Seasonal characteristics of oxalic acid and related SOA in the free troposphere of Mt. Hua, central China: Implications for sources and formation mechanisms

Meng, Jingjing; Wang, Gehui; Li, Jianjun; Cheng, Chunlei; Ren, Yin; Huang, Yao; Cheng, Yuanming; Cao, Junji; Zhang, Ting

doi:10.1016/j.scitotenv.2014.04.086

Cited by 53 publications

(47 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5), indicating a strong association of oxalic acid formation with photochemical reactions. Malonic acid is another product of photochemical oxidation of organic compounds (Kawamura and Ikushima, 1993;Wang et al, 2012;Meng et al, , 2014. In our campaign, malonic-acid-containing particles had diurnal trends similar to oxalic acid particles and O 3 concentration.…”

Section: Photochemical Production Of Oxalic Acid In Summersupporting

confidence: 52%

Mixing state of oxalic acid containing particles in the rural area of Pearl River Delta, China: implications for the formation mechanism of oxalic acid

Cheng

Chan

et al. 2017

Atmos. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

Abstract. The formation of oxalic acid and its mixing state in atmospheric particulate matter (PM) were studied using a single-particle aerosol mass spectrometer (SPAMS) in the summer and winter of 2014 in Heshan, a supersite in the rural area of the Pearl River Delta (PRD) region in China. Oxalic-acid-containing particles accounted for 2.5 and 2.7 % in total detected ambient particles in summer and winter, respectively. Oxalic acid was measured in particles classified as elemental carbon (EC), organic carbon (OC), elemental and organic carbon (ECOC), biomass burning (BB), heavy metal (HM), secondary (Sec), sodium-potassium (NaK), and dust. Oxalic acid was found predominantly mixing with sulfate and nitrate during the whole sampling period, likely due to aqueous-phase reactions. In summer, oxalic-acid-containing particle number and ozone concentration followed a very similar trend, which may reflect the significant contribution of photochemical reactions to oxalic acid formation. The HM particles were the most abundant oxalic acid particles in summer and the diurnal variations in peak area of iron and oxalic acid show opposite trends, which suggests a possible loss of oxalic acid through the photolysis of iron oxalatocomplexes during the strong photochemical activity period. In wintertime, carbonaceous particles contained a substantial amount of oxalic acid as well as abundant carbon clusters and BB markers. The general existence of nitric acid in oxalic-acid-containing particles indicates an acidic environment during the formation process of oxalic acid. The peak areas of nitrate, sulfate and oxalic had similar temporal change in the carbonaceous type oxalic acid particles, and the organosulfate-containing oxalic acid particles correlated well with total oxalic acid particles during the haze episode, which suggests that the formation of oxalic acid is closely associated with the oxidation of organic precursors in the aqueous phase.

show abstract

Section: Photochemical Production Of Oxalic Acid In Summersupporting

confidence: 52%

Mixing state of oxalic acid containing particles in the rural area of Pearl River Delta, China: implications for the formation mechanism of oxalic acid

Cheng

Chan

et al. 2017

Atmos. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Oxalic acid is a secondary product formed from the aqueous-phase oxidation of water-soluble organic precursors and ubiquitously exists in the troposphere. Like other pollutants, oxalic acid has been also shown to occur in large abundance in China (Wang et al, 2012;Meng et al, 2014;Kawamura and Bikkina, 2016).…”

Section: Field Measurements Of Wsom In Chinamentioning

confidence: 99%

Particle acidity and sulfate production during severe haze events in China cannot be reliably inferred by assuming a mixture of inorganic salts

