Supplementary material to "Understanding the Primary Emissions and Secondary Formation of Gaseous Organic Acids in the Oil Sands Region of Alberta, Canada"

Abstract. Organic acids are known to be emitted from combustion processes and are key photochemical products of biogenic and anthropogenic precursors. Despite their multiple environmental impacts, such as on acid deposition and human–ecosystem health, little is known regarding their emission magnitudes or detailed chemical formation mechanisms. In the current work, airborne measurements of 18 gas-phase low-molecular-weight organic acids were made in the summer of 2013 over the oil sands region of Alberta, Canada, an area of intense unconventional oil extraction. The data from these measurements were used in conjunction with emission retrieval algorithms to derive the total and speciated primary organic acid emission rates, as well as secondary formation rates downwind of oil sands operations. The results of the analysis indicate that approximately 12 t day−1 of low-molecular-weight organic acids, dominated by C1–C5 acids, were emitted directly from off-road diesel vehicles within open pit mines. Although there are no specific reporting requirements for primary organic acids, the measured emissions were similar in magnitude to primary oxygenated hydrocarbon emissions, for which there are reporting thresholds, measured previously ( ≈  20 t day−1). Conversely, photochemical production of gaseous organic acids significantly exceeded the primary sources, with formation rates of up to ≈  184 t day−1 downwind of the oil sands facilities. The formation and evolution of organic acids from a Lagrangian flight were modelled with a box model, incorporating a detailed hydrocarbon reaction mechanism extracted from the Master Chemical Mechanism (v3.3). Despite evidence of significant secondary organic acid formation, the explicit chemical box model largely underestimated their formation in the oil sands plumes, accounting for 39, 46, 26, and 23 % of the measured formic, acetic, acrylic, and propionic acids respectively and with little contributions from biogenic VOC precursors. The model results, together with an examination of the carbon mass balance between the organic acids formed and the primary VOCs emitted from oil sands operations, suggest the existence of significant missing secondary sources and precursor emissions related to oil sands and/or an incomplete mechanistic and quantitative understanding of how they are processed in the atmosphere.

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Supplementary material to "Primary emissions versus secondary formation of fine particulate matter in the top polluted city, Shijiazhuang, in North China"

10.5194/acp-2018-760-supplement ◽

2018 ◽

Cited By ~ 1

Author(s):

Ru-Jin Huang ◽

Yichen Wang ◽

Junji Cao ◽

Chunshui Lin ◽

Jing Duan ◽

...

Keyword(s):

Particulate Matter ◽

North China ◽

Fine Particulate Matter ◽

Fine Particulate ◽

Secondary Formation ◽

Supplementary Material ◽

Primary Emissions

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Understanding the Primary Emissions and Secondary Formation of Gaseous Organic Acids in the Oil Sands Region of Alberta, Canada

10.5194/acp-2017-220 ◽

2017 ◽

Author(s):

John Liggio ◽

Samar G. Moussa ◽

Jeremy Wentzell ◽

Andrea Darlington ◽

Peter Liu ◽

...

Keyword(s):

Molecular Weight ◽

Organic Acids ◽

Organic Acid ◽

Oil Sands ◽

Box Model ◽

Chemical Mechanism ◽

Formation Mechanisms ◽

Low Molecular Weight ◽

Airborne Measurements ◽

Secondary Formation

Abstract. Organic acids are known to be emitted from combustion processes and are key photochemical products of biogenic and anthropogenic precursors. Despite their multiple environmental impacts, such as on acid deposition and human/ecosystem health, little is known regarding their emission magnitudes or detailed chemical formation mechanisms. In the current work, airborne measurements of 18 gas-phase low molecular weight organic acids were made in the summer of 2013 over the oil sands region of Alberta, Canada, an area of intense unconventional oil extraction. The data from these measurements were used in conjunction with emission retrieval algorithms to derive the total and speciated primary organic acid emission rates, as well as secondary formation rates downwind of oil sands operations. The results of the analysis indicate that approximately 12 tonnes day−1 of low molecular weight organic acids, dominated by C1–C5 acids, were emitted directly from off-road diesel vehicles within open pit mines. Although there are no specific reporting requirements for primary organic acids, the measured emissions were similar in magnitude to primary oxygenated hydrocarbon emissions measured previously (≈ 20 tonnes day−1), for which there are reporting thresholds. Conversely, photochemical production of gaseous organic acids significantly exceeded the primary sources, with formation rates up to ≈ 184 tonnes day−1 downwind of the oil sands facilities. The formation and evolution of organic acids from a Lagrangian flight were modeled with a box model, incorporating a detailed hydrocarbon reaction mechanism extracted from the Master Chemical Mechanism (v 3.3). Despite evidence of significant secondary organic acid formation, the explicit chemical box model largely underestimated their formation in the oil sands plumes, accounting for 39 %, 46 %, 26 % and 23 % of the measured formic, acetic, acrylic and propionic acids respectively, and with little contributions from biogenic VOC precursors. The model results, together with an examination of the carbon mass balance between the organic acids formed and the primary VOCs emitted from oils sands operations, suggest the existence of significant missing oil sands related secondary sources/precursor emissions and/or an incomplete mechanistic and quantitative understanding of how they are processed in the atmosphere.

