Ground-level Ozone Formation Research Articles

Effects of ship emissions on European ground-level ozone in 2020

In recent decades land-based emissions of air pollutants have been substantially reduced over Europe. At the same time emissions from shipping have continued to grow globally. Emissions from international shipping in sea areas surrounding Europe now contribute about 30% of the EU27 emissions of sulphur and NOx and affect ozone levels all over Europe. Although ozone levels are expected to decrease in most parts of Europe, prognoses for 2020 levels are still above what is considered as threshold values. A growing portion of these impacts can be attributed to emissions from international shipping. This paper presents an evaluation of the impacts on ozone levels in the European mainland due to emissions from international shipping. Calculations are carried out under recent (2004) conditions and for a scenario in 2020, where further emission reductions are applied to land based emissions while the ships emissions increase according to their expected growth in transport volumes, without additional technical reduction measures. Impacts are considered with respect to the formation of ground-level ozone, presented as somo35. We investigate the effect of different shipping emission sources, in particular, international shipping inside the 12 mile zone from the coast, emissions from ships outside the 12 mile zone with EU flags and emissions from ships under other flags. It is shown that contributions from EU ships and non-EU and ships outside the 12 mile zone are about equal in magnitude. Corrected for source strength, the largest effect relative to source strength is from emissions within the 12 mile zone. Here ozone titration may cause reductions in somo35 of more than 10% in some countries, or increases of 5% or more elsewhere.

Transport impacts on atmosphere and climate: Shipping

Emissions of exhaust gases and particles from oceangoing ships are a significant and growing contributor to the total emissions from the transportation sector. We present an assessment of the contribution of gaseous and particulate emissions from oceangoing shipping to anthropogenic emissions and air quality. We also assess the degradation in human health and climate change created by these emissions. Regulating ship emissions requires comprehensive knowledge of current fuel consumption and emissions, understanding of their impact on atmospheric composition and climate, and projections of potential future evolutions and mitigation options. Nearly 70% of ship emissions occur within 400 km of coastlines, causing air quality problems through the formation of ground-level ozone, sulphur emissions and particulate matter in coastal areas and harbours with heavy traffic. Furthermore, ozone and aerosol precursor emissions as well as their derivative species from ships may be transported in the atmosphere over several hundreds of kilometres, and thus contribute to air quality problems further inland, even though they are emitted at sea. In addition, ship emissions impact climate. Recent studies indicate that the cooling due to altered clouds far outweighs the warming effects from greenhouse gases such as carbon dioxide (CO 2) or ozone from shipping, overall causing a negative present-day radiative forcing (RF). Current efforts to reduce sulphur and other pollutants from shipping may modify this. However, given the short residence time of sulphate compared to CO 2, the climate response from sulphate is of the order decades while that of CO 2 is centuries. The climatic trade-off between positive and negative radiative forcing is still a topic of scientific research, but from what is currently known, a simple cancellation of global mean forcing components is potentially inappropriate and a more comprehensive assessment metric is required. The CO 2 equivalent emissions using the global temperature change potential (GTP) metric indicate that after 50 years the net global mean effect of current emissions is close to zero through cancellation of warming by CO 2 and cooling by sulphate and nitrogen oxides.

Sensors for Environmental Compliance of Diesel Engines

Nitrogen oxides generated from the combustion of fossil fuels contribute to ground level ozone formation and acid rain deposition. To minimize emissions the robust sensor technologies required. Solid-state electrochemical NOx and NH3 sensors evaluated in this study showed significant cross-interference issues. In contrast, the semiconductor nanowires of Cu and Pb Pthtalocyanine and CdS thin films functionalized with Fe and Mn Porphyrines (Ph) exhibited negligible cross-interferences. The computational molecular modeling was utilized to analyze equilibrium structures and binding energies of O2, CO, NO, NH3, and these were shown to control the selectivity. The FePh exhibited the highest selectivity for NO (-190 kJ/mol), while MnPh was most selective to NH3 (-46.7 kJ/mol). The binding energies of gas molecules to the hybrid Ph-CdS system were approximately 30 kJ/mol greater than binding to the Ph alone. Therefore, the semiconductor surface buried under the Ph layer enhanced sensitivity, but it did not alter the selectivity.

