scholarly journals Measurement on PM and its chemical compositions for real-world emissions from non-road and on-road diesel vehicles

2016 ◽  
Author(s):  
Min Cui ◽  
Yingjun Chen ◽  
Cheng Li ◽  
Junyu Zheng ◽  
Chongguo Tian ◽  
...  
Keyword(s):  
Real World ◽  
Water Soluble ◽  
Chemical Compositions ◽  
Fuel Quality ◽  
Operating Modes ◽  
Diesel Vehicles ◽  
Emission Standards ◽  
Soluble Ions ◽  
Wide Range ◽  
Polycyclic Aromatic

Abstract. With increasing population of both non-road and on-road diesel vehicles, the adverse effects of PM and its compositions (such as elemental carbon (EC), polycyclic aromatic hydrocarbons (PAHs)) on air quality and human health get more and more attention. However, characteristics of PM and its compositions emitted from diesel vehicles, particularly measured under real-world condition, are scarce. In this study, six excavators and five trucks, involving wide-range emission standards and working in different operating modes, were tested to characterize constituents of PM (including organic carbon (OC), EC, water soluble ions (WSIs), elements, and organic species such as PAHs, n-alkanes, hopanes and steranes). The average emission factors of PM (EFPM) for excavators and trucks were 829 ± 806 and 498 ± 234 mg kg−1 fuel, respectively, which are comparable with other studies. However, EFPM was significantly affected by fuel quality, operating modes and emission standards. High correlation (R2 = 0.79, p 

scholarly journals Measurement of PM and its chemical composition in real-world emissions from non-road and on-road diesel vehicles

2017 ◽  
Vol 17 (11) ◽  
pp. 6779-6795 ◽  
Author(s):  
Min Cui ◽  
Yingjun Chen ◽  
Yanli Feng ◽  
Cheng Li ◽  
Junyu Zheng ◽  
...  
Keyword(s):  
Real World ◽  
Measurement Data ◽  
Water Soluble ◽  
Fuel Quality ◽  
Operational Mode ◽  
Diesel Vehicles ◽  
Emission Standards ◽  
Operation Modes ◽  
Wide Range ◽  
Stage 1

Abstract. With the rapid growth in the number of both non-road and on-road diesel vehicles, the adverse effects of particulate matter (PM) and its constituents on air quality and human health have attracted increasing attentions. However, studies on the characteristics of PM and its composition emitted from diesel vehicles are still scarce, especially under real-world driving conditions. In this study, six excavators and five trucks that provided a wide range of emission standards and operation modes were tested, and PM emissions and their constituents – including organic carbon (OC), elemental carbon (EC), water-soluble ions (WSIs), elements, and organic species like polycyclic aromatic hydrocarbons (PAHs), n-alkanes, and hopanes – as well as steranes were analyzed and characterized. The average emission factors for PM (EFPM) from excavator and truck emissions were 829 ± 806 and 498 ± 234 mg kg−1 fuel, respectively. EFPM and PM constituents were significantly affected by fuel quality, operational mode, and emission standards. A significant correlation (R2 = 0. 79, p < 0. 01) was found between EFPM for excavators and the sulfur contents in fuel. The highest average EFPM for working excavators was 904 ± 979 mg kg−1 fuel as a higher engine load required in this mode. From pre-stage 1 to stage 2, the average EFPM for excavators decreased by 58 %. For trucks, the average non-highway EFPM at 548 ± 311 mg kg−1 fuel was higher than the highway EFPM at 497 ± 231 mg kg−1 fuel. Moreover, the reduction rates were 63.5 and 65.6 % when switched from China II and III to China IV standards, respectively. Generally, the PM composition emitted from excavators was dominated by OC (39. 2 ± 21. 0 %) and EC (33. 3 ± 25. 9 %); PM from trucks was dominated by EC (26. 9 ± 20. 8 %), OC (9. 89 ± 12 %), and WSIs (4. 67 ± 5. 74 %). The average OC ∕ EC ratios for idling and working excavators were 3 to 4 times higher than those for moving excavators. Although the EFPM for excavators and trucks was reduced with the constraint of regulations, the element fractions for excavators increased from 0.49 % in pre-stage 1 to 3.03 % in stage 2, and the fraction of WSIs for the China IV truck was 5 times higher than the average value of all other-level trucks. Furthermore, as compared with other diesel vehicles, wide ranges were found for excavators of the ratios of benzo[a]anthracene ∕ (benzo[a]anthracene + chrysene) (0.26–0.86), indeno[1,2,3-cd]pyrene ∕ (indeno[1,2,3-cd]pyrene + benzo[ghi]perylene) (0.20–1.0), and fluoranthene ∕ (fluoranthene + pyrene) (0.24–0.87), which might be a result of the complex characteristics of the excavator operation modes. A comparison of our results with those in the literature revealed that on-board measurement data more accurately reflect actual conditions. Although the fractions of the 16 priority PAHs in PM from the excavator and truck emissions were similar, the equivalent concentrations of total benzo[a]pyrene of excavators were 31 times than that for trucks, implying that more attention should be paid to non-road vehicle emissions.

