Methane Volatile Organic Compounds Research Articles

The Islandwide Ambient Air Quality Monitoring Program in Sri Lanka

In recent decades, the combination of growth of major cities across the country, increased use of vehicles, rapid industrialization, and deficiencies in both planning and environmental regulations, has led to increasing the levels of air pollution and consequent health and environmental impacts. The observed levels of criteria air pollutants (CAPs) and hazardous air pollutants (HAPs) often reach magnitudes that are considered to be a threat to human health. Ambient concentrations of gaseous pollutants and fine particles are stable or even increasing over time. Being a responsible key organization in Sri Lanka, Central Environmental Authority has been engaged with an urban air quality monitoring program across the country since 2014 under financial sponsorship of the vehicle emission trust fund of the department of motor traffic. In this program, the criteria air pollutants such as PM2.5, PM10, SO2, NOx, CO, O3 and Non methane volatile organic compounds (NMVOCs) are monitored in major cities. The 24-hour continuous monitoring for seven days in each and every city are accomplished by using fully automated mobile ambient air quality monitoring station. As observed, the recorded average concentrations of each parameter, in major cities are maintained below the National ambient air quality standards. But it was found that there is a little increasing trend of PM2.5 and PM10 in major cities compared to other pollutants. It is also notable that the average concentrations of other parameters such as SO2, NO2, CO and O3 have been recorded below the National ambient air quality standards. However, these values are defined to 24-hour continuous monitoring for 07 days and it is an instant situation on ambient air quality in the cities considered. These pollutant concentrations have been given for 24-hour consecutive 07 days for a particular city and once a year monitoring for a particular season. Hence the data is very limited and not representative for the entire year. A large set of continuous monitoring data representing all seasons in Sri Lanka is also requires in order to introduce a standard methodology at the data processing. Further an improvement of current ambient air quality monitoring program is recommended in Sri Lanka taking into account the drawbacks identified. Keywords: Ambient air quality, Criteria air pollutants, Hazardous air pollutants, National ambient air quality standards

Tropospheric Ozone at Northern Mid-Latitudes: Modeled and Measured Long-Term Changes

In this paper, we investigate why current state-of-the-art chemistry-climate models underestimate the tropospheric ozone increase from the 1950s to the 1990s by approximately 50%. The accuracy of these models is vital, not only for understanding and predicting air quality globally, but also since they are used to quantify the contribution of ozone in the troposphere and lower stratosphere to climate change, where its greenhouse effect is largest. We briefly describe available northern mid-latitude ozone measurements, which include representative and reliable data from European sites that extend back to the 1950s. We use the SOCOLv3 (Solar Climate Ozone Links version 3) global chemistry-climate model to investigate the individual terms of the tropospheric ozone budget. These include: inflow from the stratosphere, dry deposition, and chemical formation and destruction. For 1960 to 2000 SOCOLv3 indicates a tropospheric ozone increase at 850 hPa over the Swiss Alps (Arosa) of 17 ppb, or around 30%. This increase is smaller than that seen in the surface ozone measurements but similar to other chemistry-climate models, including those with more complex NMVOC (Non Methane Volatile Organic Compound) schemes than SOCOLv3’s. It is likely that the underestimated increase in tropospheric ozone could be explained by issues in the underlying emissions inventories used in the model simulations, with ozone precursor emissions, particularly NOx (NO + NO2), from the 1960s being too large.

Urban eddy covariance measurements reveal significant missing NOx emissions in Central Europe

Nitrogen oxide (NOx) pollution is emerging as a primary environmental concern across Europe. While some large European metropolitan areas are already in breach of EU safety limits for NO2, this phenomenon does not seem to be only restricted to large industrialized areas anymore. Many smaller scale populated agglomerations including their surrounding rural areas are seeing frequent NO2 concentration violations. The question of a quantitative understanding of different NOx emission sources is therefore of immanent relevance for climate and air chemistry models as well as air pollution management and health. Here we report simultaneous eddy covariance flux measurements of NOx, CO2, CO and non methane volatile organic compound tracers in a city that might be considered representative for Central Europe and the greater Alpine region. Our data show that NOx fluxes are largely at variance with modelled emission projections, suggesting an appreciable underestimation of the traffic related atmospheric NOx input in Europe, comparable to the weekend-weekday effect, which locally changes ozone production rates by 40%.

