Mass size distribution of carbon in atmospheric humic-like substances and water soluble organic carbon for an urban environment

Temporal variations of the abundance and optical properties of water soluble Humic-Like Substances (HULIS) in PM2.5 at Guangzhou, China

“…The result was consistent with the conclusion that SOA is recognized as an important source of HULIS El Haddad et al, 2009;Kuang et al, 2015;Salma et al, 2013Salma et al, , 2007. In many studies, NO 3 − , SO 4 2− and NH 4 + , in PM 2.5 aerosols are recognized as resulting from secondary formation, so they are usually grouped as secondary water soluble ions (SWSI) (Behera et al, 2013;Li et al, 2013;Milford et al, 2013;Tsai et al, 2013).…”

“…However, in these studies the HULIS/PM 2.5 ratios were slightly higher, with an annual average of 8.5-10.2% (Kuang et al, 2015;Lin et al, 2010a), which may be ascribed to differences in the HULIS isolation and quantification methods between studies and/or the differences of sources due to sampling times and sites. As a comparison, relatively lower contributions (1.5-3.6%) of HULIS to total suspended particles (TSP) were found in our previous study , suggesting that HULIS is enriched in fine particle fractions (Lin et al, 2010b;Salma et al, 2013).…”

“…The sources of HULIS in atmospheric aerosols are very complex, and mainly include primary emissions such as biomass burning and secondary formation due to the photochemical reactions of volatile organic compounds (i.e., isoprene, monoterpenes) (Lin et al, 2010b;Salma et al, 2012). The relative contributions of various sources may vary in different seasons.…”

“…These organics were found to have similar physical and chemical properties (e.g., acidity, UV-Vis absorbance, fluorescence, Fouriertransformed infrared (FTIR) and nuclear magnetic resonance (NMR) spectra) to those of naturally occurring humic substances Zheng et al, 2013), and are therefore referred to as Humic-Like Substances (HULIS). HULIS are important contributors to the mass of organic aerosol, comprising up to 60% (in terms of carbon content) of the water soluble organic matter (WSOM) (Baduel et al, , 2010Fan et al, 2013Fan et al, , 2012Krivacsy et al, 2008;Lin et al, 2010b;Salma et al, 2012Salma et al, , 2007Song et al, 2012;Zheng et al, 2013). Moreover, many studies have shown that HULIS may play a significant role in the atmospheric troposphere; for example, they can influence the hygroscopic growth of aerosols and the formation of cloud condensation nuclei (Dinar et al, 2006), radiation balance (Lukacs et al, 2007;Ramanathan et al, 2005), and atmospheric chemistry processes (Kiss et al, 2005).…”

Comprehensive characterization of humic-like substances in smoke PM<sub>2.5</sub> emitted from the combustion of biomass materials and fossil fuels

“…These atmospheric HULIS materials are found ubiquitously in various environments, and are derived from various sources. Their possible sources include biomass burning (BB; Feczko et al, 2007;Baduel et al, 2010;Lin et al, 2010a), vehicular emissions (El Haddad et al, 2009), marine emissions (Krivacsy et al, 2008), the oxidation of soot Li et al, 2013Li et al, , 2015, and secondary processes via the transformation of gas-and condensed-phase species by chemical reactions (Salma et al, 2007;Baduel et al, 2010;Salma et al, 2013).…”