convenient chemicals in presence of sodium aluminate and find very different effects on film growth. Urea addition enhances the nitrogen content of PEO layer, diminishes the layer thickness, increases the porosity, interferes with the α-alumina formation, and promotes precipitation in the electrolyte. Hence, the electrolytic urea content ought to be maintained less than 45 g dm-3. On the other hand, sodium nitrite behaves like an oxidation additive, more than a nitridation additive. NaNO2 addition effectively introduces nitrogen in the PEO layer at low concentration, yet the nitrogen content of oxide layer decreases with increasing NaNO2 concentration. The effects of NaNO2, such as increasing layer thickness, reducing porosity, promoting α-alumina formation are attributed to oxidation enhancement, not because of nitridation.

  10. A Generalizable Top-Down Nanostructuring Method of Bulk Oxides: Sequential Oxygen-Nitrogen Exchange Reaction.

    PubMed

    Lee, Lanlee; Kang, Byungwuk; Han, Suyoung; Kim, Hee-Eun; Lee, Moo Dong; Bang, Jin Ho

    2018-05-27

    A thermal reaction route that induces grain fracture instead of grain growth is devised and developed as a top-down approach to prepare nanostructured oxides from bulk solids. This novel synthesis approach, referred to as the sequential oxygen-nitrogen exchange (SONE) reaction, exploits the reversible anion exchange between oxygen and nitrogen in oxides that is driven by a simple two-step thermal treatment in ammonia and air. Internal stress developed by significant structural rearrangement via the formation of (oxy)nitride and the creation of oxygen vacancies and their subsequent combination into nanopores transforms bulk solid oxides into nanostructured oxides. The SONE reaction can be applicable to most transition metal oxides, and when utilized in a lithium-ion battery, the produced nanostructured materials are superior to their bulk counterparts and even comparable to those produced by conventional bottom-up approaches. Given its simplicity and scalability, this synthesis method could open a new avenue to the development of high-performance nanostructured electrode materials that can meet the industrial demand of cost-effectiveness for mass production. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. NO-assisted molecular-beam epitaxial growth of nitrogen substituted EuO

    NASA Astrophysics Data System (ADS)

    Wicks, R.; Altendorf, S. G.; Caspers, C.; Kierspel, H.; Sutarto, R.; Tjeng, L. H.; Damascelli, A.

    2012-04-01

    We have investigated a method for substituting oxygen with nitrogen in EuO thin films, which is based on molecular beam epitaxy distillation with NO gas as the oxidizer. By varying the NO gas pressure, we produce crystalline, epitaxial EuO1 -xNx films with good control over the films' nitrogen concentration. In situ x-ray photoemission spectroscopy reveals that nitrogen substitution is connected to the formation Eu3+4f6 and a corresponding decrease in the number of Eu2+4f7, indicating that nitrogen is being incorporated in its 3- oxidation state. While small amounts of Eu3+ in over-oxidized Eu1-δO thin films lead to a drastic suppression of the ferromagnetism, the formation of Eu3+ in EuO1-xNx still allows the ferromagnetic phase to exist with an unaffected Tc, thus providing an ideal model system to study the interplay between the magnetic f7 (J = 7/2) and the non-magnetic f6 (J = 0) states close to the Fermi level.

  12. DksA-dependent resistance of Salmonella enterica serovar Typhimurium against the antimicrobial activity of inducible nitric oxide synthase.