A review on the use of gas and steam turbine combined cycles as prime movers for large ships. Part I: Background and design

The aim of the present paper is to review the prospects of using combined cycles as prime movers for large ships, like, container ships, tankers and bulk carriers. The paper is divided into three parts of which this paper constitutes Part I. Here, the environmental and human health concerns of international shipping are outlined. The regulatory framework relevant for shipping and the design of combined cycles are discussed. In Part II, previous work and experience are reviewed, and an overview of the implications of introducing combined cycles as prime movers is included. In Part III, marine fuels are discussed and the pollutant emissions of gas turbines are compared with those of two-stroke, slow-speed diesel engines. Environmental effects of shipping include contributions to the formation of ground-level ozone, acidification, eutrophication and climate impact. Tightening environmental regulations limit the fuel sulphur content and pollutant emissions. For moderate live steam pressures, a vertical HRSG of drum-type mounted directly over the gas turbine, is suggested to be a viable configuration that minimizes ground floor and space requirements.

Assessment of the Ozone Formation Potential from Pesticide Solvents Using a Mobile Ozone Chamber Assay Approach

Abstract The use of pesticides in California’s agricultural industry plays a role in air quality with emissions of organic compounds thought to contribute to the formation of ground level ozone. Ozone levels in many regions of California exceed the prescribed Federal and State standards every year. The actual contribution from pesticide applications (as well as other agricultural sources) is largely unknown, and relies on assumptions of reactivity and tendency to evaporate. Progress on accurate determinations of either parameter is limited by many factors, including the proprietary nature of formulations. We have developed an approach which can measure the ozone formation potential of many agricultural sources, in the field. This approach was previously validated and described during a recently completed and published study of emissions from dairy cattle, their feed, as well as their fresh waste. With accompanying measurements of the most abundant volatile organic compounds (VOCs) involved there, we showed agreement between laboratory studies, field measurements, and a computer model of atmospheric photochemical reactions that improves upon past efforts, which were limited to urban/industrial VOCs. Our goal is to reach the same level of understanding for VOCs contained in pesticide formulations. Two sets of field experiments were performed to assess the ozone formation potential of pesticide solvents using a set of transportable smog chambers in the summer of 2007. The first set of experiments were conducted for a solvent-based emulsifiable concentrate (EC) base-spray on a one-acre bare field, and the second set of experiments were conducted for an agricultural application of Lorsban 4E in a three-acre citrus orchard. By comparing the upwind and downwind measurements, the experiments indicated that the emission of pesticide solvent after field application led to increased ozone formation. After a 180 min UV exposure, the ozone formation potential measured at the downwind side averaged 14 ppb higher than that of upwind air, while the average difference was around 3 ppb for background levels on both the day before and the day after pesticide spray. Laboratory experiments were also conducted for different doses of EC base with various levels of nitrogen oxides using the transportable smog chambers. The experimental isopleth demonstrates that VOCs emitted from the EC base could result in high ozone formation. Future work will provide full VOC speciation and application of the results in a regional photochemical model to predict ozone impacts.

Volatile organic compounds emitted from hardwood drying as a function of processing parameters

During the drying of wood, volatile organic compounds are emitted. These emissions contribute, in the presence of nitrogen oxides and sunlight, to the formation of ground level ozone and other harmful photo-oxidants. Emissions of volatile organic compounds from the drying of birch sawdust in a spouted bed were analyzed with a flame ionization detector and with a gas chromatograph-mass spectrometer. A D-optimal model of the emissions showed that the emissions increased exponentially with decreasing sawdust moisture content and that the final sawdust moisture content was influencing emissions about twice as much as the inlet drying medium temperature and the month of logging. At inlet temperatures of 140–170 °C, the emissions increased steeply when the moisture content of the sawdust reached 10%, whereas an inlet temperature of 200 °C caused a surge of thermal degradation products at 15% moisture content. The results of this study should help to reduce the emissions of volatile hydrocarbons during the drying of hardwood sawdust and wood chips.