et al. 2018

Self Cite

View full text Add to dashboard Cite

Abstract. Atmospheric measurements showed rapid sulfate formation during severe haze episodes in China, with fine particulate matter (PM) consisting of a multi-component mixture that is dominated by organic species. Several recent studies using the thermodynamic model estimated the particle acidity and sulfate production rate, by treating the PM exclusively as a mixture of inorganic salts dominated by ammonium sulfate and neglecting the effects of organic compounds. Noticeably, the estimated pH and sulfate formation rate during pollution periods in China were highly conflicting among the previous studies. Here we show that a particle mixture of inorganic salts adopted by the previous studies does not represent a suitable model system and that the acidity and sulfate formation cannot be reliably inferred without accounting for the effects of multi-aerosol compositions during severe haze events in China. Our laboratory experiments show that SO 2 oxidation by NO 2 with NH 3 neutralization on fine aerosols is dependent on the particle hygroscopicity, phase-state, and acidity. Ammonium sulfate and oxalic acid seed particles exposed to vapors of SO 2 , NO 2 , and NH 3 at high relative humidity (RH) exhibit distinct size growth and sulfate formation. Aqueous ammonium sulfate particles exPublished by Copernicus Publications on behalf of the European Geosciences Union. G. Wang et al.: Rapid formation of sulfate in Chinese haze periodshibit little sulfate production, in contrast to aqueous oxalic acid particles with significant sulfate production. Our field measurements demonstrate significant contribution of watersoluble organic matter to fine PM in China and indicate that the use of oxalic acid in laboratory experiments is representative of ambient organic dominant aerosols. While the particle acidity cannot be accurately determined from field measurements or calculated using the thermodynamic model, our results reveal that the pH value of ambient organics-dominated aerosols is sufficiently high to promote efficient SO 2 oxidation by NO 2 with NH 3 neutralization under polluted conditions in China.

show abstract

“…The method of analyzing PM 2.5 samples for dicarboxylic acids, ketocarboxylic acids and α-dicarbonyl has been reported elsewhere (Wang et al, 2002Meng et al, 2014;Cheng et al, 2015). Briefly, one eighth of the filter was extracted with Milli-Q water, concentrated to near dryness, and reacted with 14 % BF 3 /butanol at 100 • C for 1 h to convert the aldehyde group into dibutoxy acetal and the carboxyl group into butyl ester.…”

Section: Dicarboxylic Acids Keto-carboxylic Acids and α-Dicarbonylsmentioning

confidence: 99%

Concentrations and stable carbon isotope compositions of oxalic acid and related SOA in Beijing before, during, and after the 2014 APEC

Wang

Gao

et al. 2017

Atmos. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

Abstract. To ensure good air quality for the 2014 AsiaPacific Economic Cooperation (APEC) summit, stringent emission controls were implemented in Beijing and its surrounding regions, leading to a significant reduction in PM 2.5 loadings. To investigate the impact of the emission controls on aerosol chemistry, high-volume PM 2.5 samples were collected in Beijing from 8 October to 24 November 2014 and determined for secondary inorganic aerosols (SIA, i.e., SO 2− 4 , NO − 3 , and NH + 4 ), dicarboxylic acids, keto-carboxylic acid, and α-dicarbonyls, as well as stable carbon isotope composition of oxalic acid (C 2 ). Our results showed that SIA, C 2 , and related secondary organic aerosols in PM 2.5 during APEC were 2-4 times lower than those before APEC, which is firstly ascribed to the strict emission control measures and secondly attributed to the relatively colder and drier conditions during the event that are unfavorable for secondary aerosol production.C 2 in the polluted air masses, which mostly occurred before APEC, are abundant and enriched in 13 C. On the contrary, C 2 in the clean air masses, which mostly occurred during APEC, is much less abundant but still enriched in 13 C. In the mixed type of clean and polluted air masses, which mostly occurred after APEC, C 2 is lower than that before APEC but higher than that during APEC and enriched in lighter 12 C. A comparison on chemical composition of fine particles and δ 13 C values of C 2 in two events that are characterized by high loadings of PM 2.5 further showed that after APEC SIA and the total detected organic compounds (TDOC) are much less abundant and fine aerosols are enriched with primary organics and relatively fresh, compared with those before APEC.

show abstract

Seasonal characteristics of oxalic acid and related SOA in the free troposphere of Mt. Hua, central China: Implications for sources and formation mechanisms

Cited by 53 publications

References 57 publications

Mixing state of oxalic acid containing particles in the rural area of Pearl River Delta, China: implications for the formation mechanism of oxalic acid

Mixing state of oxalic acid containing particles in the rural area of Pearl River Delta, China: implications for the formation mechanism of oxalic acid

Particle acidity and sulfate production during severe haze events in China cannot be reliably inferred by assuming a mixture of inorganic salts

Concentrations and stable carbon isotope compositions of oxalic acid and related SOA in Beijing before, during, and after the 2014 APEC

Contact Info

Product

Resources

About