Secondary organic aerosol formation from &amp;lt;i&amp;gt;α&amp;lt;/i&amp;gt;-pinene, alkanes, and oil-sands-related precursors in a new oxidation flow reactor

Li, Kun; Liggio, John; Lee, Patrick; Han, Chong; Liu, Qifan; Li, Shao-Meng

doi:10.5194/acp-19-9715-2019

Cited by 42 publications

(90 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The H/C and O/C values of n-dodecane and β-caryophyllene SOA coating in Fig. 7 are smaller than that of toluene SOA, which are in agreement with previous studies (Li et al, 2019;Pereira et al, 2019;Simonen et al, 2017). The slopes of H/C and O/C values of these two types of SOA and their respective two precursors (Fig.…”

Section: Ice Nucleation On Bc Coated With Soa Materialssupporting

confidence: 91%

The effects of morphology, mobility size and SOA material coating on the ice nucleation activity of black carbon in the cirrus regime

Zhang¹,

Zhang²,

Wolf³

et al. 2020

Preprint

View full text Add to dashboard Cite

Abstract. There is evidence that black carbon (BC) particles may affect cirrus formation and hence global climate by acting as potential ice nucleating particles (INPs) in the troposphere. Nevertheless, the ice nucleation (IN) ability of bare BC and BC coated with secondary organic aerosol (SOA) material remains uncertain. We have systematically examined the IN ability of 100–400 nm size-selected BC particles with different morphologies and different SOA coatings representative of anthropogenic (toluene and n-dodecane) and biogenic (β-caryophyllene) sources in the cirrus regime (−46 to −38 °C). Several aerosolized BC proxies were selected to represent different particle morphologies and oxidation levels. Atmospheric aging was further replicated with exposure of SOA-coated BC to OH. The results demonstrate that the 400 nm hydrophobic BC types nucleate ice only at or near the homogeneous freezing threshold (−42 to −46 ˚C). Deposition IN, as opposed to purely homogeneous freezing, was observed to occur for some BC types between 100–200 nm within the investigated temperature range. More fractal BC particles did not consistently act as superior deposition INPs over more spherical ones. SOA coating generated by oxidizing β-caryophyllene with O3 did not seem to affect BC IN ability. However, SOA coatings generated from OH oxidation of various organic species did exhibit higher IN onset supersaturation ratio with respect to ice (SSi) compared with bare BC particles, with toluene SOA coating showing an increase of SSi by 0.1–0.15 while still below the homogeneous threshold. n-dodecane and β-caryophyllene-derived SOA only froze in the homogeneous regime. We attribute the inhibition of IN ability to the filling of the pores on the BC surface by the SOA material coating. OH exposure levels of all SOA coating experiments, from an equivalent atmospheric 10 days to 90 days, did not render significant differences in IN potential. Our study suggests that BC particles with large sizes and/or oxidized surfaces generally exhibit better IN ability, and that the organic coating materials can inhibit ice formation.

show abstract

Section: Ice Nucleation On Bc Coated With Soa Materialssupporting

confidence: 91%

The effects of morphology, mobility size and SOA material coating on the ice nucleation activity of black carbon in the cirrus regime

Zhang¹,

Zhang²,

Wolf³

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…The mixing ratios of m-xylene and α-pinene introduced into the PFA OFR were in the ranges of 20-118 and 13-145 ppb, respectively. The OH exp was not measured simultaneously during the yield experiments, but applying the OFR254 OH exposure estimation equation as a function of O 3 , RH, and UV lamp power (Peng et al, 2015) and the assumption that the OH reactivity was the same for both sets of measurements resulted in estimated values that are consistent with the measured OHexp described in Sect. 3.1.…”

Section: Soa Yield Measurementsmentioning

confidence: 81%

“…The PFA OFR is an OFR254-type oxidation flow reactor, in which O 3 must be generated externally and introduced with the sample flow (Li et al, 2015). Among the advantages of OFR185-type oxidation flow reactors is their ability to be operated without an inlet, which is often desirable for field investigations.…”

Section: Methodsmentioning

confidence: 99%

“…In addition to increasing the average UV intensity, the use of the reflective gasket reduced the gradient in intensity, resulting in more uniform OH generation throughout the reactor. The maximum photon flux (with the maximum lamp power) was estimated for ozone concentration measured at the exit of the OFR and known RH using a photochemical model used in previous studies (Li et al, 2015;Peng et al, 2015Peng et al, , 2019. The input photon flux of the model was adjusted to match the measured ozone concentration and OH exposure, which resulted in a maximum photon flux estimate of ∼ 2.4 × 10 14 photons cm −2 s −1 and 1.1 × 10 15 without and with the ePTFE layer, resulting in about 1.5 and 7 times, respectively, that calculated from the lamp output power when neglecting any reflection.…”

Section: Uv Intensity Distribution and Oh Exp Levelmentioning

confidence: 99%

“…With most OFRs, the lamps are either mounted on the inner surface for metal-wall reactors or outside for quartz-based reactors. The emitted wavelengths and intensity uniformity of the UV lamp(s) are also important considerations in reactor design (Li et al, 2015). Selection of wall materials and any surface treatments is guided by an application-dependent balance of the importance of loss of gas-phase compounds or delays in their transfer, loss of charged particles to non-conductive materials, and UV transmittance for designs for which the lamps are outside of the reactor.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Design and characterization of a new oxidation flow reactor for laboratory and long-term ambient studies

Collins

2021

Atmos. Meas. Tech.

