Volatility and mixing states of ultrafine particles from biomass burning

• Published in: Journal of hazardous materials Vol. 205-206; pp. 189 - 197
• Main Authors: Maruf Hossain, A.M.M., Park, Seungho, Kim, Jae-Seok, Park, Kihong
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 29.02.2012
• Subjects: Agriculture - methods; Air Pollutants - analysis; Biomass; Biomass burning; Black carbon; Carbon - analysis; Fires; Organic carbon; Oryza; Particle Size; Particulate Matter - analysis; Pinus; Quercus; Temperature; Ultrafine particles; Volatilization; VTDMA (volatility tandem differential mobility analyzer); Organic carbon; Ultrafine particles; VTDMA (volatility tandem differential mobility analyzer); Black carbon; Biomass burning
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2011.12.061

► Size distribution, volatility, and mixing states of ultrafine particles emitted from rice straw, oak, and pine burning under different burning conditions were investigated. ► Smoldering combustion emitted larger mode particles in higher numbers than smaller mode particles, while the converse was true for flaming combustion. ► While the flaming combustion and open burning results imply there is internal mixing of OC and BC, smoldering combustion in rice straw produced ultrafine particles devoid of BC. ► Mixing state of ultrafine particles from biomass burning can alter the single scattering albedo, and might even change the sign of radiative forcing. Fine and ultrafine carbonaceous aerosols produced from burning biomasses hold enormous importance in terms of assessing radiation balance and public health hazards. As such, volatility and mixing states of size-selected ultrafine particles (UFP) emitted from rice straw, oak, and pine burning were investigated by using volatility tandem differential mobility analyzer (VTDMA) technique in this study. Rice straw combustion produced unimodal size distributions of emitted aerosols, while bimodal size distributions from combustions of oak (hardwood) and pine (softwood) were obtained. A nearness of flue gas temperatures and a lower CO ratio of flaming combustion (FC) to smoldering combustion (SC) were characteristic differences found between softwood and hardwood. SC emitted larger mode particles in higher numbers than smaller mode particles, while the converse was true for FC. Rice straw open burning UFPs exhibited a volatilization behavior similar to that between FC and SC. In addition, internal mixing states were observed for size-selected UFPs in all biomasses for all combustion conditions, while external mixing states were only observed for rice straw combustion. Results for FC and open burning suggested there was an internal mixing of volatile organic carbon (OC) and non-volatile core (e.g., black carbon (BC)), while the SC in rice straw produced UFPs devoid of non-volatile core. Also, it was found that volatility of constituting OC in FC and SC particles was different.