Anthropogenic non-methane volatile hydrocarbons at Mt. Cimone (2165 m a.s.l., Italy): Impact of sources and transport on atmospheric composition

To advance our understanding of the factors that affect pollution in mountainous areas, long-term, high frequency measurements of thirteen Non Methane Volatile Organic Compounds (NMVOCs) have been carried out at the atmospheric observatory on the top of Mt. Cimone (2165 m a.s.l.), whose location is ideal for sampling both aged air masses representing the regional background and polluted air masses coming from nearby sources of anthropogenic pollution.An analysis of the NMVOC time series available at Mt. Cimone during 2010–2014 was used to examine the influence of transport processes on NMVOC atmospheric composition and to derive information on the emission sources. We performed a multifactor principal component analysis whose results allowed us to identify the source categories emitting the NMVOCs measured at Mt. Cimone as well as to assess transport ranges in winter and summer. Aged air masses, due to long-range transport and related to vehicular traffic exhaust emissions accounted for 78% of the NMVOC variability in winter and 62% in summer, whereas evaporative emissions, likely to be associated with fresh emissions from nearby sources, accounted for 12% of the NMVOC variability and 24% in winter and summer, respectively. Such results have been confirmed by a further analysis in which the NMVOC variability as a function of their atmospheric lifetimes has been evaluated. The ratios of alkane isomers potentially provides a metric to investigate seasonal changes in NMVOCs composition and in the emission fields of butanes and pentanes, suggesting that during the summer the butanes are originating mainly from the European domain and that for pentanes non-anthropogenic sources may be contributing to the measured concentrations.

Estimating the benefits of emissions reductions in complex atmospheres

Air pollution is a globally ubiquitous consequence of increasing reliance on fossil fuel–based industrial, residential, electrical, and transportation energy systems. Controlling emissions can be costly, and it is therefore useful to evaluate the benefits of reduced pollution. Estimation of the damages resulting from pollution and economic evaluation of the benefits of avoiding that damage is confounded by the nature of the chemical transformations emissions undergo in the atmosphere. This paper describes the mechanics of damage estimation and valuation, and then develops and presents some practical and theoretical limitations of such estimation. The focus is on changes in ambient tropospheric ozone resulting from the activity of nitrogen oxides and non–methane volatile organic compounds. The chemical model of ozone formation is related to the neoclassical economic production model to demonstrate difficulties for estimating the derived demand for reductions in nitrogen oxide emissions.

English

This study assessed variations of ambient volatile organic compounds and carbon monoxide (CO) levels in Blantyre City, Malawi. Volatile organic compounds and carbon monoxide measurement was done using the Multi-Gas Monitor between August and December, 2010. Rapid urbanization and lack of standard enforcement on air pollution as well as lack of data on pollutant levels in the city prompted this study. The study focused on methane volatile organic compounds and non-methane volatile compounds besides carbon monoxide. Results of the analysis showed that non-methane volatile compound levels were highest at public bus terminuses with 12.40 ± 0.83 ppm, and lowest for industrial locations (2.16 ± 0.09 ppm). However, all points registered zero (0.00) ppm for methane volatile organic compounds. Similarly, mean levels of carbon monoxide were highest at public bus terminuses with 10.92 ± 0.74 ppm, and lowest for industrial locations (1.11 ± 0.13 ppm). With the exception of Ginnery Corner, all the sampling points had levels of both parameters within the air quality standards. The study revealed a spatial and diurnal variation of the pollutants in all sampling points. It further revealed that the sources of these pollutants are diverse with vehicular emissions being the main source for Masauko Chipembere highway.   Key words: Air pollution, ambient, permissible limit, urban, vehicular emission

