*THI HIEN TO1, Anh Ngan Tran2, Hoang Minh Tran3, Thanh Nhon Nguyen Thi4, Thien Chi Nguyen Doan5, Sy Phu Nguyen Ly6, Cong Thanh Tran7
(1.To Thi Hien, Faculty of Environment, University of Science Vietnam National University Ho Chi Minh City, Vietnam, 2.Tran Anh Ngan, Faculty of Environment, University of Science Vietnam National University Ho Chi Minh City, Vietnam, 3.Tran Hoang Minh, Faculty of Environment, University of Science Vietnam National University Ho Chi Minh City, Vietnam, 4.Nguyen Thi Thanh Nhon, Faculty of Environment, University of Science Vietnam National University Ho Chi Minh City, Vietnam, 5.Nguyen Doan Thien Chi, Faculty of Environment, University of Science Vietnam National University Ho Chi Minh City, Vietnam, 6.Nguyen Ly Sy Phu, Faculty of Environment, University of Science Vietnam National University Ho Chi Minh City, Vietnam, 7.Tran Cong Thanh, Faculty of Environment, University of Science Vietnam National University Ho Chi Minh City, Vietnam)
Keywords:Biomass Burning, Fine particulate matter, Organic Carbon, Elemental Carbon, Vietnam
Agricultural biomass burning has a significant impact on air quality, atmosphere, and climate. In Vietnam, burning rice straw after harvest is a typical agricultural biomass-burning activity. This study will present the current status of biomass burning from agricultural activities in Vietnam and a typical research result in determining fine particulate matter from straw burning activities in Tien Giang Province. The mass concentrations of PM1.0 and PM2.5 and organic carbon (OC) and elemental carbon (EC) in PM2.5 were measured during the burning of rice straw in a field of 20,000 m2 in Tien Giang province, Vietnam. PM1.0 and PM2.5 were measured using the AS-Lung sensors. PM2.5 samples were collected using an SKC sampler, and OC and EC in PM2.5 were analyzed using the NIOSH thermal-optical transmittance (TOT) standard method. The average PM concentrations during burning were 50.3 ± 80.6 µg/m3 (3.4 – 377.9 µg/m3) for PM1.0 and 111.7 ± 217.0 µg/m3 (10.6 – 2005.6 µg/m3) for PM2.5, which were about 3.5 times higher than before and after burning. The ratios of PM1/ PM2.5 were 0.4 ± 0.1 (0.1 – 0.8) in burning and 0.5 ± 0.1 (0.2 – 0.7) before and after burning. On the day of burning the rice straw, the concentration of OC (16.28 µg/m3) and EC (1.28 µg/m3) was higher 2 times and 1.3 times than days before burning, respectively. The OC/EC ratios ranged from 6.15 – 12.77 (average 8.90 ± 2.15), the highest OC/EC ratios also on the day of burning rice straw. Analysis of OC and EC fractions showed that OC1, OC3, OC4, and EC3, EC4 have a predominant concentration in the carbon fractions, which is typical for the emission of carbonaceous aerosol from the burning of rice straw.