生物质燃烧标识物的表征与环境过程研究

Biomass burning is an important source of atmospheric aerosol that is influencing air quality, visibility and the Earth’s albedo by scattering and absorbing solar radiation. Biomass combustion emissions are also known to be one of the major contributors to haze pollution in China. Spatial-temporal distribution and contributions of biomass burning emissions to particle pollution are often estimated by biomass burning molecular markers. In this project, we plan to investigate the emissions from burning of agricultural crop straws that are often used in China (including rice, wheat and corn straws) in the combustion chamber. The emission profiles and the ratios between molecular markers and organic carbon (OC) will be studied for different straws. We will also take PM2.5 samples simultaneously at Guanzhong region, China including one urban site and one background site in summer and winter. The seasonal variation of biomass burning emissions and contributions of different crop straw to OC and PM2.5 will be studied. In combination with the datasets from field measurements and combustion chamber studies, relationship between atmospheric oxidation capability, aerosol acidity, temperature, relative humidity, moisture and biomass burning markers will be investigated to discuss the stability and aging mechanism of the molecular makers from biomass burning emissions. The results obtained will provide useful dataset to better understand the biomass burning emissions in China and scientific knowledge for air pollution control.

生物质燃烧排放是大气气溶胶的重要来源之一，可通过散射和吸收太阳辐射影响地球反照率和降低能见度，是造成灰霾污染的主要因素之一。为了认识生物质燃烧的时空分布特征，定量计算生物质燃烧的贡献，需要通过生物质燃烧标识物来进行研究。本课题拟对我国主要农作物秸秆样品进行燃烧模拟箱实验，获得生物质燃烧源样品的全组分谱特征值以及小麦、水稻和玉米燃烧排放的标识物与有机碳的比值；并于冬季和夏季在关中地区城市点和背景点展开PM2.5同步采样，认识关中地区生物质燃烧排放的季节变化规律，获得不同农作物秸秆燃烧对有机碳和PM2.5的贡献。结合后向轨迹和火点图，建立大气氧化性、气溶胶酸性、温度、相对湿度、含水量等与生物质燃烧有机标识物的关系，探讨生物质燃烧标识物的老化机制，评价各个标识物的适用条件与范围。为揭示我国生物质燃烧的排放特征提供数据基础，为政府进行污染控制与减排提供科学依据。

生物质燃烧排放是大气气溶胶的重要来源之一，可通过散射和吸收太阳辐射影响地球反照率和降低能见度，是造成灰霾污染的主要因素之一。为了认识生物质燃烧的时空分布特征，定量计算生物质燃烧的贡献，需要通过生物质燃烧标识物来研究生物质燃烧的分布特征、变化规律、对大气污染的贡献等。为揭示我国生物质燃烧的排放特征提供数据基础，为政府进行污染控制与减排提供科学依据。.本课题通过对我国现阶段主要农作物秸秆（小麦、水稻和玉米秸秆）样品进行燃烧模拟箱实验获得燃烧排放细颗粒物全组分谱特征，为我国生物质燃烧排放状况的调查研究，以及大气污染的治理提供了重要的数据支持；通过在我国典型农业区关中平原城市点和背景点的外场观测研究，获得了PM2.5中与生物质燃烧来源相关的化学组分的时空分布特征；通过对有机气溶胶质谱进行正矩阵因子解析，区分不同来源的有机物组分，获得关中平原生物质燃烧源的贡献。.目前已发表的成果及数据对我国各省市生物质燃烧的排放量进行了估算；对关中平原大气细颗粒物的污染特征和来源进行了分析。通过研究认为生物质燃烧排放仍是目前关中平原大气污染控制应重点关注的问题之一。