View full text Add to dashboard Cite

Abstract. Oxidation flow reactors (OFRs) are frequently used to study the formation and evolution of secondary aerosol (SA) in the atmosphere and have become valuable tools for improving the accuracy of model simulations and for depicting and accelerating realistic atmospheric chemistry. Driven by rapid development of OFR techniques and the increasing appreciation of their wide application, we designed a new all-Teflon reactor, the Particle Formation Accelerator (PFA) OFR, and characterized it in the laboratory and with ambient air. A series of simulations and experiments were performed to characterize (1) flow profiles in the reactor using computational fluid dynamics (CFD) simulations, (2) the UV intensity distribution in the reactor and the influence of it and varying O3 concentration and relative humidity (RH) on the resulting equivalent OH exposure (OHexp), (3) transmission efficiencies for gases and particles, (4) residence time distributions (RTDs) for gases and particles using both computational simulations and experimental verification, (5) the production yield of secondary organic aerosol (SOA) from oxidation of α-pinene and m-xylene, (6) the effect of seed particles on resulting SA concentration, and (7) SA production from ambient air in Riverside, CA, US. The reactor response and characteristics are compared with those of a smog chamber (Caltech) and of other oxidation flow reactors: the Toronto Photo-Oxidation Tube (TPOT), the Caltech Photooxidation Flow Tube (CPOT), the TUT Secondary Aerosol Reactor (TSAR), quartz and aluminum versions of Potential Aerosol Mass reactors (PAMs), and the Environment and Climate Change Canada OFR (ECCC-OFR). Our studies show that (1) OHexp can be varied over a range comparable to that of other OFRs; (2) particle transmission efficiency is over 75 % in the size range from 50 to 200 nm, after minimizing static charge on the Teflon surfaces; (3) the penetration efficiencies of CO2 and SO2 are 0.90 ± 0.02 and 0.76 ± 0.04, respectively, the latter of which is comparable to estimates for LVOCs; (4) a near-laminar flow profile is expected based on CFD simulations and suggested by the RTD experiment results; (5) m-xylene SOA and α-pinene SOA yields were 0.22 and 0.37, respectively, at about 3 × 1011 molec. cm−3 s OH exposure; (6) the mass ratio of seed particles to precursor gas has a significant effect on the amount of SOA formed; and (7) during measurements of SA production when sampling ambient air in Riverside, the mass concentration of SA formed in the reactor was an average of 1.8 times that of the ambient aerosol at the same time.

show abstract

A decadal synthesis of atmospheric emissions, ambient air quality, and deposition in the oil sands region

Horb

Wentworth

Makar

et al. 2021

Integr Envir Assess & Manag

Self Cite

View full text Add to dashboard Cite

This review is part of a series synthesizing peer‐reviewed literature from the past decade on environmental monitoring in the oil sands region (OSR) of northeastern Alberta. It focuses on atmospheric emissions, air quality, and deposition in and downwind of the OSR. Most published monitoring and research activities were concentrated in the surface‐mineable region in the Athabasca OSR. Substantial progress has been made in understanding oil sands (OS)‐related emission sources using multiple approaches: airborne measurements, satellite measurements, source emission testing, deterministic modeling, and source apportionment modeling. These approaches generally yield consistent results, indicating OS‐related sources are regional contributors to nearly all air pollutants. Most pollutants exhibit enhanced air concentrations within ~20 km of surface‐mining activities, with some enhanced >100 km downwind. Some pollutants (e.g., sulfur dioxide, nitrogen oxides) undergo transformations as they are transported through the atmosphere. Deposition rates of OS‐related substances primarily emitted as fugitive dust are enhanced within ~30 km of surface‐mining activities, whereas gaseous and fine particulate emissions have a more diffuse deposition enhancement pattern extending hundreds of kilometers downwind. In general, air quality guidelines are not exceeded, although these single‐pollutant thresholds are not comprehensive indicators of air quality. Odor events have occurred in communities near OS industrial activities, although it can be difficult to attribute events to specific pollutants or sources. Nitrogen, sulfur, polycyclic aromatic compounds (PACs), and base cations from OS sources occur in the environment, but explicit and deleterious responses of organisms to these pollutants are not as apparent across all study environments; details of biological monitoring are discussed further in other papers in this special series. However, modeling of critical load exceedances suggests that, at continued emission levels, ecological change may occur in future. Knowledge gaps and recommendations for future work to address these gaps are also presented. Integr Environ Assess Manag 2022;18:333–360. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

show abstract

Secondary organic aerosol formation from <i>α</i>-pinene, alkanes, and oil-sands-related precursors in a new oxidation flow reactor

Cited by 42 publications

References 61 publications

The effects of morphology, mobility size and SOA material coating on the ice nucleation activity of black carbon in the cirrus regime

The effects of morphology, mobility size and SOA material coating on the ice nucleation activity of black carbon in the cirrus regime

Design and characterization of a new oxidation flow reactor for laboratory and long-term ambient studies

A decadal synthesis of atmospheric emissions, ambient air quality, and deposition in the oil sands region

Contact Info

Product

Resources

About