    PubMed

    Henard, Calvin A; Vázquez-Torres, Andrés

    2012-04-01

    In coordination with the ppGpp alarmone, the RNA polymerase regulatory protein DksA controls the stringent response of eubacteria, negatively regulating transcription of translational machinery and directly activating amino acid promoters and de novo amino acid biosynthesis. Given the effects of nitric oxide (NO) on amino acid biosynthetic pathways and the intimate relationship of DksA with amino acid synthesis and transport, we tested whether DksA contributes to the resistance of Salmonella to reactive nitrogen species (RNS). Our studies show that the zinc finger predicted to position DksA in the secondary channel of the RNA polymerase is essential for the resistance of Salmonella enterica serovar Typhimurium to RNS in a murine model of systemic salmonellosis. Despite exhibiting auxotrophies for various amino acids, ΔdksA mutant Salmonella strains regain virulence in mice lacking inducible NO synthase (iNOS). DksA is also important for growth of this intracellular pathogen in the presence of NO congeners generated by iNOS during the innate response of murine macrophages. Accordingly, dksA mutant Salmonella strains are hypersusceptible to chemically generated NO, a phenotype that can be prevented by adding amino acids. The DksA-dependent antinitrosative defenses do not rely on the Hmp flavohemoprotein that detoxifies NO to NO(3)(-) and appear to operate independently of the ppGpp alarmone. Our investigations are consistent with a model by which NO produced in the innate response to Salmonella exerts considerable pressure on amino acid biosynthesis. The cytotoxicity of NO against Salmonella amino acid biosynthetic pathways is antagonized in great part by the DksA-dependent regulation of amino acid biosynthesis and transport.

  13. Oxidative damage in DNA bases revealed by UV resonant Raman spectroscopy.

    PubMed

    D'Amico, Francesco; Cammisuli, Francesca; Addobbati, Riccardo; Rizzardi, Clara; Gessini, Alessandro; Masciovecchio, Claudio; Rossi, Barbara; Pascolo, Lorella

    2015-03-07

    We report on the use of the UV Raman technique to monitor the oxidative damage of deoxynucleotide triphosphates (dATP, dGTP, dCTP and dTTP) and DNA (plasmid vector) solutions. Nucleotide and DNA aqueous solutions were exposed to hydrogen peroxide (H2O2) and iron containing carbon nanotubes (CNTs) to produce Fenton's reaction and induce oxidative damage. UV Raman spectroscopy is shown to be maximally efficient to reveal changes in the nitrogenous bases during the oxidative mechanisms occurring on these molecules. The analysis of Raman spectra, supported by numerical computations, revealed that the Fenton's reaction causes an oxidation of the nitrogenous bases in dATP, dGTP and dCTP solutions leading to the production of 2-hydroxyadenine, 8-hydroxyguanine and 5-hydroxycytosine. No thymine change was revealed in the dTTP solution under the same conditions. Compared to single nucleotide solutions, plasmid DNA oxidation has resulted in more radical damage that causes the breaking of the adenine and guanine aromatic rings. Our study demonstrates the advantage of using UV Raman spectroscopy for rapidly monitoring the oxidation changes in DNA aqueous solutions that can be assigned to specific nitrogenous bases.

  14. Nitrogen Doped Graphene Supported Pt Nanoflowers as Electrocatalysts for Oxidation of Formaldehyde.

    PubMed

    Xie, Aijuan; Zhou, Wenting; Luo, Shiping; Chen, Yu; Zhou, Xiaoqing; Chao, Yao

    2017-02-01

    A facile Pt nanoflowers/nitrogen-doped graphene (PtNFs/NG) electrocatalyst was prepared via depositing Pt nanoflowers (PtNFs) onto the nitrogen-doped graphene (NG) matrix with urea as the nitrogen source and PtNFs/NG modified glassy carbon electrode (GCE) was prepared by electro-chemical method. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Raman spectroscope, X-ray photoelectron spectroscopy (XPS) and Scanning electron microscope (SEM) were used to characterize the resulting composites. Also oxidation of formaldehyde on the resulting PtNFs/NG modified electrode was investigated. The influence of deposition time, electrodeposition potential and formaldehyde concentration on electrooxidation of formaldehyde was detected, the experimental results indicate the high performance of PtNFs/NG catalyst for formaldehyde oxidation is at electrodeposition time of 300 s with the applied potential of −0.3 V. Electrochemical process, electrocatalytic stability and chronoamperometry were also inspected, it was indicated that formalde-hyde oxidation reaction on the PtNFs/NG electrode is diffusion-controlled and PtNFs/NG exhibits a high catalytic activity, stability as well as excellent poisoning-tolerance towards formaldehyde oxidation, which is attributed to the synergistic effect of PtNFs and NG. It turns out that PtNFs/NG can be used in direct liquid-feed fuel cells as a promising alternative catalyst.