Evaluation of Fumigation and Surface Seal Methods on Fumigant Emissions in an Orchard Replant Field

Soil fumigation is an important management practice for controlling soil pests and enabling successful replanting of orchards. Reducing emissions is required to minimize the possible worker and bystander risk and the contribution of fumigants to the atmosphere as volatile organic compounds that lead to the formation of ground-level ozone. A field trial was conducted in a peach orchard replant field to investigate the effects of fumigation method (shank-injection vs. subsurface drip-application treatments) and surface treatments (water applications and plastic tarps) on emissions of 1,3-dichloropropene (1,3-D) and chloropicrin (CP) from shank-injection of Telone C-35 and drip application of InLine. Treatments included control (no water or soil surface treatment); standard high-density polyethylene (HDPE) tarp, virtually impermeable film (VIF) tarp, and pre-irrigation, all over shank injection; and HDPE tarp over and irrigation with micro-sprinklers before and after the drip application. The highest 1,3-D and CP emission losses over a 2-wk monitoring period were from the control (36% 1,3-D and 30% CP) and HDPE tarp (43% 1,3-D and 17% CP) over shank injection. The pre-irrigation 4 d before fumigation and VIF tarp over shank injection had similar total emission losses (19% 1,3-D and 8-9% CP). The HDPE tarp and irrigations over subsurface drip-application treatments resulted in similar and the lowest emission losses (12-13% 1,3-D, and 2-3% CP). Lower fumigant concentrations in the soil-gas phase were observed with drip-application than in the shank-injection treatments; however, all treatments provided 100% kill to citrus nematodes in bags buried from 30 to 90 cm depth. Pre-irrigation and drip application seem to be effective to minimize emissions of 1,3-D and CP.

Ground-level ozone in the Pearl River Delta and the roles of VOC and NO x in its production

In many regions of China, very rapid economic growth has been accompanied by air pollution caused by vehicle emissions. In one of these regions, the Pearl River Delta, the variations of ground-level ozone and its precursors were investigated. Overall, the ambient concentrations of NO 2 increased quickly between 1995 and 1996, but then slightly decreased due to stringent nitrogen oxide (NO x ) emission controls. Nonetheless, ambient NO 2 levels in the Pearl River Delta remained high. The regional average concentrations of volatile organic compounds (VOCs) were 290 ppbC in summer and 190 ppbC in autumn. Local emissions and long-distance transportation of pollutants play important roles in the regional distribution of VOCs. Ambient O 3 production is significant in urban areas and also downwind of cities. The relative incremental reactivities (RIRs), determined by an observation-based model, showed that ground-level ozone formation in the Guangzhou urban area is generally limited by the concentrations of VOCs, but there are also measurable impacts of NO x .

Development of a Framework for Quantifying the Environmental Impacts of Urban Development and Construction Practices

To encourage sustainable development, engineers and scientists need to understand the interactions among social decision-making, development and redevelopment, land, energy and material use, and their environmental impacts. In this study, a framework that connects these interactions was proposed to guide more sustainable urban planning and construction practices. Focusing on the rapidly urbanizing setting of Phoenix, Arizona, complexity models and deterministic models were assembled as a metamodel, which is called Sustainable Futures 2100 and were used to predict land use and development, to quantify construction material demands, to analyze the life cycle environmental impacts, and to simulate future ground-level ozone formation.

