Source Profiles of Volatile Organic Compounds from Biomass Burning in Yangtze River Delta, China

The volatile organic compounds (VOCs) associated with biomass burning were characterized in the Yangtze River Delta of China, including two types of burning conditions (stove burning and field burning) and five typical kinds of biomass (straws of rice, wheat, bean and rape, and wood). According to the results, the VOC emission factors of straw burning ranged from 2.08 g/kg to 6.99 g/kg with an average of (4.89 +/- 1.70) g/kg, compared to 0.98 g/kg for wood burning. Some differences in VOC composition were observed with the burning of different biomasses. Oxygenated VOC (o-VOC) were the largest contributors to the mass concentration of measured VOCs from straw burning, with a proportion of 49.4%, followed by alkenes 21.4%, aromatics 13.5%, alkanes 10.6% and halogenated VOC (x-VOC) 5.0%. More aromatics and x-VOC were emitted from wood burning compared with straw burning. Field burning emitted more o-VOC due to more air being supplied during the burning test compared with stove burning. Further examination of the detailed VOC species showed the most abundant VOC species from biomass burning were o-VOC, C2-C3 alkenes and C6-C7 aromatics. The ozone formation potential (OFP) of VOCs from straw burning was in the range of 13.92-33.24 g/kg, which was much higher than that of wood burning (4.30 g/kg). Alkenes and o-VOC were the largest contributors to OFP of VOCs from biomass burning. The top five contributors of OFP were ethene, n-hexanal, propylene, acetaldehyde and methyl vinyl ketone, the sum of which accounted for 77% of total OFP. The ratio of ethylbenzene to m,p-xylenes from biomass burning was significantly higher than those from other VOC sources, and thus this could be seen as the fingerprint of biomass burning.