Emission factors of selected air pollutants from rice straw open burning in the Mekong Delta of Vietnam

Abstract

This study was conducted to determine the emission factors (EF) of air pollutants from rice straw open burning (RSOB) in the Mekong Delta of Vietnam. The carbon balance method and emission ratio were applied to determine the EF from field experiments for particulate matter (PM including TSP, PM10, and PM2.5), PM-bound PAHs, VOCs, CO2, NO2, and SO2. The EFs (g.kg−1) of PM and gaseous pollutants were 12.1 ± 0.3 for PM2.5, 13.6 ± 2.6 for PM10, and 15.5 ± 3.5 for TSP, 1247 ± 190 for CO2, 1.4 ± 0.3 for SO2, and 1.3 ± 0.3 for NO2. The EFs (mg.kg−1) of the 16 particle-bound PAHs were 12.8 ± 2.5 for PM10, 12.5 ± 2.8 for TSP, in which, the EFs (mg.kg−1) of carcinogenic PAHs were 4.1 ± 0.9 for TSP and 4.3 ± 0.8 for PM10. EFVOCs was 10.7 mg kg−1, in which, the EFBTEX (mg.kg−1) was the dominant contributor to the EF of the total VOCs with 7.4 ± 2.7 mg kg−1 (69%). Given the EFs obtained in this study, the estimated total emission from RSOB in the Mekong Delta of Vietnam in 2019 was 79.8 Gg for PM2.5, 90 Gg for PM10, 102.6 Gg for TSP, 70.8 Mg for VOCs, 82 Mg for TSP-bound PAHs, 85 Mg for PM10-bound PAHs, 8233.8 Gg for CO2, 9.1 Gg for SO2 and 8.7 Gg for NO2. These EFs could be used for the emission inventory of air pollutants from RSOB national and regional scales.