Impact of SOx, NOx and NH3 emission reductions on PM2.5 concentrations across Europe: Hints for future measure development

Abstract. Air pollution is one of the main causes of damages to human health in Europe with an estimate of about 380 000 premature deaths per year in the EU28, as the result of exposure to fine particulate matter (PM2.5) only. In this work, we focus on one specific region in Europe, the Po basin, a region where chemical regimes are the most complex, showing important non-linear processes, especially those related to interactions between NOx and NH3. We analyse the sensitivities of PM2.5 to NOx and NH3 emissions by means of a set of EMEP simulations performed with different levels of emission reductions, from 25 % up to a total switch-off of those emissions. Both single and combined precursor reduction scenarios are applied to determine the most efficient emission reduction strategies and quantify the interactions between NOx and NH3 emission reductions. The results confirmed the peculiarity of secondary PM2.5 formation in the Po basin, characterised by contrasting chemical regimes within distances of few (hundreds of) kilometres, as well as strong non-linear responses to emission reductions during wintertime. One of the striking results is the increase of the PM2.5 concentration levels when NOx emission reductions are applied in NOx-rich areas, such as the surroundings of Bergamo. The increased oxidative capacity of the atmosphere is the cause of the increase of PM2.5 induced by a reduction in NOx emission. This process can have contributed to the absence of significant PM2.5 concentration decrease during the COVID-19 lockdowns in many European cities. It is important to account for this process when designing air quality plans, since it could well lead to transitionary increases in PM2.5 at some locations in winter as NOx emission reduction measures are gradually implemented. While PM2.5 responses to NOx and NH3 emission reduction show large variations seasonally and spatially, these responses remain close to linear, i.e. proportional to the emission reduction levels, at least up to −50 % because secondary aerosol formation chemical regimes are not modified by those relatively moderate ranges.

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Non-linear response of PM2.5 to changes in NOx and NH3 emissions in the Po basin (Italy): consequences for air quality plans

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-9309-2021 ◽

2021 ◽

Vol 21 (12) ◽

pp. 9309-9327

Author(s):

Philippe Thunis ◽

Alain Clappier ◽

Matthias Beekmann ◽

Jean Philippe Putaud ◽

Cornelis Cuvelier ◽

...

Keyword(s):

Air Quality ◽

Emission Reduction ◽

Fine Particulate Matter ◽

Oxidative Capacity ◽

Nox Emission ◽

Linear Processes ◽

Emission Reductions ◽

Nh3 Emission ◽

Non Linear ◽

Pm2.5 Concentration

Abstract. Air pollution is one of the main causes of damages to human health in Europe, with an estimate of about 380 000 premature deaths per year in the EU28, as the result of exposure to fine particulate matter (PM2.5) only. In this work, we focus on one specific region in Europe, the Po basin, a region where chemical regimes are the most complex, showing important non-linear processes, especially those related to interactions between NOx and NH3. We analyse the sensitivity of PM2.5 concentration to NOx and NH3 emissions by means of a set of EMEP model simulations performed with different levels of emission reductions, from 25 % up to a total switch-off of those emissions. Both single and combined precursor reduction scenarios are applied to determine the most efficient emission reduction strategies and quantify the interactions between NOx and NH3 emission reductions. The results confirmed the peculiarity of secondary PM2.5 formation in the Po basin, characterised by contrasting chemical regimes within distances of a few (hundred) kilometres, as well as non-linear responses to emission reductions during wintertime. One of the striking results is the slight increase in the PM2.5 concentration levels when NOx emission reductions are applied in NOx-rich areas, such as the surroundings of Bergamo. The increased oxidative capacity of the atmosphere is the cause of the increase in PM2.5 induced by a reduction in NOx emission. This process could have contributed to the absence of a significant PM2.5 concentration decrease during the COVID-19 lockdowns in many European cities. It is important to account for this process when designing air quality plans, since it could well lead to transitionary increases in PM2.5 at some locations in winter as NOx emission reduction measures are gradually implemented. While PM2.5 chemical regimes, determined by the relative importance of the NOx vs. NH3 responses to emission reductions, show large variations seasonally and spatially, they are not very sensitive to moderate (up to 50 %–60 %) emission reductions. Beyond 25 % emission reduction strength, responses of PM2.5 concentrations to NOx emission reductions become non-linear in certain areas of the Po basin mainly during wintertime.

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Predicting the Nonlinear Response of PM2.5 and Ozone to Precursor Emission Changes with a Response Surface Model

Atmosphere ◽

10.3390/atmos12081044 ◽

2021 ◽

Vol 12 (8) ◽

pp. 1044

Author(s):

James T. Kelly ◽

Carey Jang ◽

Yun Zhu ◽

Shicheng Long ◽

Jia Xing ◽

...

