报告人： Chak K. Chan
报告时间：2025年7月2日（星期三）15:00
报告地点：绿色环境楼200号会议室
邀请人： 赵岳、李晨曦
报告摘要：
Incense burning, a common ritual in Asian cultures, especially in coastal cities, emits significant particles in temples and households. Particulate aromatic carbonyls, key components of incense burning aerosols, contain photosensitizers that can produce oxidants for in-particle oxidation such as sulfate formation from SO2. Using single particle aerosol mass spectrometry (SPAMS), we observed that sulfate formation in incense burning particles does not solely depend on traditional gas-phase reactions. Instead, it is significantly influenced by photosensitization, which is dependent on various environmental conditions such as relative humidity and UV light exposure. Furthermore, internally mixed incense burning and sea-salt particles are often found in coastal regions. We observed enhanced sulfate production in laboratory-generated droplets containing incense smoke (IS) extracts and sodium chloride (IS−NaCl) over pure NaCl droplets under irradiation, attributable to photosensitization induced by IS constituents. Photosensitizers like vanillin (VL) and syringaldehyde (SyrAld) found in IS samples can markedly accelerate SO2 oxidation. Moreover, the excited triplet state of the photosensitizer might interact with chloride ions to generate reactive chlorine species. Such synergistic effects between chlorine chemistry and photosensitization could further enhance sulfate formation. Additionally, the aging of IS particles further promoted sulfate production. This is likely due to increased secondary oxidant production driven by a higher proportion of nitrogen-containing species relative to fresh IS particles. Our studies highlight the substantial impact of photosensitized oxidation processes in sulfate production, particularly in areas impacted by incense burning, offering new insights into atmospheric sulfate formation mechanisms. The similarity between incense burning and biomass burning particle mass spectra suggests that biomass burning may also trigger sulfate formation. Using sulfate formation as a tool, we demonstrate that photosensitization of incense burning aerosol can enhance the atmospheric oxidative capacity and promote secondary aerosol formation.
报告人简介：
Chak Chan教授现任阿卜杜拉国王科技大学（KAUST）能源与环境女王调教 院长。他分别在美国德克萨斯大学奥斯汀分校和加州理工女王调教 获得化学工程学士和博士学位，随后加入香港科技大学（HKUST）化学工程系工作，先后任讲师、助理教授、教授、副系主任。2009年，担任HKUST环境学部创系主任。2015年12月，Chak Chan教授加入香港城市大学，担任能源与环境女王调教 第二任院长。2023年5月，他加入KAUST。Chak Chan教授是国际著名的大气化学家，研究聚焦大气物理化学，尤其是空气中颗粒物的化学特性。迄今发表250余篇SCI论文（其中一半以上为通讯作者），SCOPUS引用超过16000次，H指数为61；Google Scholar引用逾20000次，H指数达66。