  15. Novel two stage bio-oxidation and chlorination process for high strength hazardous coal carbonization effluent.

    PubMed

    Manekar, Pravin; Biswas, Rima; Karthik, Manikavasagam; Nandy, Tapas

    2011-05-15

    Effluent generated from coal carbonization to coke was characterized with high organic content, phenols, ammonium nitrogen, and cyanides. A full scale effluent treatment plant (ETP) working on the principle of single stage carbon-nitrogen bio-oxidation process (SSCNBP) revealed competition between heterotrophic and autotrophic bacteria in the bio-degradation and nitrification process. The effluent was pretreated in a stripper and further combined with other streams to treat in the SSCNBP. Laboratory studies were carried on process and stripped effluents in a bench scale model of ammonia stripper and a two stage bio-oxidation process. The free ammonia removal efficiency of stripper was in the range 70-89%. Bench scale studies of the two stage bio-oxidation process achieved a carbon-nitrogen reduction at 6 days hydraulic retention time (HRT) operating in an extended aeration mode. This paper addresses the studies on selection of a treatment process for removal of organic matter, phenols, cyanide and ammonia nitrogen. The treatment scheme comprising ammonia stripping (pretreatment) followed by the two stage bio-oxidation and chlorination process met the Indian Standards for discharge into Inland Surface Waters. This treatment process package offers a techno-economically viable treatment scheme to neuter hazardous effluent generated from coal carbonization process. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Assessment of nitrogen and oxygen isotopic fractionation during nitrification and its expression in the marine environment.

    PubMed

    Casciotti, Karen L; Buchwald, Carolyn; Santoro, Alyson E; Frame, Caitlin

    2011-01-01

    Nitrification is a microbially-catalyzed process whereby ammonia (NH(3)) is oxidized to nitrite (NO(2)(-)) and subsequently to nitrate (NO(3)(-)). It is also responsible for production of nitrous oxide (N(2)O), a climatically important greenhouse gas. Because the microbes responsible for nitrification are primarily autotrophic, nitrification provides a unique link between the carbon and nitrogen cycles. Nitrogen and oxygen stable isotope ratios have provided insights into where nitrification contributes to the availability of NO(2)(-) and NO(3)(-), and where it constitutes a significant source of N(2)O. This chapter describes methods for determining kinetic isotope effects involved with ammonia oxidation and nitrite oxidation, the two independent steps in the nitrification process, and their expression in the marine environment. It also outlines some remaining questions and issues related to isotopic fractionation during nitrification. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Outcompeting nitrite-oxidizing bacteria in single-stage nitrogen removal in sewage treatment plants: a model-based study.

    PubMed

    Pérez, Julio; Lotti, Tommaso; Kleerebezem, Robbert; Picioreanu, Cristian; van Loosdrecht, Mark C M

    2014-12-01

    This model-based study investigated the mechanisms and operational window for efficient repression of nitrite oxidizing bacteria (NOB) in an autotrophic nitrogen removal process. The operation of a continuous single-stage granular sludge process was simulated for nitrogen removal from pretreated sewage at 10 °C. The effects of the residual ammonium concentration were explicitly analyzed with the model. Competition for oxygen between ammonia-oxidizing bacteria (AOB) and NOB was found to be essential for NOB repression even when the suppression of nitrite oxidation is assisted by nitrite reduction by anammox (AMX). The nitrite half-saturation coefficient of NOB and AMX proved non-sensitive for the model output. The maximum specific growth rate of AMX bacteria proved a sensitive process parameter, because higher rates would provide a competitive advantage for AMX. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Exhaust emission calibration of two J-58 afterburning turbojet engines at simulated high-altitude, supersonic flight conditions

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.

