Multisize particulate matter and volatile organic compounds in arid and semiarid areas of Northwest China

Xi Zhou; Zhongqin Li; Tingjun Zhang; Feiteng Wang; Yan Tao; Xin Zhang

doi:10.1016/j.envpol.2022.118875

Multisize particulate matter and volatile organic compounds in arid and semiarid areas of Northwest China

Environ Pollut. 2022 May 1:300:118875. doi: 10.1016/j.envpol.2022.118875. Epub 2022 Jan 21.

Authors

Xi Zhou¹, Zhongqin Li², Tingjun Zhang³, Feiteng Wang⁴, Yan Tao³, Xin Zhang⁴

Affiliations

¹ Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China; State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources; Tianshan Glaciological Station, Chinese Academy of Sciences, Lanzhou, 730000, China.
² State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources; Tianshan Glaciological Station, Chinese Academy of Sciences, Lanzhou, 730000, China; College of Sciences, Shihezi University, Xinjiang, 832000, China; College of Geography and Environmental Science, Northwest Normal University, Lanzhou, 730000, China. Electronic address: lizq@lzb.ac.cn.
³ Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China.
⁴ State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources; Tianshan Glaciological Station, Chinese Academy of Sciences, Lanzhou, 730000, China.

PMID: 35074457
DOI: 10.1016/j.envpol.2022.118875

Abstract

To investigate the chemical components, sources, and interactions of particulate matter (PM) and volatile organic compounds (VOCs), a field campaign was implemented during the spring of 2018 in nine cities in northwestern (NW) China. PM was mainly contributed by organic matter and water-soluble inorganic ions (41% for PM₁₀ and approximately 60% for PM_2.5 and PM₁). Two typical haze patterns were observed: anthropogenic pollution type (AP-type), wherein contributions of sulfate, nitrate, and ammonium (SNA) increased, and dust pollution type (DP-type), wherein contributions of Ca²⁺ increased and SNA decreased. Source appointment suggested that regional sources contributed close to half to PM_2.5 pollution (40% for AP-type and 50% for DP-type). Thus, sources from regional transport are also important for haze and dust pollution. The ranking of VOC concentrations was methanol > acetaldehyde > formic acid + ethanol > acetone. Compared with other cities, there are higher oxygenated VOCs (OVOCs) and lower aromatics in NW China. The relationships between VOCs and PM were discussed. The dominating secondary organic aerosols (SOA) formation potential precursors were C₁₀-aromatics, xylene, and styrene under low-nitrogen oxide (NOx) conditions, and benzene, C₁₀-aromatics, and toluene dominated under high-NOx conditions. The quadratic polynomial was the most suitable fitting model for their correlation, and the results suggested that VOC oxidations explained 6.1-10.8% and 9.9-20.7% of SOA formation under high-NOx and low-NOx conditions, respectively.

Keywords: Black carbon; NW China; PTR-MS; Particulate matter; Volatile organic compounds.

MeSH terms

Aerosols / analysis
Air Pollutants* / analysis
China
Environmental Monitoring
Particulate Matter / analysis
Seasons
Volatile Organic Compounds* / analysis

Substances

Aerosols
Air Pollutants
Particulate Matter
Volatile Organic Compounds