秸秆露天焚烧典型大气污染物排放因子

利用烟气污染物稀释采样系统，基于实际测试，针对玉米、小麦、花生和棉花4种农作物秸秆开展露天焚烧排放大气污染物采集和分析.利用修正燃烧效率区分燃烧状态，根据碳平衡法计算烟气中颗粒物和气态污染物排放因子.结果表明，4种秸秆露天焚烧CO、SO₂、NO_x和CH₄平均排放因子分别在7.39~92.4g/kg、0.11~0.89g/kg、0.72~3.86g/kg和0.2~5.45g/kg之间，PM_2.5平均排放因子在1.48~13.29g/kg之间.OC和EC的质量分别占PM_2.5全部质量的27.7%~54.3%和4.4%~17.1%，是PM_2.5的主要组成成分.污染物排放主要来自混合燃烧状态，焖烧状态排放污染物浓度相对较高.随着含水率升高，焖烧过程增强显著，CO、CH₄、PM_2.5和OC的排放因子升高，其中PM_2.5排放量增高主要是由OC排放占比升高导致.

Emission factors of typical air pollutants from open burning of crop straws

Air pollutants emission from open burning of typical crop straws (including corn, wheat, peanut, and cotton) were characterized by using the flue gas pollutants dilution sampling system. The parameter of modified combustion efficiency (MCE) was applied to distinguish different combustion states. The carbon-balance methodology was adopted to calculate emission factors of particulate and gaseous air pollutants of flue gas from open burning. The results showed that the average emission factors of CO, SO₂, NO_x and CH₄ from the open burning of four crop straws were 7.39~92.4g/kg, 0.11~0.89g/kg, 0.72~3.86g/kg and 0.2~5.45g/kg, respectively. The average emission factor of PM_2.5 was 1.48~13.29g/kg. As the main component of PM_2.5, the mass ratio of organic carbon (OC) and elemental carbon (EC) accounted for 27.7%~54.3% and 4.4%~17.1% of the total mass of PM_2.5, respectively. Air pollutants mainly came from the mixed combustion state. The concentration of pollutants during the smoldering combustion state was relatively higher. With the increasing of moisture content, the duration of smoldering combustion state was prolonged significantly, which caused the emission factors of CO, CH₄, PM_2.5 and OC increased. The higher proportion of OC component was the main reason of increased PM_2.5 emission.