title: Heterogeneous oxidation of SO2 by O3-aged black carbon and its dithiothreitol oxidative potential.
abstract: Ozone (O3) is an important atmospheric oxidant. Black carbon (BC) particles released into the atmosphere undergo an aging process via O3 oxidation. O3-aged BC particles may change their uptake ability toward trace reducing gases such as SO2 in the atmosphere, leading to different environmental and health effects. In this paper, the heterogeneous reaction process between O3-aged BC and SO2 was explored via in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Combined with ion chromatography (IC), DRIFTS was used to qualitatively and quantitatively analyze the sulfate product. The results showed that O3-aged BC had stronger SO2 oxidation ability than fresh BC, and the reactive species/sites generated on the surface had an important role in the oxidation of SO2. Relative humidity or 254nm UV (ultraviolet) light illumination enhanced the oxidation uptake of SO2 on O3-aged BC. The oxidation potentials of the BC particles were detected via dithiothreitol (DTT) assay. The DTT activity over BC was decreased in the process of SO2 reduction, with the consumption of oxidative active sites.
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China. Electronic address: vera_xww@163.com.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Xu
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; POTEN Environment Group Co., Ltd., Beijing 100082, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China. Electronic address: shangjing@pku.edu.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Shang
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Feng
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
authors.forename: Tong
authors.initials: T
authors.lastname: Zhu
mesh_terms: D000393:Air Pollutants / Q000737:chemistry*; D002852:Chromatography, Ion Exchange; D004229:Dithiothreitol / Q000737:chemistry; D010083:Oxidants, Photochemical / Q000737:chemistry*; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D053260:Soot / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013458:Sulfur Dioxide / Q000737:chemistry*
chemical_list: D000393:Air Pollutants; D010083:Oxidants, Photochemical; D053260:Soot; D013458:Sulfur Dioxide; D010126:Ozone; D004229:Dithiothreitol
keywords: Black carbon; Dithiothreitol assay; Heterogeneous reaction; Oxidative potential; Ozone; SO(2)