Fine particle characterization in a coastal city in China: composition, sources, and impacts of industrial emissions

Abstract

<p><strong>Abstract.</strong> Aerosol composition and sources have been extensively studied in developed regions in China, however, aerosol chemistry in coastal regions of eastern China with high industrial emissions remains poorly characterized. Here we have a comprehensive characterization of aerosol composition and sources near two large steel plants in a coastal city in Shandong in fall and spring seasons using a PM<sub>2.5</sub> Time-of-Flight Aerosol Chemical Speciation Monitor. The average (±1σ) mass concentration of PM<sub>2.5</sub> in spring 2019 (54 ± 44 μg/m<sup>3</sup>) was approximately twice that (26 ± 23 μg/m<sup>3</sup>) in fall 2018. Aerosol composition was substantially different between the two seasons. While organics accounted for ∼30 % of the total PM<sub>2.5</sub> mass in both seasons, sulfate showed a considerable decrease from 28 % in September to 16 % in March, which was associated with a large increase in nitrate contribution from 17 % to 32 %. Positive matrix factorization analysis showed that secondary organic aerosol (SOA) dominated the total OA in both seasons on average accounting for 92 % and 86 %, respectively, while the contributions of traffic-related hydrocarbon-like OA were comparable (8–9 %). During this study, we observed significant impacts of steel plants emissions on aerosol chemistry nearby. The results showed that aerosol particles emitted from the steel plants were overwhelmingly dominated by ammonium sulfate/ammonium bisulfate with the peak concentration reaching as high as 224 μg/m<sup>3</sup>. Further analysis showed similar mass ratios of NO<sub>x</sub>/CO (13.7) and NO<sub>x</sub>/SO<sub>2</sub> (1.24) from the two different steel plants, which were largely different from those during periods in the absence of industrial plumes. Bivariate polar plot analysis also supported the dominant source region of ammonium sulfate, CO and SO<sub>2</sub> from the southwest steel plants. Our results might have significant implications for better quantification of industrial emissions using ammonium sulfate and the ratios of gaseous species as tracers in the future.</p>

Direct Observation of Sulfate Explosive Growth in Wet Plumes Emitted From Typical Coal‐Fired Stationary Sources

“…Referring to the rate calculation equations summarized in Table , the S (IV) oxidation rates in the stack plumes under the two pathways in the CFPPs, industrial boilers, and steel sintering plants are listed in Table . The calculated total production rate at pH <3 ranged from 0.02 to 0.39 mg/m 3 /s with a mean value of 0.11 mg/m 3 /s in the stack plumes, which is 10 4 ∼10 5 times higher than that estimated during the Chinese haze events with ∼10 μg/m 3 /h level (Dallosto & Harrison, 2006; Lei et al., 2020). The production rate of the steel sintering sector is much higher than that of the other two sectors, because the flue gases from sintering plants contain a high TMI contents (Fe 3+ and Mn 2+ ), whose pathway contributes the most (∼99.5%) to the total SO 4 2− production rate (0.39 mg/m 3 /s).…”

Real‐time characterization of aerosol particle composition, sources and influences of increased ventilation and humidity in an office

“…The office accommodates eight work stations and has three windows facing outdoors and two doors facing the hallway. An Aerodyne Time‐of‐Flight Aerosol Chemical Speciation Monitor (ToF‐ACSM) equipped with a PM 2.5 aerodynamic lens and a capture vaporizer (CV), which provides quantitative characterization of the non‐refractory chemical constituents of fine particles (NR‐PM 2.5 ), 33 and an aethalometer (AE33, Magee Scientific) measuring BC were deployed in the office. Temperature ( T ) and relative humidity (RH) in the office were monitored using a RH& T probe (Vaisala HMP155).…”

“…Calibrations were performed before and during the field sampling period using ammonium nitrate and ammonium sulfate. Detailed data analysis procedures of ToF‐ACSM data can be found in Lei et al 33 The bilinear model PMF analysis was performed on the organic mass spectra from both indoor and outdoor ToF‐ACSM measurements separately to determine the potential sources and processes of different OA factors. Note that PMF was performed to different chunks of data from unperturbed measurement, “open‐close windows” experiments on polluted and clean days and “dampness” experiment separately.…”