Deposition fluxes of terpenes over grassland

Eddy covariance flux measurements were carried out for two subsequent vegetation periods above a temperate mountain grassland in an alpine valley using a proton-transfer-reaction - mass spectrometer (PTR-MS) and a PTR-time of flight - mass spectrometer (PTR-TOF). In 2008 and during the first half of the vegetation period 2009 the volume mixing ratios (VMRs) for the sum of monoterpenes (MTs) were typically well below 1 ppbv and neither MT emission nor deposition was observed. After a hailstorm in July 2009 an order of magnitude higher amount of terpenes was transported to the site from nearby coniferous forests causing elevated VMRs. As a consequence, deposition fluxes of terpenes to the grassland, which continued over a time period of several weeks without significant re-emission, were observed. For days without precipitation the deposition occurred at velocities close to the aerodynamic limit. In addition to monoterpene uptake, deposition fluxes of the sum of sesquiterpenes (SQTs) and the sum of oxygenated terpenes (OTs) were detected. Considering an entire growing season for the grassland (i.e., 1st of April to 1st of November), the cumulative carbon deposition of monoterpenes reached 276 mg C m-2. This is comparable to the net carbon emission of methanol (329 mg C m-2), which is the dominant non methane volatile organic compound (VOC) emitted from this site, during the same time period. It is suggested that deposition of monoterpenes to terrestrial ecosystems could play a more significant role in the reactive carbon budget than previously assumed.

Ancillary benefits of climate policy in a small open economy: The case of Sweden

It is increasingly recognised that GHG reduction policies can have important ancillary benefits in the form of positive local and regional environmental impacts. The purpose of this paper is to estimate the domestic ancillary pollution benefits of climate policy in Sweden, and investigate how these are affected by different climate policy designs. The latter differ primarily in terms of how the country chooses to meet a specific target and where the necessary emission reductions take place. The analysis relies on simulations within the energy system optimisation model TIMES-Sweden, and focuses on four non-GHG pollutants: Nitrogen Oxides (NOX), Non Methane Volatile Organic Compounds (NMVOC), inhalable particles (PM2.5), and Sulphur dioxide (SO2). The simulations permit detailed assessments of the respective technology and fuel choices that underlie any net changes in the estimated ancillary effects. The results indicate that the ancillary benefits constitute a far from insignificant share of total system costs, and this share appears to be highest in the scenarios that entail the largest emission reductions domestically. This result reflects the fact that carbon dioxide emission reductions abroad also implies a lost opportunity of achieving substantial domestic welfare gain from the reductions of regional and local environmental pollutants.

The influence of emission changes on ozone concentrations and nitrogen deposition into the southern North Sea

The impact of changes in amount of emission for NO X (Nitrogen monoxide NO + Nitrogen dioxide NO 2 ) and NMVOC (Non Methane Volatile Organic Compounds) on concentrations of ozone (O 3 ), NO x , nitric acid (HNO 3 ) and on nitrogen deposition in the area of the southern North Sea are investigated. One reference case for the period 16 June till 20 June, 1998 and six emission scenarios are calculated. Spatial and temporal emission patterns are kept and overall emission factors are used that correspond to years 1998 (reference), 1970 and 2010. Some more artificial emission scenarios are constructed to investigate the effect of a changed ratio of NO x to NMVOC emissions. The meteorology is unchanged for all scenarios. The studies are performed with the meteorology/chemistry model M-SYS (METRAS/MECTM) including a simple aerosol chemistry and using a horizontal resolution of 8 km. Changes in emissions of NMVOC and NO x cause nonlinear changes in O 3 , NO x and HNO 3 concentrations. The concentration changes depend on emission changes and on changes in the ratio of NMVOC to NO X emissions. The whole area, over land and water, turns out to be in the NMVOC limited regime. Ozone scenario concentrations linearly depend on the ratio of NMVOC to NO x emissions. NO x concentrations linearly depend on changes in the total emissions of NO x and NMVOC. They are inversely related to changes in the ratio of NMVOC to NO x emissions. HNO 3 concentrations mainly depend on the total emission changes with NO x emission changes being of doubled relevance compared to NMVOC emission changes. The same relation is found for nitrogen deposition. Compared to mean ozone concentrations from the reference case, higher (lower) NO x emissions reduce (increase) ozone concentrations, while HNO 3 concentrations are increased (reduced). In contrast, reduced (increased) NMVOC emissions reduce (increase) both, ozone and HNO 3 concentrations and, in addition, the nitrogen deposition.