scholarly journals Seasonal Variation and Source Apportionment of Inorganic and Organic Components in PM2.5: Influence of Organic Markers Application on PMF Source Apportionment

2022 ◽  
Author(s):  
Qianqian Xue ◽  
Ying-Ze Tian ◽  
Yang Wei ◽  
Danlin Song ◽  
Fengxia Huang ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Coal Combustion ◽  
Water Soluble ◽  
Secondary Source ◽  
Positive Correlation ◽  
Diesel Vehicles ◽  
Soluble Ions ◽  
Organic Markers ◽  
Polycyclic Aromatic ◽  
Cu And Zn

Abstract PM2.5 samples collected over a 1-year period in a Chinese megacity were analyzed for organic carbon (OC), elemental carbon (EC), water soluble ions, elements and organic markers such as polycyclic aromatic hydrocarbons (PAHs), hopanes, steranes, and n-alkanes. In order to study the applicability of organic markers in source apportionment, this study analyzes the relationship between organic and inorganic components, and four scenarios were implemented by incorporating different combinations of organic and inorganic tracers. A positive correlation of SO42− with 4 rings PAHs can prove that coal burning directly emits a portion of sulfate. A positive correlation of NO3− with 5-7 rings PAHs are found, implying collective impacts from the vehicle source. The concentrations of OC and EC positively correlate with the 5-7 rings PAHs and Cu and Zn, which proves that part of Cu and Zn comes from vehicle emissions. Five factors were identified by incorporating only conventional components, including secondary source (SS, 30%), urban fugitive dust (UFD, 14%), cement dust (CD, 4%), traffic source (TS, 19%) and coal combustion (CC, 14%). Six factors were identified by incorporating conventional components and PAHs, including SS (28%), UFD (15%), CD (4%), CC (13%), gasoline vehicles (GV, 12%) and diesel vehicles (DV, 10%). Eight factors were identified by incorporating conventional components, PAHs, hopanes, and n-alkanes, including SS (26%), UFD (17%), CD (3%), GV (14%), DV (8%), immature coal combustion (ICC, 5%), mature coal combustion (MCC, 10%) and biogenic source (BS, 1%).

scholarly journals Combination of Different Approaches to Infer Local or Regional Contributions to PM2.5 Burdens in Graz, Austria

2020 ◽  
Vol 10 (12) ◽  
pp. 4222
Author(s):  
Bernadette Kirchsteiger ◽  
Magdalena Kistler ◽  
Thomas Steinkogler ◽  
Christopher Herzig ◽  
Andreas Limbeck ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Source Apportionment ◽  
Water Soluble ◽  
The European Union ◽  
Limit Value ◽  
Soluble Ions ◽  
Local Sources ◽  
Polycyclic Aromatic ◽  
Accumulation Of Pollutants ◽  
Short Time

In early 2017 high particulate matter (PM) levels were observed across mid-Europe, including Austria. Here we characterize PM pollution in the city of Graz during January to March 2017, a period with substantial exceedances (34 days) of the European Union (EU) PM10 short time limit value. This study evaluates whether the observed exceedances can be attributed to the accumulation of pollutants emitted by local sources or to a larger scale pollution episode including transport. The analyses are based on the ratios of PM10 concentrations determined at an urban and background site, and the analyses of chemical composition of PM2.5 samples (i.e., water soluble ions, organic and elemental carbon, anhydro-sugars, humic-like substances, aluminum, and polycyclic aromatic hydrocarbons). Source apportionment was realized using a macro-tracer model. Overall, the combination of different approaches (PM10 ratios, chemical composition, and macro-tracer derived source apportionment) enabled a conclusive identification of time periods characterized by the accumulation of emissions from local sources or regional pollution episodes.

