Analysis of Black Carbon on Filters by Image-Based Reflectance - Filter Data

Black carbon (BC) is an important contributor to global particulate matter emissions. BC is associated with adverse health effects, and an important short-lived climate pollutant. Here, we describe a low cost method of analysis that utilizes images of Teflon filters taken with a digital camera to estimate BC content on filters. This method is compared with existing optical methods for analyzing BC (Smokestain Reflectance and Hybrid Integrating Plate and Sphere System) as well as the standard chemical analysis method for determining elemental carbon (Thermal-Optical Reflectance). In comparisons of aerosol generated under controlled conditions (using an inverted diffusion flame burner to cover a range of mass loading and reflectance levels) (N=12) and in field samples collected from residential solid fuel combustion in China and India (N=50), the image-based method was found to correlate well (mean RMSE <10% for all comparisons) with existing methods. A correlational analysis of field samples between the optical methods and Fourier-transform infrared spectroscopy indicated that the same functional groups were predominantly responsible for light attenuation in each optical method. This method offers reduced equipment cost, rapid analysis time, and is available at no cost, which may facilitate more measurement of BC where PM2.5 mass concentrations are already measured, especially in low income countries or other sampling efforts with limited resources. This dataset contains the values for each type of analysis performed for the tested filters.

黑碳（Black Carbon, BC）是全球颗粒物排放的重要贡献组分。黑碳与不良健康效应相关，同时也是一类重要的短期气候污染物。本研究介绍了一种基于数码相机拍摄特氟龙（Teflon）滤膜图像以估算滤膜上黑碳含量的低成本分析方法，并将该方法与现有黑碳光学分析方法——烟渍反射法（Smokestain Reflectance）与混合积分板球系统（Hybrid Integrating Plate and Sphere System）——以及测定元素碳的标准化学分析方法热光反射法（Thermal-Optical Reflectance）进行了对比。在针对受控条件下生成的气溶胶（采用倒置扩散火焰燃烧器覆盖一系列质量负载与反射率水平，样本量N=12）以及在中国与印度民用固体燃料燃烧场景采集的现场样本（样本量N=50）的对比中，该图像分析法与现有方法均表现出良好的相关性，所有对比的平均均方根误差（RMSE）均小于10%。对现场样本开展的光学方法与傅里叶变换红外光谱（Fourier-transform infrared spectroscopy）相关性分析表明，两类光学方法的光衰减主要由相同的官能团贡献。该方法具备设备成本低廉、分析速度快且可免费使用的优势，可助力在已开展PM2.5质量浓度监测的场景中拓展黑碳检测工作，尤其适用于低收入国家或资源有限的采样项目。本数据集包含针对各受试滤膜开展各类分析所得的全部结果数据。