Size-Resolved Anhydrosugar Composition in Smoke Aerosol from Controlled Field Burning of Rice Straw

Abstract

A field study was conducted to determine the effects of ambient conditions and burning practices of rice fields in Taiwan on the chemical and physical characteristics of the smoke aerosol. Rice straw was burned on an actual rice field under typical conditions and smoke particles were collected immediately downwind of the field over the full particle size spectrum. Here we present size distributions of levoglucosan, a common molecular tracer for biomass burning, as well as detailed concentration patterns of three anhydrosugars, including mannosan, and galactosan, in addition to smoke aerosol concentrations of inorganic ions and carbonaceous species. The generated smoke aerosol was characterized by a high OC/EC ratio (10) and a large fraction of potassium (K + ) and chloride (Cl -) ions at a Cl -/K + ratio of 2. Levoglucosan showed a distinct bimodal distribution in the smoke particles with a large fraction (up to 56%) of the total levoglucosan mass observed in very large particles (PM >10 ). The prevailing ambient conditions (such as relatively high humidity), atmospheric processes (e.g., particle coagulation, hygroscopic growth, and deposition), the specific burning practices of rice fields in Taiwan (slow burning of straw spread in thin layers on the ground), as well as the inherent properties of rice straw likely influenced the particle size characteristics of the smoke tracer. Moreover, the relative abundance of the three biomass burning tracers showed a unique pattern (in good agreement with previous chamber burn measurements): levoglucosanto-mannosan ratios were distinctly higher (with an average value of 27) than those observed for other types of biomass, such as softwood, hard wood, peat, or leaves, in previous studies. Such chemical fingerprint may be used in source apportionment studies for the assessment of contributions from the combustion of specific types of biomass.

Anthropogenic and biogenic organic compounds in summertime fine aerosols (PM2.5) in Beijing, China

“…At Yufa, this ratio was slightly higher, ranging from 8.2 to 16.5 (10.8). The higher L/M ratios observed at Yufa than PKU agree with those for straw burning smokes (Sheesley et al, 2003;Engling et al, 2009). Hall et al (2012) used a combustion chamber to burn sugarcane in controlled conditions and calculated the emission of several compounds per unit of mass, including levoglucosan and mannosan.…”

Organic compounds in PM2.5 emitted from fireplace and woodstove combustion of typical Portuguese wood species

“…Differences in the L/M ratio in smoke from softwood and hardwood/grass combustion (w5 versus w10e20, respectively) can further support discrimination between inputs from these combustion sources to the atmosphere (Louchouarn et al, 2009;and references therein). Herbaceous tissues can produce relatively high L/M ratios, in the range from 25 to 50 (Engling et al, 2009). In the present study, lower ratios than those reported for soft-and hardwood smoke were obtained.…”

Primary biological aerosol particles in the atmosphere: a review

“…Molecular techniques 3.3.1.1. Chemical tracers: Chemical tracers, such as the sugar alcohols mannitol and arabitol, can be used to not only assess the abundance of PBAP, especially fungal spores in air particulate matter, but also characterise other aerosol types (Hensel and Petzhold, 1995;Graham et al, 2003;Graham et al, 2004;Lau et al, 2006;Elbert et al, 2007;Yttri et al, 2007;Bauer et al, 2008a;Engling et al, 2009;IInuma et al, 2009;Burshtein et al, 2011). A number of other chemical tracers have been used as proxies for various types of biological aerosol particles, such as endotoxins, mycotoxins, glucan, ergosterol, extracellular polymeric substances, carbohydrates, proteins, peptides, sugars and adenosine triphospate (ATP).…”