scholarly journals Organic aerosol source apportionment by offline-AMS over a full year in Marseille

2017 ◽  
Vol 17 (13) ◽  
pp. 8247-8268 ◽  
Author(s):  
Carlo Bozzetti ◽  
Imad El Haddad ◽  
Dalia Salameh ◽  
Kaspar Rudolf Daellenbach ◽  
Paola Fermo ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Coke Production ◽  
Water Soluble ◽  
Biomass Combustion ◽  
Seasonal Trends ◽  
Soluble Ions ◽  
Yearly Average ◽  
Polycyclic Aromatic ◽  
Field Deployment ◽  
A Minor

Abstract. We investigated the seasonal trends of OA sources affecting the air quality of Marseille (France), which is the largest harbor of the Mediterranean Sea. This was achieved by measurements of nebulized filter extracts using an aerosol mass spectrometer (offline-AMS). In total 216 PM2. 5 (particulate matter with an aerodynamic diameter  <  2.5 µm) filter samples were collected over 1 year from August 2011 to July 2012. These filters were used to create 54 composite samples which were analyzed by offline-AMS. The same samples were also analyzed for major water-soluble ions, metals, elemental and organic carbon (EC ∕ OC), and organic markers, including n-alkanes, hopanes, polycyclic aromatic hydrocarbons (PAHs), lignin and cellulose pyrolysis products, and nitrocatechols. The application of positive matrix factorization (PMF) to the water-soluble AMS spectra enabled the extraction of five factors, related to hydrocarbon-like OA (HOA), cooking OA (COA), biomass burning OA (BBOA), oxygenated OA (OOA), and an industry-related OA (INDOA). Seasonal trends and relative contributions of OA sources were compared with the source apportionment of OA spectra collected from the AMS field deployment at the same station but in different years and for shorter monitoring periods (February 2011 and July 2008). Online- and offline-AMS source apportionment revealed comparable seasonal contribution of the different OA sources. Results revealed that BBOA was the dominant source during winter, representing on average 48 % of the OA, while during summer the main OA component was OOA (63 % of OA mass on average). HOA related to traffic emissions contributed on a yearly average 17 % to the OA mass, while COA was a minor source contributing 4 %. The contribution of INDOA was enhanced during winter (17 % during winter and 11 % during summer), consistent with an increased contribution from light alkanes, light PAHs (fluoranthene, pyrene, phenanthrene), and selenium, which is commonly considered as a unique coal combustion and coke production marker. Online- and offline-AMS source apportionments revealed evolving levoglucosan : BBOA ratios, which were higher during late autumn and March. A similar seasonality was observed in the ratios of cellulose combustion markers to lignin combustion markers, highlighting the contribution from cellulose-rich biomass combustion, possibly related to agricultural activities.

scholarly journals Characteristics of concentrations and chemical compositions for PM<sub>2.5</sub> in the region of Beijing, Tianjin, and Hebei, China

2013 ◽  
Vol 13 (1) ◽  
pp. 863-901 ◽  
Author(s):  
P. S. Zhao ◽  
F. Dong ◽  
D. He ◽  
X. J. Zhao ◽  
W. Z. Zhang ◽  
...  
Keyword(s):  
Coal Combustion ◽  
Urban Areas ◽  
Motor Vehicle ◽  
Water Soluble ◽  
Photochemical Oxidation ◽  
Chemical Compositions ◽  
Soluble Ions ◽  
Secondary Ions ◽  
Water Soluble Ions ◽  
Autumn And Winter