Regulations Concerning Agriculture and Air Pollution

The main issues related to the atmospheric pollution are the stratospheric ozone depletion, the transboundary air pollution, the troposphere air quality and the climate change. The three last decades have seen the birth of several measures for the atmosphere safeguard. Agricultural activities play a key role in determining, preventing and mitigating atmospheric pollution. The emission to atmosphere of different ozone-depleting substances is regulated by the Montreal Protocol. The role of agriculture activity in ozone depletion is linked to the utilization of methyl bromide as soil sterilant and to the emission of nitrogen oxides and nitrous oxide, from agricultural soils. The Convention on long-range transboundary air pollution regulates the emission of several pollutants, i.e. sulphur dioxide, nitrogen oxides, ammonia, non methane volatile organic compounds, carbon monoxide, heavy metals, persistent organic pollutants, and tropospheric ozone. The agriculture sector is responsible for a large part of the emissions of ammonia and nitrogen oxides, mainly through manure management and nitrogen fertilization, and of most persistent organic pollutants, largely used in the past as insecticides and fungicides. The increase of the greenhouse gases (GHGs) concentration in the atmosphere is under the control of the Kyoto Protocol. Agriculture accounts for 59-63% of global non-CO2 GHGs emissions but at the same time it contributes to the atmospheric CO2 concentration stabilisation through the substitution of fossil fuels by biofuels and the sequestration of C in soil and vegetal biomass. In this paper we provide an outline of the numerous scientific and legislative initiatives aimed at protecting the atmosphere, and we analyse in detail the agriculture sector in order to highlight both its contribution to atmospheric pollution and the actions aimed at preventing and mitigating it.

The impacts of CO2 capture on transboundary air pollution in the Netherlands

The focus of this research is to develop a first assessment of the impacts of the implementation of CO2 capture technologies in the Dutch power sector on the transboundary air pollution (SO2,NOX,NH3,NMV OC,PM10 and PM2.5) levels in 2020. Results show that for the power sector SO2 emissions will be very low for scenarios that include large scale implementation of Carbon Capture and Storage (CCS). The annual emissions of NOx are estimated to be lower in all scenarios with greenhouse gas reductions. However, applying the post-combustion technology on existing power plants may result in higher NOx emissions per kWh. Both SO2 and NOx emissions from the power sector are a substantial part of the current national total. Large scale implementation of the post-combustion CO2 capture technology may result in more than 5 times higher NH3 emissions compared to scenarios without CCS and to other capture options (i.e. pre-combustion and oxyfuel combustion). Particulate Matter (PM) emissions are lower in the scenarios with CO2 reduction. A scenario with large scale implementation of the oxyfuel technology shows the lowest emissions of PM. In the scenarios with post-combustion capture Non Methane Volatile Organic Compounds emissions may increase due to the emission of solvents used in the capture process. The main conclusion is that climate policy and air quality policy are entwined and may result in synergies and trade-offs. Quantification of these synergies and trade-offs however encompasses inaccuracies due to data uncertainty and knowledge gaps. © 2009 Elsevier Ltd. All rights reserved.

NMVOCs and CO Emission Inventory in East Asia

For analyzing acidification in East Asia, long range transportation models has been developed, which require emissions inventories of the precursors. SO2 and NOx emissions inventories were reported previously; here emissions of NMVOCs (Non methane volatile organic compounds) and CO in East Asia; China, Republic Korea, Japan and Taiwan area, are estimated. For the years 1994–95, the total emissions of NMVOC and CO in East Asia are estimated at 17.7 and 94.1Tg/y respectively. Small coal boiler and biomass use for residences are dominant sources of NMVOCs in the area, especially in China. More than half of CO emission comes from biomass use in residences in China. Regionally at east costal area in China high density emission is seen in the 1×1 degree grid emission map.