Source Apportionment of Ambient Volatile Organic Compounds in Beijing

The ambient air quality standard for ozone is frequently exceeded in Beijing in summer and autumn. Source apportionments of volatile organic compounds (VOCs), which are precursors of ground-level ozone formation, can be helpful to the further study of tropospheric ozone formation. In this study, ambient concentrations of VOCs were continuously measured with a time resolution of 30 min in August 2005 in Beijing. By using positive matrix factorization (PMF), eight sources for the selected VOC species were extracted. Gasoline-related emissions (the combination of gasoline exhaust and gas vapor), petrochemicals, and liquefied petroleum gas (LPG) contributed 52, 20, and 11%, respectively, to total ambient VOCs. VOC emissions from natural gas (5%), painting (5%), diesel vehicles (3%), and biogenic emissions (2%) were also identified. The gasoline-related, petrochemical, and biogenic sources were estimated to be the major contributors to ozone formation potentials in Beijing.

SELECTIVE CATALYTIC REDUCTION AS A SECONDARY METHOD TO REMOVE NOx FROM DIESEL ENGINE EXHAUST GAS

The exhaust emissions from large marine diesel engines on ocean going vessels contains among other pollutants a significant amount of Nitrogen Oxides (NOx) wich are the main byproduct of combustion and they contribute to acid rain as well as the formation of harmful ground-level ozone and photochemical smog. The manufacturers of the marine vessel engines and the shipbuilders have responded to the demands to reduce vessel emissions by improving the operation of the engines and by incorporating emissions control technologies in the design of new vessels. Selective Catalytic Reduction (SCR), fuel emulsions, water injection systems and a number of engine modifications are a sample of the technologies being employed. The challenge is to control NOx emissions without increasing fuel consumption and smoke. An SCR (Selective Catalytic Reduction) unit is an effective means of conditioning the exhaust gas after the combustion process for reducing NOx already formed in the combustion process. The process essentially involves injecting ammonia in the exhaust stream and in the presence of a catalyst the NOx reacts with the ammonia and forms water vapor and nitrogenThis paper describes method to remove nitrogen oxides from exhaust gas of the slow speed marine diesel propulsion engine B&W-5L90MC using selective catalytic reduction (SCR). The efficiency of the SCR system was tested on engine room full mission simulator Kongsberg ERS-L11 MAN B&W-5L90MC—VLCC Version MC90-IV which is installed on Faculty of Maritime studies in Split. The results are illustrated by figures and graphs which shows a 95% NOx reduction in exhaust gas afer has been treated trought SCR reactor.

Evaluation of ogawa passive sampling devices as an alternative measurement method for the nitrogen dioxide annual standard in El Paso, Texas

Nitrogen Dioxide (NO(2)) is a common urban air pollutant that results from the combustion of fossil fuels. It causes serious human health effects, is a precursor to the formation of ground level ozone, another serious air pollutant, and is one of the six criteria air pollutants established by the United States (U.S.) Clean Air Act (CAA). Ogawa Passive Sampling Devices (PSDs) for NO(2) were collocated and operated at six NO(2) Federal Reference Method (FRM) monitor locations in the El Paso, Texas area for the 2004 calendar year. Passive samples were taken at 2-week, 3-week, and 4-week intervals and compared against the continuously operating FRM monitors. Results showed that the collective NO(2) annual arithmetic mean for all passive monitors was identical to the NO(2) mean for all FRM monitors. Of the individual locations, three passive annual NO(2) means were identical to their corresponding FRM means, and three passive annual NO(2) means differed from their corresponding FRM means by only one part per billion (ppb). Linear correlation analysis between all readings of the individual NO(2) PSDs and FRM values showed an average absolute difference of 1.2 ppb with an r (2) of 0.95. Paired comparison between high and low concentration annual NO(2) sites, seasonal considerations, and interlab quality control comparisons all showed excellent results. The ease of deployment, reliability, and the cost-savings that can be realized with NO(2) PSDs could make them an attractive alternative to FRM monitors for screening purposes, and even possibly an equivalent method for annual NO(2) monitoring. More tests of the Ogawa NO(2) PSD are recommended for different ecosystem and climate regimes.