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Supplementary material to "Sources and formation of carbonaceous aerosols in Xi'an, China: primary emissions and secondary formation constrained by radiocarbon"

10.5194/acp-2019-437-supplement ◽

2019 ◽

Author(s):

Haiyan Ni ◽

Ru-Jin Huang ◽

Junji Cao ◽

Jie Guo ◽

Haoyue Deng ◽

...

Keyword(s):

Carbonaceous Aerosols ◽

Secondary Formation ◽

Supplementary Material ◽

Primary Emissions

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Supplementary material to "Quantifying fugitive gas emissions from an oil sands tailings pond with open-path FTIR measurements"

10.5194/amt-2020-257-supplement ◽

2020 ◽

Author(s):

Yuan You ◽

Samar G. Moussa ◽

Lucas Zhang ◽

Long Fu ◽

James Beck ◽

...

Keyword(s):

Oil Sands ◽

Gas Emissions ◽

Tailings Pond ◽

Open Path ◽

Supplementary Material ◽

Oil Sands Tailings

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Primary emissions versus secondary formation of fine particulate matter in the most polluted city (Shijiazhuang) in North China

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-2283-2019 ◽

2019 ◽

Vol 19 (4) ◽

pp. 2283-2298 ◽

Cited By ~ 20

Author(s):

Ru-Jin Huang ◽

Yichen Wang ◽

Junji Cao ◽

Chunshui Lin ◽

Jing Duan ◽

...

Keyword(s):

Particulate Matter ◽

North China ◽

Fine Particulate Matter ◽

Mass Range ◽

Organic Aerosol ◽

Average Mass ◽

Episodic Events ◽

Secondary Formation ◽

Primary Emissions ◽

Pollution Events

Abstract. Particulate matter (PM) pollution is a severe environmental problem in the Beijing–Tianjin–Hebei (BTH) region in North China. PM studies have been conducted extensively in Beijing, but the chemical composition, sources, and atmospheric processes of PM are still relatively less known in nearby Tianjin and Hebei. In this study, fine PM in urban Shijiazhuang (the capital of Hebei Province) was characterized using an Aerodyne quadrupole aerosol chemical speciation monitor (Q-ACSM) from 11 January to 18 February in 2014. The average mass concentration of non-refractory submicron PM (diameter <1 µm, NR-PM1) was 178±101 µg m−3, and it was composed of 50 % organic aerosol (OA), 21 % sulfate, 12 % nitrate, 11 % ammonium, and 6 % chloride. Using the multilinear engine (ME-2) receptor model, five OA sources were identified and quantified, including hydrocarbon-like OA from vehicle emissions (HOA, 13 %), cooking OA (COA, 16 %), biomass burning OA (BBOA, 17 %), coal combustion OA (CCOA, 27 %), and oxygenated OA (OOA, 27 %). We found that secondary formation contributed substantially to PM in episodic events, whereas primary emissions were dominant (most significant) on average. The episodic events with the highest NR-PM1 mass range of 300–360 µg m−3 were comprised of 55 % of secondary species. On the contrary, a campaign-average low OOA fraction (27 %) in OA indicated the importance of primary emissions, and a low sulfur oxidation degree (FSO4) of 0.18 even at RH >90 % hinted at insufficient oxidation. These results suggested that in Shijiazhuang in wintertime fine PM was mostly from primary emissions without sufficient atmospheric aging, indicating opportunities for air quality improvement by mitigating direct emissions. In addition, secondary inorganic and organic (OOA) species dominated in pollution events with high-RH conditions, most likely due to enhanced aqueous-phase chemistry, whereas primary organic aerosol (POA) dominated in pollution events with low-RH and stagnant conditions. These results also highlighted the importance of meteorological conditions for PM pollution in this highly polluted city in North China.

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