中国亚热带地区2005～2014年秸秆露天燃烧排放污染物

摘要

The emission factors of CO, CO2, NOx, CxHyand PM2.5 in rice, wheat, beans, rape, maize and cotton were measured by indoor simulation experiment. In addition, the crop straw yield and the amount of field combustion were calculated, based on the statistical yearbook, in order to estimate total emissions of various types of pollutants from open burning of straw in eight provinces of subtropical China during 2005~2014, and temporal and spatial trends were analyzed. The results showed that the average emission factors of CO, CO2, NOx, CxHyand PM2.5 from combustion of crop straw were 159.55, 1234.96, 1.88, 31.27 and 7.62g/kg, respectively. The highest average emission factor of each pollutant was for cotton (172.40g/kg), beans (1348.77g/kg), rape (4.08g/kg), rice (66.78g/kg) and beans (10.15g/kg). The output of crop straw and the total amount of field combustion in subtropical areas of China were 1221.281Mt and 261.729Mt, respectively during the study period. Emissions of CO, CO2, NOx, CxHyand PM2.5 were 40890.56, 324104.01, 370.79, 14329.36 and 1835.94kt, respectively. The emissions of NOxand other pollutants from rice straw burning in the field accounted for more than 60% and 75% of the total emission in the study area. The emission contribution of wheat and cotton was less than 5% of the total emitted pollutants. There was also spatial variation in emission of different pollutants. The emission of pollutant exhibited a downward trend in Zhejiang, Fujian and Guizhou while rising trend was observed in Guangdong, Guangxi, Yunnan and Jiangxi.%通过室内模拟试验,测量中国亚热带地区水稻、小麦、豆类、油菜、玉米和棉花中CO、CO2、NOx、CxHy和PM2.5的排放因子,并基于统计年鉴计算出的研究区域农作物秸秆产量和露天燃烧量,对亚热带地区8个省分2005-2014年间秸秆露天燃烧各类污染物的排放总量进行估算,并分析其时空变化趋势.结果表明,农作物秸秆燃烧时 CO、CO2、NOx、CxHy 和 PM2.5的平均排放因子分别为159.55,1234.96,1.88,31.27,7.62g/kg.其中,各污染物平均排放因子最高的农作物依次是棉花(172.40g/kg)、豆类(1348.77g/kg)、油菜(4.08g/kg)、水稻(66.78g/kg)和豆类(10.15g/kg).2005-2014年,我国亚热带地区农作物秸秆产量和露天燃烧总量分别为1221.281Mt 和261.729Mt;CO、CO2、NOx、CxHy和PM2.5的排放量分别为40890.56,324104.01,370.79,1429.36,1835.94kt.其中,水稻秸秆燃烧所排放NOx占研究区域总排放量的60%左右,对其余污染物的贡献率均在75%以上;小麦和棉花对各类污染物的贡献程度均不足5%.此外,各污染物排放在时间和空间上的变化存在差异.浙江、福建和贵州污染物排放呈下降趋势,广东、广西、云南、湖南和江西呈上升趋势.