Abstract. In order to study the temporal and spatial variations of PM2.5 and its chemical compositions in the region of Beijing, Tianjin, and Hebei (BTH), PM2.5 samples were collected at four urban sites in Beijing (BJ), Tianjin (TJ), Shijiazhuang (SJZ), and Chengde (CD) and one site at Shangdianzi (SDZ) regional background station over four seasons from 2009 to 2010. The samples were weighted for mass concentrations and analyzed in laboratory for chemical profiles of 19 elements (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, Sr, Ti, V, and Zn), eight water-soluble ions (Na+, NH4+, K+, Mg2+, Ca2+, Cl−, NO3−, and SO42−), and carbon fractions (OC and EC). The concentrations of PM2.5 and its major chemical species were season-dependent and showed spatially similar characteristics in the plain area of BTH. The average annual concentrations of PM2.5 were 71.8–191.2 μg m−3 at five sites, with more than 90 % sampling days exceeded 50 μg m−3 at BJ, TJ, and SJZ. PM2.5 pollution was most serious at SJZ, and the annual concentrations of PM2.5, secondary ions, OC, EC, and most of crustal elements were all highest. Due to stronger photochemical oxidation, the sum of concentrations of secondary ions (NH4+, NO3−, and SO42−) was highest in the summer at SDZ, BJ, TJ, and CD. Analysis of electric charges of water-soluble ions indicated the existence of nitric acid or hydrochloric acid in PM2.5. For all five sites, the concentrations of OC, EC and also secondary organic carbon (SOC) in the spring and summer were lower than those in the autumn and winter. Stable atmosphere and low temperatures appearing more frequently during autumn and winter facilitated the formation of SOC. The sums of crustal elements (Al, Ca, Fe, Mg, Ti, Ba, and Sr) were higher in the spring and autumn owing to more days with blowing or floating dust. The concentrations of heavy metals were at higher levels in the BTH area by comparison with other studies. In Shijiazhuang and Chengde, the PM2.5 pollution was dominated by coal combustion. Motor vehicle exhausts and coal combustion emissions both played important role in Tianjin PM2.5$ pollution. However, motor vehicle exhausts had played more important role in Beijing owing to the reduction of coal consumption and sharply increase of cars in recent years. At SDZ, regional transportation of air pollutants from southern urban areas was significant.

scholarly journals Characteristics of Aerosol during a Severe Haze-Fog Episode in the Yangtze River Delta: Particle Size Distribution, Chemical Composition, and Optical Properties

Atmosphere ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 56 ◽  
Author(s):  
Ankang Liu ◽  
Honglei Wang ◽  
Yi Cui ◽  
Lijuan Shen ◽  
Yan Yin ◽  
...  
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Chemical Composition ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Water Soluble ◽  
Air Masses ◽  
Soluble Ions ◽  
Wide Range ◽  
Water Soluble Ions

Particle size distribution, water soluble ions, and black carbon (BC) concentration in a long-term haze-fog episode were measured using a wide-range particle spectrometer (WPS), a monitor for aerosols and gases (MARGA), and an aethalometer (AE33) in Nanjing from 16 to 27 November, 2018. The observation included five processes of clean, mist, mix, haze, and fog. Combined with meteorological elements, the HYSPLIT model, and the IMPROVE model, we analyzed the particle size distribution, chemical composition, and optical properties of aerosols in different processes. The particle number size distribution (PNSD) in five processes differed: It was bimodal in mist and fog and unimodal in clean, mix, and haze. The particle surface area size distribution (PSSD) in different processes showed a bimodal distribution, and the second peak of the mix and fog processes shifted to a larger particle size at 480 nm. The dominant air masses in five processes differed and primarily originated in the northeast direction in the clean process and the southeast direction in the haze process. In the mist, mix, and fog processes local air masses dominated. NO3− was the primary component of water soluble ions, with the lowest proportion of 45.6% in the clean process and the highest proportion of 53.0% in the mix process. The ratio of NH4+ in the different processes was stable at approximately 23%. The ratio of SO42− in the clean process was 26.2%, and the ratio of other processes was approximately 20%. The average concentration of BC in the fog processes was 10,119 ng·m−3, which was 3.55, 1.80, 1.60, and 1.46 times that in the processes of clean, mist, mix, and haze, respectively. In the different processes, BC was primarily based on liquid fuel combustion. NO3−, SO42−, and BC were the main contributors to the atmospheric extinction coefficient and contributed more than 90% in different processes. NO3− contributed 398.43 Mm−1 in the mix process, and SO42− and BC contributed 167.90 Mm−1 and 101.19 Mm−1, respectively, during the fog process.

scholarly journals Synthetic Approaches, Modification Strategies and the Application of Quantum Dots in the Sensing of Priority Pollutants