Keyword(s):

Air Quality ◽

Response Surface ◽

Nonlinear Response ◽

Response Surface Model ◽

Surface Model ◽

Emission Reductions ◽

Ozone Concentrations ◽

Nh3 Emission ◽

Out Of Sample ◽

Emission Changes

Reducing PM2.5 and ozone concentrations is important to protect human health and the environment. Chemical transport models, such as the Community Multiscale Air Quality (CMAQ) model, are valuable tools for exploring policy options for improving air quality but are computationally expensive. Here, we statistically fit an efficient polynomial function in a response surface model (pf-RSM) to CMAQ simulations over the eastern U.S. for January and July 2016. The pf-RSM predictions were evaluated using out-of-sample CMAQ simulations and used to examine the nonlinear response of air quality to emission changes. Predictions of the pf-RSM are in good agreement with the out-of-sample CMAQ simulations, with some exceptions for cases with anthropogenic emission reductions approaching 100%. NOx emission reductions were more effective for reducing PM2.5 and ozone concentrations than SO2, NH3, or traditional VOC emission reductions. NH3 emission reductions effectively reduced nitrate concentrations in January but increased secondary organic aerosol (SOA) concentrations in July. More work is needed on SOA formation under conditions of low NH3 emissions to verify the responses of SOA to NH3 emission changes predicted here. Overall, the pf-RSM performs well in the eastern U.S., but next-generation RSMs based on deep learning may be needed to meet the computational requirements of typical regulatory applications.

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Work Interruptions: Measure Development and Testing

PsycEXTRA Dataset ◽

10.1037/e518362013-533 ◽

2011 ◽

Author(s):

Jeff Muldoon ◽

Russell A. Matthews

Keyword(s):

Measure Development ◽

Work Interruptions

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Normalization Measure Development Questionnaire--Dutch Version

PsycTESTS Dataset ◽

10.1037/t76657-000 ◽

2019 ◽

Author(s):

Christiaan Vis ◽

Jeroen Ruwaard ◽

Tracy Finch ◽

Tim Rapley ◽

Derek de Beurs ◽

...

Keyword(s):

Measure Development ◽

Dutch Version

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Normalization Measure Development Questionnaire

PsycTESTS Dataset ◽

10.1037/t76771-000 ◽

2013 ◽

Author(s):

Tracy L. Finch ◽

Tim Rapley ◽

Melissa Girling ◽

Frances S. Mair ◽

Elizabeth Murray ◽

...

Keyword(s):

Measure Development

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Quantifying the Greenhouse Gas Emission Reductions Associated with Recycling Hot Mix Asphalt

Road Materials and Pavement Design ◽

10.3166/rmpd.12.57-77 ◽

2011 ◽

Vol 12 (1) ◽

pp. 57-77

Author(s):

James W Lewis ◽

Morton A Barlaz ◽

Akhtar Tayebali ◽

S Ranji Ranjithan

Keyword(s):

Greenhouse Gas ◽

Hot Mix Asphalt ◽

Greenhouse Gas Emission ◽

Gas Emission ◽

Emission Reductions

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Reduce odor and NH3 emission: condensation of the carbonatation vapors

Sugar Industry ◽

10.36961/si18736 ◽

2017 ◽

pp. 534-537

Author(s):

Nico Antens ◽

Jan L.M. Struijs

Keyword(s):

Direct Contact ◽

Waste Heat ◽

Pilot Scale ◽

Sugar Production ◽

Two Stage ◽

Indirect Contact ◽

Nh3 Emission ◽

Emission Limits ◽

Plant Trials ◽

Contact Condensation

At beet sugar production, vapors from first and second carbonatation contain a significant amount of odor components, NH3 and waste heat, which are normally directly released into the environment. Due to sustainability motivations, obligations regarding odor nuisance and expected stricter regulations regarding NH3 emission limits, Suiker Unie decided to take measures to reduce emission via the carbonatation vapors. During the 2015 beet campaign, pilot scale plant trials have been performed to investigate the effectiveness of indirect contact and direct contact condensation of these vapors. Based on this experimental work a two-stage gas scrubbing concept was designed: in the first stage main goal is condensing the vapors and reuse the heat of condensation to heat up limed juice, while the actual scrubbing takes place in the second scrubber. This two-stage gas scrubbing installation has been built at the Vierverlaten factory and was started up in the 2016 beet campaign. The background, pilot scale trials, concept of design and achieved reductions in odor and NH3 emission at industrial scale are discussed.

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