Air Quality Management Using Modern Remote Sensing and Spatial Technologies and Associated Societal Costs

This paper presents a study of societal costs related to public health due to the degradation of air quality and the lack of physical activity, both affected by our built environment. The paper further shows road safety as another public health concern. Traffic fatalities are the number one cause of death in the world. Traffic accidents result in huge financial loss to the people involved and the related public health cost is a significant part of the total societal cost. Motor vehicle exhausts and industrial emissions, gasoline vapors, and chemical solvents as well as natural sources emit nitrogen oxides and volatile organic compounds, which are precursors to the formation of ground-level Ozone. High concentration values of ground-level Ozone in hot summer days produce smog and lead to respiratory problems and loss in worker's productivity. These factors and associated economic costs to society are important in establishing public policy and decision-making for sustainable transportation and development of communities in both industrialized and developing countries. This paper presents new science models for predicting ground-level Ozone and related air quality degradation. The models include predictor variables of daily climatological data, traffic volume and mix, speed, aviation data, and emission inventory of point sources. These models have been implemented in the user friendly AQMAN computer program and used for a case study in Northern Mississippi. Lifecycle benefits from reduced societal costs can be used to implement sustainable transportation policies, enhance investment decision-making, and protect public health and the environment.

Sensitivity analysis of ground-level ozone concentration to emission changes in two urban regions of southeast Texas

Air pollutant emission is one of the predominant factors affecting urban air quality such as ground-level ozone formation. This paper assesses the impact of changing emission inventory scenarios, based on combinations of point, mobile, area/non-road and biogenic sources, on the tropospheric ozone concentration in two southeast Texas urban areas, i.e. Houston-Galveston and Beaumont-Port Arthur, during the rapid ozone formation event (ROFE) on August 25, 2000. The EPA's Community Multiscale Air Quality (CMAQ) modeling system with 1999 national emission inventory (NEI99) estimates and updated SAPRC99 chemical mechanism are used in the sensitivity analysis for twelve different emission scenarios. Based on model results, it is found that the point source emission of NO x and VOC contributes the greatest ozone peak in the ROFE. Removing Texas point sources of VOC and NO x emission from the inventory results in a reduction in peak O 3 concentration by 128 and 70 ppbv in Houston urban area, respectively. Similar but less drastic impact from point source is also observed in the Beaumont-Port Arthur area. The effect on peak ozone concentration due to mobile, area and non-road sources emissions are less significant compared to that of point source emission. Reducing VOC emission appears to be more effective than reducing NO x emission in lowering peak O 3 concentration in the studied region. Although biogenic emission can contribute up to 37 ppbv of peak ozone level over a large area, the affected area is away from the urban region of concern, and should not be the main cause for O 3 non-attainment in the two urban areas. Removing CO emission from mobile sources does not lead to significant reduction (<1 ppbv) in ozone concentrations. The modeled data also show that the transport of O 3 precursors from adjacent states can cause a significant ozone plume near Beaumont due to its proximity to the state border based on the conditions during the August 25, 2000 O 3 episode.

Impact of the leakage of liquefied petroleum gas (LPG) on Santiago Air Quality

The leakage of unburned liquefied petroleum gas (LPG) is a major source of urban nonmethane hydrocarbons (NMHCs) in the air of Santiago, Chile. Roughly 5% of the LPG that is sold in Santiago leaks in its unburned form to the atmosphere. Because of the leakage, propane is the most abundant NMHC in Santiago's air, even under heavy traffic conditions. NMHCs are an important precursor to the formation of ground‐level ozone, and the LPG leakage may contribute as much as 15% to the excess ozone levels in Santiago. Improvement to the local air quality may be obtained by lowering the rates of LPG leakage, and by minimizing the use of alkene‐rich LPG formulations.

