Correlation analysis of element contents between forest fuel and PM2.5 released by combustion of main tree species in Fujian Province
Exploring the element contents and their correlation between forest fuel and fine particulate matter(PM2.5)emitted during combustion and revealing the migration trajectory of each element during forest fire provide an important basis for understanding the impacts of forest fire on environmental chemical element content and eco-system material cycle.The branches,leaves and bark of four tree species(Pinus massoniana,Cunninghamia lan-ceolata,Eucalyptus robusta and Cinnamomum camphora)were burnt under smoldering and flaming states using self-designed combustion simulation device to measure the contents of five major elements(Mg,Al,P,K,Ca)and seven trace elements(Na,Cr,Mn,Fe,Ni,Cu,Zn).We analyzed the differences of element contents in PM2.5 emitted between different burning states,and the correlation between the element contents of fuels and the emission factors of each element in emitted PM2.5.The results showed that the contents of Mg,K,Ca and Zn in for-est fuel were higher.The element contents in conifers were generally higher than those in broadleaved species,and the element contents in different organs of same tree species were significantly different.The emission factors of Mg,K,Ca and Zn in PM2.5 released during combustion were highest,followed by Cu and Cr,with a pattern of higher for the major elements than for the trace elements.Combustion states influenced emission factors of elements,gener-ally showing that flaming was greater than smoldering.Under different combustion states,the ratio of Cu content in PM2.5 released during combustion of each organ to its own element content was the highest,and the ratios of other elements ranged from 0 to 0.09％.The correlations of element contents between forest fuels and PM2.5 were relatively high(0.700-0.999).In conclusion,there were differences in emissions of flue gas and PM2.5 released by the com-bustion among different tree organs,and there was a strong correlation between fuel itself and PM2.5 released by fuel combustion.
万方数据
