Li Qing, Zhang Kun, Li Rui, Yang Liumei, Yi Yanan, Liu Zhiqiang, Zhang Xiaojuan, Feng Jialiang, Wang Qiongqiong, Wang Wu, Huang Ling, Wang Yangjun, Wang Shunyao, Chen Hui, Chan Andy, Latif Mohd Talib, Ooi Maggie Chel Gee, Manomaiphiboon Kasemsan, Yu Jianzhen, Li Li
School of Environmental and Chemical Engineering, Shanghai University, Shanghai, China; Key Laboratory of Organic Compound Pollution Control Engineering (MOE), Shanghai University, Shanghai, China.
School of Environmental and Chemical Engineering, Shanghai University, Shanghai, China; Key Laboratory of Organic Compound Pollution Control Engineering (MOE), Shanghai University, Shanghai, China; Jiangsu Changhuan Environment Technology Co., Ltd., Changzhou, Jiangsu, China.
Sci Total Environ. 2023 May 10;872:162071. doi: 10.1016/j.scitotenv.2023.162071. Epub 2023 Feb 11.
Biomass burning (BB) has significant impacts on air quality and climate change, especially during harvest seasons. In previous studies, levoglucosan was frequently used for the calculation of BB contribution to PM, however, the degradation of levoglucosan (Lev) could lead to large uncertainties. To quantify the influence of the degradation of Lev on the contribution of BB to PM, PM-bound biomass burning-derived markers were measured in Changzhou from November 2020 to March 2021 using the thermal desorption aerosol gas chromatography-mass spectrometry (TAG-GC/MS) system. Temporal variations of three anhydro-sugar BB tracers (e.g., levoglucosan, mannosan (Man), and galactosan (Gal)) were obtained. During the sampling period, the degradation level of air mass (x) was 0.13, indicating that 87 % of levoglucosan had degraded before sampling in Changzhou. Without considering the degradation of levoglucosan in the atmosphere, the contribution of BB to OC were 7.8 %, 10.2 %, and 9.3 % in the clean period, BB period, and whole period, respectively, which were 2.4-2.6 times lower than those (20.8 %-25.9 %) considered levoglucosan degradation. This illustrated that the relative contribution of BB to OC could be underestimated (14.9 %) without considering degradation of levoglucosan. Compared to the traditional method (i.e., only using K as BB tracer), organic tracers (Lev, Man, Gal) were put into the Positive Matrix Factorization (PMF) model in this study. With the addition of BB organic tracers and replaced K with K (the water-soluble potassium produced by biomass burning), the overall contribution of BB to PM was enhanced by 3.2 % after accounting for levoglucosan degradation based on the PMF analysis. This study provides useful information to better understand the effect of biomass burning on the air quality in the Yangtze River Delta region.
生物质燃烧（BB）对空气质量和气候变化有重大影响，尤其是在收获季节。在以往的研究中，左旋葡聚糖经常被用于计算生物质燃烧对颗粒物的贡献，然而，左旋葡聚糖（Lev）的降解可能导致很大的不确定性。为了量化Lev降解对生物质燃烧对颗粒物贡献的影响，2020年11月至2021年3月期间在常州使用热脱附气溶胶气相色谱-质谱联用（TAG-GC/MS）系统测量了与颗粒物结合的生物质燃烧衍生标志物。获得了三种脱水糖生物质燃烧示踪剂（如左旋葡聚糖、甘露聚糖（Man）和半乳聚糖（Gal））的时间变化。在采样期间，气团的降解水平（x）为0.13，这表明在常州采样前约87%的左旋葡聚糖已经降解。在不考虑大气中左旋葡聚糖降解的情况下，生物质燃烧对有机碳（OC）的贡献在清洁期、生物质燃烧期和整个时期分别为7.8%、10.2%和9.3%，比考虑左旋葡聚糖降解时（20.8%-25.9%）低2.4-2.6倍。这表明，不考虑左旋葡聚糖降解时，生物质燃烧对有机碳的相对贡献可能被低估（约14.9%）。与传统方法（即仅使用钾作为生物质燃烧示踪剂）相比，本研究将有机示踪剂（Lev、Man、Gal）纳入正矩阵因子分解（PMF）模型。基于PMF分析，在考虑左旋葡聚糖降解后，加入生物质燃烧有机示踪剂并用K（生物质燃烧产生的水溶性钾）替代钾后，生物质燃烧对颗粒物的总体贡献提高了3.2%。本研究为更好地理解生物质燃烧对长江三角洲地区空气质量的影响提供了有用信息。
