| Summary: | 碩士 === 雲林科技大學 === 環境與安全工程系碩士班 === 98 === Open burning of agricultural waste is a common means to cleaning land for farming, and biomass burning smoke is one of the major ambient air pollution in Taiwan. This study is aimed to characterize particle-sized characteristics as well as the compositions of particulate mass, carbon species ( OC vs. EC ), three anhydrosugars ( levoglucosan, mannosan, and galactosan ) and water soluble inorganic species derived from rice straw burning in chamber. The study discuss the particle-sized characteristics in three combustion conditions ( smoldering, flaming, and mixing ) under two different atmospheric humidity ( 60% RH vs. 80% RH ) from chamber burning. Moreover, the study monitor gaseous pollutants ( CO vs. CO2 ) immediately and attempt to estimate the emission factor.
The results shown that smoldering has the highest particulate concentration in three combustion conditions. The particle size distribution of rice straw burning was concentrated in PM2.5 ( about 65.1~83.7% in TSP ), and the coarse particle increased along of combustion conditions and relative humidity. When the relative humidity became higher, the coarse particle concentration and the total emission are increased. In addition, the levoglucosan constituent accounts for over 90% in three anhydrosugars from rice straw burning in chamber. The ratio of levoglucosan and mannosan ( levo/mann ) was approximately 40 ± 20, the deviation is caused from the burning temperture influence cellulose cracking level. The organic carbon ( OC ) was mainly carbon emissions composition ( OC account for more than 90%, EC accounted for 1.5~5.3% ), the results shown that rice straw burning is belong incomplete burning. The rice straw burning for water soluble inorganic species were dominated by K+, NH4+, Na+, SO42-, F-, Cl-. Moreover, the emission factor for PM was 1.50 g/kg in flaming burning, 5.13 g/kg in mixing burning, and 8.15 g/kg in smoldering burning.Other items like OC was 1.26 ~ 2.14 g/kg, EC was 0.03 ~ 0.06 g/kg for rice straw burning. CO2 was 820.7 g/kg in mixing burning ( Flaming 1578.2 g/kg, Smoldering 641.3 g/kg ). In the study, all the emission factor was only for dry-biomass fuel. The study is helpful to resolve the emission characteristic for rice straw burning, and estimate the total emission. That could be the basis for developing air pollutants control provision.
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