Molecular characterization of organic aerosols in the Kathmandu Valley, Nepal: insights into primary and secondary sources

被引：40

作者：

Wan, Xin ^{[1
,8
]}

Kang, Shichang ^{[2
,7
]}

Rupakheti, Maheswar ^{[3
,4
]}

Zhang, Qianggong ^{[1
,7
]}

Tripathee, Lekhendra ^{[2
]}

Guo, Junming ^{[2
]}

Chen, Pengfei ^{[2
]}

Rupakheti, Dipesh ^{[2
]}

Panday, Arnico K. ^{[5
]}

Lawrence, Mark G. ^{[3
]}

Kawamura, Kimitaka ^{[6
]}

Cong, Zhiyuan ^{[1
,7
]}

机构：

[1] Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Tibetan Environm Changes & Land Surface P, Beijing 100101, Peoples R China

[2] Chinese Acad Sci, Northwest Inst Ecoenvironm & Resources, State Key Lab Cryospher Sci, Lanzhou 730000, Gansu, Peoples R China

[3] IASS, D-14467 Potsdam, Germany

[4] Himalayan Sustainabil Inst HIMSI, Kathmandu, Nepal

[5] Int Ctr Integrated Mt Dev ICIMOD, Khumaltar, Lalitpur, Nepal

[6] Chubu Univ, Chubu Inst Adv Studies, Kasugai, Aichi 4878501, Japan

[7] CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China

[8] Univ Chinese Acad Sci, Beijing 100039, Peoples R China

来源：

ATMOSPHERIC CHEMISTRY AND PHYSICS | 2019年 / 19卷 / 05期

基金：

中国博士后科学基金; 中国国家自然科学基金;

关键词：

POLYCYCLIC AROMATIC-HYDROCARBONS; BIOMASS BURNING AEROSOLS; HIGH-ALTITUDE SITE; ATMOSPHERIC AEROSOLS; CARBONACEOUS AEROSOLS; SOURCE APPORTIONMENT; PARTICULATE MATTER; DICARBOXYLIC-ACIDS; SEASONAL-VARIATION; SIZE DISTRIBUTION;

D O I：

10.5194/acp-19-2725-2019

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

Organic atmospheric aerosols in the Hindu Kush-Himalayas-Tibetan Plateau region are still poorly characterized. To better understand the chemical characteristics and sources of organic aerosols in the foothill region of the central Himalaya, the atmospheric aerosol samples were collected in Bode, a suburban site of the Kathmandu Valley (KV) over a 1-year period from April 2013 to April 2014. Various molecular tracers from specific sources of primary organic aerosols (POAs) and secondary organic aerosols (SOAs) were determined. Tracer-based estimation methods were employed to apportion contributions from each source. The concentrations of organic carbon (OC) and elemental carbon (EC) increased during winter with a maximum monthly average in January. Levoglucosan (a molecular tracer for biomass burning, BB) was observed as the dominant species among all the analyzed organic tracers and its annual average concentration was 788 +/- 685 ng m(-3) (ranging from 58.8 to 3079 ng m(-3)). Isoprene-SOA (I-SOA) represented a high concentration among biogenic-SOA tracers. For the seasonality, anhydrosugars, phenolic compounds, resin acid, and aromatic SOA tracer showed similar seasonal variations with OC and EC while monosaccharides, sugar alcohols, and I-SOA tracers showed lower levels during winter. BB contributed a significant fraction to OC, averaging 24.9% +/- 10.4% during the whole year, and up to 36.3% +/- 10.4% in the post-monsoon season. On an annual average basis, anthropogenic toluene-derived secondary OC accounted for 8.8% and biogenic secondary OC contributed 6.2% to total OC. The annual contribution of fungal spores to OC was 3.2% with a maximum during the monsoon season (5.9 %). For plant debris, it accounted for 1.4% of OC during the monsoon. Therefore, OC is mainly associated with BB and other anthropogenic activity in the KV. Our findings are conducive to designing effective measures to mitigate the heavy air pollution and its impacts in the KV and surrounding area.

引用

页码：2725 / 2747

页数：23

共 106 条

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