    1976-01-01

    Emissions of total oxides of nitrogen, nitric oxide, unburned hydrocarbons, carbon monoxide, and carbon dioxide from two J-58 afterburning turbojet engines at simulated high-altitude flight conditions are reported. Test conditions included flight speeds from Mach 2 to 3 at altitudes from 16.0 to 23.5 km. For each flight condition exhaust measurements were made for four or five power levels, from maximum power without afterburning through maximum afterburning. The data show that exhaust emissions vary with flight speed, altitude, power level, and radial position across the exhaust. Oxides of nitrogen emissions decreased with increasing altitude and increased with increasing flight speed. Oxides of nitrogen emission indices with afterburning were less than half the value without afterburning. Carbon monoxide and hydrocarbon emissions increased with increasing altitude and decreased with increasing flight speed. Emissions of these species were substantially higher with afterburning than without.

  19. Nitrous oxide flux and nitrogen transformations across a landscape gradient in Amazonia

    NASA Technical Reports Server (NTRS)

    Livingston, Gerald P.; Vitousek, Peter M.; Matson, Pamela A.

    1988-01-01

    Nitrous oxide flux and nitrogen turnover were measured in three types of Amazonian forest ecosystems within Reserva Florestal Ducke near Manaus, Brazil. Nitrogen mineralization and nitrate production measured during 10-day laboratory incubations were 3-4 times higher in clay soils associated with 'terra firme' forests on ridge-top and slope positions than in 'campinarana' forests on bottomland sand soils. In contrast, nitrous oxide fluxes did not differ significantly among sites, but were highly variable in space and time. The observed frequency distribution of flux was positively skewed, with a mean overall sites and all sampling times of 1.3 ng N2O-N/sq cm per hr. Overall, the flux estimates were comparable to or greater than those of temperature forests, but less than others reported for Amazoonia. Results from a field fertilization experiment suggest that most nitrous oxide flux was associated with denitrification of soil nitrate.

  20. Criteria pollutant and greenhouse gas emissions from CNG transit buses equipped with three-way catalysts compared to lean-burn engines and oxidation catalyst technologies.

    PubMed

    Yoon, Seungju; Collins, John; Thiruvengadam, Arvind; Gautam, Mridul; Herner, Jorn; Ayala, Alberto

    2013-08-01

    Engine and exhaust control technologies applied to compressed natural gas (CNG) transit buses have advanced from lean-burn, to lean-burn with oxidation catalyst (OxC), to stoichiometric combustion with three-way catalyst (TWC). With this technology advancement, regulated gaseous and particulate matter emissions have been significantly reduced. Two CNG transit buses equipped with stoichiometric combustion engines and TWCs were tested on a chassis dynamometer, and their emissions were measured. Emissions from the stoichiometric engines with TWCs were then compared to the emissions from lean-burn CNG transit buses tested in previous studies. Stoichiometric combustion with TWC was effective in reducing emissions of oxides of nitrogen (NO(x)), particulate matter (PM), and nonmethane hydrocarbon (NMHC) by 87% to 98% depending on pollutants and test cycles, compared to lean combustion. The high removal efficiencies exceeded the emission reduction required from the certification standards, especially for NO(x) and PM. While the certification standards require 95% and 90% reductions for NO(x) and PM, respectively, from the engine model years 1998-2003 to the engine model year 2007, the measured NO(x) and PM emissions show 96% and 95% reductions, respectively, from the lean-burn engines to the stoichiometric engines with TWC over the transient Urban Dynamometer Driving Schedule (UDDS) cycle. One drawback of stoichiometric combustion with TWC is that this technology produces higher carbon monoxide (CO) emissions than lean combustion. In regard to controlling CO emissions, lean combustion with OxC is more effective than stoichiometric combustion. Stoichiometric combustion with TWC produced higher greenhouse gas (GHG) emissions including carbon dioxide (CO2) and methane (CH4) than lean combustion during the UDDS cycle, but lower GHG emissions during the steady-state cruise cycle. Stoichiometric combustion with three-way catalyst is currently the best emission control technology available for compressed natural gas (CNG) transit buses to meet the stringent U.S. Environmental Protection Agency (EPA) 2010 heavy-duty engine NO(x) emissions standard. For existing lean-burn CNG transit buses in the fleet, oxidation catalyst would be the most effective retrofit technology for the control of NMHC and CO emissions.