2021 ◽  
Vol 11 (24) ◽  
pp. 11580
Author(s):  
Rodney Maluleke ◽  
Oluwatobi Samuel Oluwafemi
Keyword(s):  
Quantum Dots ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Organic Pollutants ◽  
Aromatic Hydrocarbons ◽  
Aromatic Compounds ◽  
Water Soluble ◽  
Sensing Applications ◽  
Wide Range ◽  
Polycyclic Aromatic ◽  
Nitro Aromatic

Polycyclic aromatic hydrocarbons (PAHs) and nitro-aromatic compounds (NACs) are two classifications of environmental pollutants that have become a source of health concerns. As a result, there have been several efforts towards the development of analytical methods that are efficient and affordable that can sense these pollutants. In recent decades, a wide range of techniques has been developed for the detection of pollutants present in the environment. Among these different techniques, the use of semiconductor nanomaterials, also known as quantum dots, has continued to gain more attention in sensing because of the optical properties that make them useful in the identification and differentiation of pollutants in water bodies. Reported studies have shown great improvement in the sensing of these pollutants. This review article starts with an introduction on two types of organic pollutants, namely polycyclic aromatic hydrocarbons and nitro-aromatic explosives. This is then followed by different quantum dots used in sensing applications. Then, a detailed discussion on different groups of quantum dots, such as carbon-based quantum dots, binary and ternary quantum dots and quantum dot composites, and their application in the sensing of organic pollutants is presented. Different studies on the comparison of water-soluble quantum dots and organic-soluble quantum dots of a fluorescence sensing mechanism are reviewed. Then, different approaches on the improvement of their sensitivity and selectivity in addition to challenges associated with some of these approaches are also discussed. The review is concluded by looking at different mechanisms in the sensing of polycyclic aromatic hydrocarbons and nitro-aromatic compounds.

Effects of vehicle type and fuel quality on the exposure risk of toxic emissions from diesel vehicles

2009 ◽  
Vol 6 (3) ◽  
pp. 260 ◽  
Author(s):  
Peter F. Nelson
Keyword(s):  
Cancer Risk ◽  
Diesel Exhaust ◽  
Fine Particles ◽  
Health Impacts ◽  
Fuel Quality ◽  
Toxic Compounds ◽  
Toxic Species ◽  
Vehicle Type ◽  
Diesel Vehicles ◽  
Wide Range

Environmental Context. Motor vehicle emissions of toxic chemicals are a major contributor to urban air pollution, and to potential human health problems. Diesel vehicles have historically been major sources of smoke and fine particles that contain a wide range of toxic species. In this study the effects of vehicle type and fuel quality on the cancer forming risk of toxic compounds in diesel exhaust are determined. It is found that the major risk is due to toxic compounds such as benzene formed during fuel combustion in the vehicle engine. Abstract. Diesel vehicles are an important source of emission of air pollutants, particularly toxic compounds with potential health impacts. Current developments in engine design and fuel quality are expected to reduce these emissions, but many older vehicles will make a major contribution to urban pollutant concentrations and related health impacts for many years. In this study the relative inhalation risk of emissions of a range of toxic compounds are reported using data from a study of in-service vehicles driven through urban drive cycles using a range of diesel fuel formulations. The fuels ranged in sulfur content from 24 to 1700 ppm, and in total aromatics from 7.7 to 33 mass%. Effects of vehicle type and fuel composition on the risk of emissions of a range of toxic species are reported. The results show that the inhalation cancer risk is dominated for most of the vehicles and the testing modes by emissions of the combustion derived products, particularly benzene, naphthalene, and formaldehyde, and not by the polycyclic aromatic hydrocarbons such as benzo(a)pyrene. Based on the relative risk represented by these toxic species, improved fuel quality does not result in significant reductions in the relative inhalation cancer risk. However, this conclusion may be affected by additional toxic species and fine particles present in diesel exhaust, which were not included in this study.

scholarly journals The relative importance of tailpipe and non-tailpipe emissions on the oxidative potential of ambient particles in Los Angeles, CA

2016 ◽  
Vol 189 ◽  
pp. 361-380 ◽  
Author(s):  
Farimah Shirmohammadi ◽  
Sina Hasheminassab ◽  
Dongbin Wang ◽  
James J. Schauer ◽  
Martin M. Shafer ◽  
...  
Keyword(s):  
Los Angeles ◽  
Chemical Constituents ◽  
Univariate Analysis ◽  
Water Soluble ◽  
Crustal Material ◽  
Relative Importance ◽  
Oxidative Potential ◽  
Carbonaceous Species ◽  
Soluble Ions ◽  
Polycyclic Aromatic

