Estimating air pollutant emission factors from open burning of rice straw by the residual mass method

Air pollutant emission factors produced by open burning of rice straw were estimated using the residual mass method which incorporated ambient air-quality and meteorological data of measured stations. The residual mass method regarded the residual mass of air pollutants as emissions caused by the open burning of rice straw. Lasting from November 27–28, 2002, the selected episode resulted in the most serious air pollution in the recent decade in terms of open burning of rice straw, significantly degrading air quality in central-south Taiwan. Emission factors from open burning of rice straw, as modeled by the residual mass method, were 30.3 ± 1.45, 5.14 ± 0.13, 3.44 ± 0.09, 6.28 ± 0.34, and 0.058 ± 0.003 g kg−1 for CO, NMHCs, NOx, PM10 and SO2, respectively. The maximum daily emissions of CO and PM10 were 1000 kg km−2 and located at central-south Taiwan. Additionally, emissions of CO and PM10 in EPS were 7.67 and 9.33 times higher than MON during the rice straw burning episode. The spatial emission of EPS and MON were also presented with the residual mass method. Comparing our results with those of other studies revealed that calculated emission factors in this study were in an acceptable range.