Application of the Urban Airshed Model to Forecasting Next-Day Peak Ozone Concentrations in Atlanta, Georgia

ABSTRACT Twenty-four to forty-eight-hour ozone air quality forecasts are increasingly being used in metropolitan areas to inform the public about potentially harmful air quality conditions. The forecasts are also behind “ozone action day” programs in which the public and private sectors are encouraged or mandated to alter activities that contribute to the formation of ground-level ozone. Presented here is a low-cost application of the Urban Airshed Model (UAM), an Eulerian 3-dimensional photochemical-transport grid model for generating next-day peak ozone concentration forecasts. During the summer of 1997, next-day peak ozone concentrations in Atlanta, GA, were predicted both by a team of eight forecasters and by the Urban Airshed Model in Forecast Mode (UAM-FM). Results are presented that compare the accuracy of the team and the UAM-FM. The results for the summer of 1997 indicate that the UAM-FM may be a better predictor of peak ozone concentrations when concentrations are high (> 0.095 ppmv), and the team may be a better predictor of ozone concentrations when concentrations are low (< 0.095 ppmv). The UAM-FM is also discussed in the context of other forecasting tools, primarily linear regression models and a no-skill, persistence-based technique.

Pollution Models May Need More Carbon

Urban air pollution models may not accurately reflect levels of volatile organic compounds (VOCs) in the atmosphere, a new research report suggests. VOCs play a role in the formation of ground-level ozone and secondary organic aerosols. Alastair C. Lewis of the University of Leeds, England, and his coworkers there and at Royal Melbourne Institute of Technology in Victoria, Australia, use gas chromatography to analyze urban air samples collected in Melbourne [ Nature , 405 , 778 (2000)]. The authors write that they can isolate more than 550 individual compounds using this method, which employs two chromatographic columns with different properties. Many compounds with more than six carbon atoms, the authors note, can only be isolated by using comprehensive chromatography. The peaks for many of these compounds are hidden in the baseline of conventional single-column chromatography analyses. If you start to look at the baseline in detail with this technique, you can see ...

News Briefs: Emissions from windshield washer fluid may contribute substantially to the formation of ground-level ozone in Canada,

News Briefs: Emissions from windshield washer fluid may contribute substantially to the formation of ground-level ozone in Canada,

CONGRESS EXAMINES VOC REGULATIONS

The availability of good scientific data and how the data are used by the Environmental Protection Agency were the subjects of a recent congressional hearing on the federal regulation of emissions from paints and coatings. But the underlying issue is concern among Republicans that EPA is regulating first and getting the data to support the regulations later. EPA is required by the 1990 Clean Air Act to study and then issue rules to reduce emissions of volatile organic compounds (VOCs) from consumer products that could contribute to formation of ground-level ozone. Ozone is considered a serious health problem by EPA. It is formed by the reaction of nitrogen oxides with various hydrocarbons in sunlight. EPA did a study of VOCs, released in March 1995, and concluded that VOCs from consumer products, particularly paints and coatings, contribute significantly to ozone formation. The report considered, in a broad way, the differences in the reactivities of various VOCs ...

Atmospheric Chemical Reactivity and Ozone-Forming Potentials of Potential CFC Replacements

The Montreal Protocol will lead to the eventual phase-out of the production of chlorofluorocarbons (CFCs) and other halogenated organic compounds that are implicated in the depletion of stratospheric ozone. Hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) have been developed as potential “in-kind” replacement compounds. To ensure that these compounds are acceptable, industry and regulatory agencies are assessing the safety, toxicology, and environmental impact of the HCFCs and HFCs before widespread production is commenced. One of the environmental issues concerns the contribution that the HCFCs and HFCs make to photochemical ozone production. Photochemical ozone creation potentials (POCPs) have been calculated using a photochemical trajectory model. The POCPs of the HCFCs and HFCs are low, indicating that these compounds do not have a large potential to contribute to ground-level ozone formation. This results from their low reactivity compared to the other, more reactive, organic compounds ...