title: Heterogeneous Photochemical Conversion of NO2 to HONO on the Humic Acid Surface under Simulated Sunlight.
abstract: The poor understanding of HONO sources in the daytime highlights the importance of the heterogeneous photochemical reaction of NO2 with aerosol or soil surfaces. The conversion of NO2 to HONO on humic acid (HA) under simulated sunlight was investigated using a flow tube reactor at ambient pressure. The uptake coefficient (γ) of NO2 linearly increased with irradiation intensity and HA mass in the range of 0-2.0 μg/cm(2), while it decreased with the NO2 concentration. The HONO yield was found to be independent of irradiation intensity, HA mass, and NO2 concentration. The temperature (278-308 K) had little influence on both γ and HONO yield. Additionally, γ increased continuously with relative humidity (RH, 7-70%), and a maximum HONO yield was observed at 40% RH. The heterogeneous photochemical reaction of NO2 with HA was explained by the Langmuir-Hinshelwood mechanism.
authors.affiliation: School of Metallurgy, Northeastern University , Shenyang, Liaoning 110819, People's Republic of China.
authors.forename: Chong
authors.initials: C
authors.lastname: Han
authors.affiliation: School of Metallurgy, Northeastern University , Shenyang, Liaoning 110819, People's Republic of China.
authors.forename: Wangjin
authors.initials: W
authors.lastname: Yang
authors.affiliation: School of Metallurgy, Northeastern University , Shenyang, Liaoning 110819, People's Republic of China.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Wu
authors.affiliation: School of Metallurgy, Northeastern University , Shenyang, Liaoning 110819, People's Republic of China.
authors.forename: He
authors.initials: H
authors.lastname: Yang
authors.affiliation: School of Metallurgy, Northeastern University , Shenyang, Liaoning 110819, People's Republic of China.
authors.forename: Xiangxin
authors.initials: X
authors.lastname: Xue
mesh_terms: D000336:Aerosols; D006812:Humic Substances; D009608:Nitrous Acid; D012987:Soil; D013472:Sunlight
chemical_list: D000336:Aerosols; D006812:Humic Substances; D012987:Soil; D009608:Nitrous Acid