This study examines the associations between the oxidative potential of ambient PM2.5and PM0.18, measured by means of the dithiothreitol (DTT) assay, and their chemical constituents and modeled sources. Particulate matter (PM) samples were collected from 2012–2013 in Central Los Angeles (LA) and 2013–2014 in Anaheim, California, USA. Detailed chemical analyses of the PM samples, including carbonaceous species, inorganic elements and water-soluble ions, were conducted. Univariate analysis indicated a high correlation (R> 0.60) between the DTT activity and the concentrations of carbonaceous species at both sites. The strongest correlations were observed between DTT and organic tracers of primary vehicle tailpipe emissions including polycyclic aromatic hydrocarbons (PAHs) and hopanes as well as EC, with higher correlations for PM0.18versusPM2.5components. Moreover, metals and trace elements (e.g., Ba, Cu, Fe, Mn, Pb and Sb) in both size ranges were also associated with DTT activity. Multiple linear regression (MLR) analysis was performed on DTT activity and PM sources identified by a Molecular Marker-Chemical Mass Balance (MM-CMB) model (i.e.major carbonaceous sources: vehicle tailpipe emissions, wood smoke, primary biogenic and secondary organic carbon) together with other typical sources of ambient PM (i.e.crustal material, vehicular abrasion, secondary ions and sea salt). Overall, our findings illustrate the relative importance of different traffic sources on the oxidative potential of ambient PM. Despite major reductions of tailpipe emissions, the lack of similar reductions (and possibly an increase) in non-tailpipe emissions makes them an important source of traffic-related PM in Los Angeles and their increasing role in the overall PM toxicity raises concerns for public health.

scholarly journals Chemical characteristics of cloud water and the impacts on aerosol properties at a subtropical mountain site in Hong Kong SAR

2020 ◽  
Vol 20 (1) ◽  
pp. 391-407 ◽  
Author(s):  
Tao Li ◽  
Zhe Wang ◽  
Yaru Wang ◽  
Chen Wu ◽  
Yiheng Liang ◽  
...  
Keyword(s):  
Hong Kong ◽  
Gas Phase ◽  
Carboxylic Acids ◽  
Carbonyl Compounds ◽  
Cloud Water ◽  
Water Soluble ◽  
Chemical Compositions ◽  
Soluble Ions ◽  
Hong Kong Sar ◽  
Aerosol Properties

Abstract. To investigate the cloud water chemistry and the effects of cloud processing on aerosol properties, comprehensive field observations of cloud water, aerosols, and gas-phase species were conducted at a mountaintop site in Hong Kong SAR in October and November 2016. The chemical composition of cloud water including water-soluble ions, dissolved organic matter (DOM), carbonyl compounds (refer to aldehydes and acetone), carboxylic acids, and trace metals was quantified. The measured cloud water was very acidic with a mean pH of 3.63, as the ammonium (174 µeq L−1) was insufficient for neutralizing the dominant sulfate (231 µeq L−1) and nitrate (160 µeq L−1). Substantial DOM (9.3 mgC L−1) was found in cloud water, with carbonyl compounds and carboxylic acids accounting for 18 % and 6 % in carbon molar concentrations, respectively. Different from previous observations, concentrations of methylglyoxal (19.1 µM; µM is equal to µmol L−1) and glyoxal (6.72 µM) were higher than that of formaldehyde (1.59 µM). The partitioning of carbonyls between cloud water and the gas phase was also investigated. The measured aqueous fractions of dicarbonyls were comparable to the theoretical estimations, while significant aqueous-phase supersaturation was found for less soluble monocarbonyls. Both organics and sulfate were significantly produced in cloud water, and the aqueous formation of organics was more enhanced by photochemistry and under less acidic conditions. Moreover, elevated sulfate and organics were measured in the cloud-processed aerosols, and they were expected to contribute largely to the increase in droplet-mode aerosol mass fraction. This study demonstrates the significant role of clouds in altering the chemical compositions and physical properties of aerosols via scavenging and aqueous chemical processing, providing valuable information about gas–cloud–aerosol interactions in subtropical and coastal regions.

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