Sources and oxidative potential of water-soluble humic-like substances (HULIS<sub>WS</sub>) in fine particulate matter (PM<sub>2.5</sub>) in Beijing
Water-soluble humic-like substances (HULIS<sub>WS</sub>) are a major redox-active component of ambient fine particulate matter (PM<sub>2.5</sub>); however, information on their sources and associated redox activity is limited. In this study, HULIS<sub>WS</sub>...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-04-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/18/5607/2018/acp-18-5607-2018.pdf |
| Summary: | Water-soluble humic-like substances (HULIS<sub>WS</sub>) are a
major redox-active component of ambient fine particulate matter
(PM<sub>2.5</sub>); however, information on their sources and associated redox
activity is limited. In this study, HULIS<sub>WS</sub> mass concentration, various
HULIS<sub>WS</sub> species, and dithiothreitol (DTT) activity of HULIS<sub>WS</sub> were
quantified in PM<sub>2.5</sub> samples collected during a 1-year period in
Beijing. Strong correlation was observed between HULIS<sub>WS</sub> and DTT
activity; both exhibited higher levels during the heating season than during
the nonheating season. Positive matrix factorization analysis of both
HULIS<sub>WS</sub> and DTT activity was performed. Four combustion-related
sources, namely coal combustion, biomass burning, waste incineration, and
vehicle exhausts, and one secondary factor were resolved. In particular,
waste incineration was identified as a source of HULIS<sub>WS</sub> for the first
time. Biomass burning and secondary aerosol formation were the major
contributors ( > 59 %) to both HULIS<sub>WS</sub> and associated DTT
activity throughout the year. During the nonheating season, secondary
aerosol formation was the most important source, whereas during the heating
season, the predominant contributor was biomass burning. The four
combustion-related sources accounted for > 70 % of HULIS<sub>WS</sub>
and DTT activity, implying that future reduction in PM<sub>2.5</sub> emissions
from combustion activities can substantially reduce the HULIS<sub>WS</sub> burden
and their potential health impact in Beijing. |
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| ISSN: | 1680-7316 1680-7324 |