報(bào)告人：  Chak K. Chan

報(bào)告時(shí)間：2025年7月2日（星期三）15:00

報(bào)告地點(diǎn)：綠色環(huán)境樓200號(hào)會(huì)議室

邀請(qǐng)人：  趙岳、李晨曦

報(bào)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.

報(bào)告人簡(jiǎn)介：

Chak Chan教授現(xiàn)任阿卜杜拉國(guó)王科技大學(xué)（KAUST）能源與環(huán)境學(xué)院院長(zhǎng)。他分別在美國(guó)德克薩斯大學(xué)奧斯汀分校和加州理工學(xué)院獲得化學(xué)工程學(xué)士和博士學(xué)位，隨后加入香港科技大學(xué)（HKUST）化學(xué)工程系工作，先后任講師、助理教授、教授、副系主任。2009年，擔(dān)任HKUST環(huán)境學(xué)部創(chuàng)系主任。2015年12月，Chak Chan教授加入香港城市大學(xué)，擔(dān)任能源與環(huán)境學(xué)院第二任院長(zhǎng)。2023年5月，他加入KAUST。Chak Chan教授是國(guó)際著名的大氣化學(xué)家，研究聚焦大氣物理化學(xué)，尤其是空氣中顆粒物的化學(xué)特性。迄今發(fā)表250余篇SCI論文（其中一半以上為通訊作者），SCOPUS引用超過(guò)16000次，H指數(shù)為61；Google Scholar引用逾20000次，H指數(shù)達(dá)66。