  1. Quantifying atmospheric nitrogen outflow from the Front Range of Colorado

    NASA Astrophysics Data System (ADS)

    Neuman, J. A.; Eilerman, S. J.; Brock, C. A.; Brown, S. S.; Dube, W. P.; Herndon, S. C.; Holloway, J. S.; Nowak, J. B.; Roscioli, J. R.; Ryerson, T. B.; Sjostedt, S. J.; Thompson, C. R.; Trainer, M.; Veres, P. R.; Wild, R. J.

    2015-12-01

    Reactive nitrogen emitted to the atmosphere from urban, industrial, and agricultural sources can be transported and deposited far from the source regions, affecting vegetation, soils, and water of sensitive ecosystems. Mitigation of atmospheric nitrogen deposition requires emissions characterization and quantification. Ammonia (NH3), a full suite of gas-phase oxidized nitrogen compounds, and particulate matter were measured from an aircraft that flew downwind from concentrated animal feeding operations, oil and gas extraction facilities, and urban areas along the Colorado Front Range in March and April 2015, as part of the Shale Oil and Natural Gas Nexus (SONGNEX) field study. Additionally, NH3 measurements from a fully instrumented aircraft that flew over the same region in July and August 2014 as part of the Front Range Air Pollution and Photochemistry Experiment (FRAPPE) are used to examine atmospheric nitrogen emission and transport. Cross-wind plume transects and altitude profiles were performed over the source regions and 60-240 km downwind. Plumes were transported in the boundary layer with large NH3 mixing ratios (typically 20-100 ppbv) and were tens of km wide. The NH3 in these plumes provided an atmospheric nitrogen burden greater than 0.2 kg N/ha. Nitrogen oxides and their oxidation products and particulate matter were also enhanced in the plumes, but with concentrations substantially less than NH3. With efficient transport followed by wet deposition, these plumes have the potential to provide a large nitrogen input to the neighboring Rocky Mountain National Park, where nitrogen deposition currently exceeds the ecological critical load of 1.5 kg N/ha/yr.

  2. Long-term tillage and nitrogen fertilization in maize influences the ammonia-oxidizing bacterial community

    USDA-ARS?s Scientific Manuscript database

    Nitrification is a biological oxidation of NH3 to NO2- and then to NO3-. Managing nitrifiers to increase nitrogen (N) fertilizer use efficiency, decrease NO3- leaching, and reduce NO and N2O emissions could benefit the environment. But one must first understand the structure of the nitrifier communi...

  3. The Load of Lightning-induced Nitrogen Oxides and Its Impact on the Ground-level Ozone during Summertime over the Mountain West States

    EPA Science Inventory

    Lightning-induced nitrogen oxides (LNOX), in the presence of sunlight, volatile organic compounds and water, can be a relatively large but uncertain source for ozone (O3) and hydroxyl radical (OH) in the atmosphere. Using lightning flash data from the National Lightning Detection...

  4. OBSERVATION-BASED ASSESSMENT OF THE IMPACT OF NITROGEN OXIDES EMISSIONS REDUCTIONS ON OZONE AIR QUALITY OVER THE EASTERN UNITED STATES

    EPA Science Inventory

    Ozone is produced by chemical interactions involving nitrogen oxides (NOx) and Volatile Organic Compounds (VOCs) in the presence of sunlight. At high concentrations, ground-level ozone has been shown to be harmful to human health and the environment. It has been reco...

  5. Nitrous oxide emissions from a golf course fairway and rough following application of different nitrogen fertilizers

    USDA-ARS?s Scientific Manuscript database

    Nitrous oxide (N2O) is a potent greenhouse gas that destroys stratospheric ozone. There is limited research of golf course N2O emission and the effects of frequent fertilization and irrigation. Three enhanced efficiency nitrogen fertilizers (EENFs) were applied to a Colorado golf course fairway and ...

