Volume 14, No. 6, October 2014, Pages 1653-1664 PDF(313 KB)
Seasonal and Diurnal Characteristics of Carbonyls in Urban Air in Qinzhou, China
Song-Jun Guo1, Mei Chen2, Xiao-Lang He1, Wei-Wei Yang1, Ji-Hua Tan3
1 School of Environment, Guangxi University, Nanning, China
2 Agricultural and Mechanical College, Nanning University, Nanning, China
3 College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
- Characteristics of carbonyls in urban air in Qinzhou were studied.
- Formaldehyde, acetaldehyde and acetone were most abundant carbonyls.
- Both formaldehyde and acetaldehyde showed higher levels in the nighttime.
- Higher C1/C2 ratios in summer and lower C2/C3 ratios in winter were observed.
- Barbecue emission, straw burning and solvent usage were the significant sources.
Ambient carbonyls in urban air in Qinzhou were studied form October 2011 to July 2012 to investigate their distribution characteristics and sources. Acetaldehyde (8.04 ± 9.00 µg/m3), formaldehyde (6.70 ± 6.36 µg/m3) and acetone (2.43 ± 2.81 µg/m3) were three most abundant carbonyls, accounting for ~90% of the seven carbonyls identified. Concentrations of most carbonyls showed significantly higher levels in spring and summer than those in autumn and winter. Seasonal and diurnal variations indicated that formaldehyde and acetaldehyde were related to barbecue emissions and photochemical loss, while solvent usage was responsible for acetone. The average C1/C2 ratio was higher (1.92) in summer than that during other seasons (0.52–1.78), implying the positive impact of photochemical loss or formation; and a significantly lower C2/C3 ratio (2.57) was observed in winter than during other seasons (12.47–52.82), suggesting significant emissions from straw burning and barbecues. Formaldehyde and acetaldehyde were the two major contributors (63–97%) to O3 formation, particularly in spring and summer.
Formaldehyde; Acetaldehyde; Barbecue emission; Straw burning emission; Qinzhou.