  6. 40 CFR 60.45Da - Alternative standards for combined nitrogen oxides (NOX) and carbon monoxide (CO).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Alternative standards for combined nitrogen oxides (NOX) and carbon monoxide (CO). 60.45Da Section 60.45Da Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for...

  7. 40 CFR 60.45Da - Alternative standards for combined nitrogen oxides (NOX) and carbon monoxide (CO).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Alternative standards for combined nitrogen oxides (NOX) and carbon monoxide (CO). 60.45Da Section 60.45Da Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for...

  8. 40 CFR 60.45Da - Alternative standards for combined nitrogen oxides (NOX) and carbon monoxide (CO).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Alternative standards for combined nitrogen oxides (NOX) and carbon monoxide (CO). 60.45Da Section 60.45Da Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for...

  9. Production of nitrogen oxides in air pulse-periodic discharge with apokamp

    NASA Astrophysics Data System (ADS)

    Panarin, Victor A.; Skakun, Victor S.; Sosnin, Eduard A.; Tarasenko, Victor F.

    2018-05-01

    The decomposition products of pulse-periodic discharge atmospheric pressure plasma in apokamp, diffuse and corona modes were determined by optical and chemical methods. It is shown that apokamp discharge formation starts at a critical value of dissipation power in a discharge channel. Simultaneously, due to the thermochemical reactions, plasma starts to efficiently produce nitrogen oxides.

  10. One-step electrochemical synthesis of nitrogen and sulfur co-doped, high-quality graphene oxide.

    PubMed

    Parvez, Khaled; Rincón, Rosalba A; Weber, Nils-Eike; Cha, Kitty C; Venkataraman, Shyam S

    2016-04-28

    High-quality graphene oxide (GO) with high crystallinity and electrical conductivity as well as in situ doped with nitrogen and sulfur is obtained via the electrochemical exfoliation of graphite. Furthermore, iron incorporated GO sheets show promising catalytic activity and stable methanol tolerance durability when used as electrocatalysts for the oxygen reduction reaction.

  11. 40 CFR 52.184 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.184 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a) The owner and...

  12. 40 CFR 52.2540 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2540 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  13. 40 CFR 52.1930 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1930 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a) The...

  14. 40 CFR 52.54 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.54 Section 52.54... FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and operator of each...

  15. 40 CFR 52.1084 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1084 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  16. 40 CFR 52.484 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.484 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  17. 40 CFR 52.1784 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1784 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  18. 40 CFR 52.789 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.789 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  19. 40 CFR 52.984 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.984 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  20. 40 CFR 52.584 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.584 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  1. 40 CFR 52.840 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.840 Section 52...; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  2. 40 CFR 52.2440 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2440 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  3. 40 CFR 52.731 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.731 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  4. 40 CFR 52.1326 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1326 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  5. 40 CFR 52.1284 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1284 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a) The...

  6. 40 CFR 52.2040 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2040 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  7. 40 CFR 52.840 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.840 Section 52...; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  8. 40 CFR 52.1584 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1584 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  9. 40 CFR 52.2283 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2283 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  10. 40 CFR 52.540 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.540 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a) The owner and...

  11. 40 CFR 52.984 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.984 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  12. 40 CFR 52.1084 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1084 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  13. 40 CFR 52.1584 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1584 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  14. 40 CFR 52.2240 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2240 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  15. 40 CFR 52.1882 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.1882 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  16. 40 CFR 52.2283 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.2283 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  17. 40 CFR 52.484 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.484 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  18. 40 CFR 52.484 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.484 Section 52... transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1...

  19. 40 CFR 52.584 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.584 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

  20. 40 CFR 52.440 - Interstate pollutant transport provisions; What are the FIP requirements for decreases in...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Interstate pollutant transport provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? 52.440 Section 52... provisions; What are the FIP requirements for decreases in emissions of nitrogen oxides? (a)(1) The owner and...

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