Insights into the Formation Mechanism of Reactive Oxygen Species in the Interface Reaction of SO on Hematite.

The interplay between sulfur and iron holds significant importance in their atmospheric cycle, yet a complete understanding of their coupling mechanism remains elusive. This investigation delves comprehensively into the evolution of reactive oxygen species (ROS) during the interfacial reactions involving sulfur dioxide (SO) and iron oxides under varying relative humidity conditions. Notably, the direct activation of water by iron oxide was observed to generate a surface hydroxyl radical (•OH).

An Alternative Calibration Method for Measuring NO with an Iodide-Chemical Ionization Mass Spectrometer and Influencing Factors.

In this work, we developed an alternative calibration method for measuring NO with an iodide adduct mass spectrometer (I-CIMS). In this calibration method, NO is heated and then quantified based on the decrease in the amount of NO due to its reaction with the pyrolysis product (NO). This alternative calibration method was compared with the commonly used method utilizing NO analyzers equipped with a photolytic converter, which gauge NO reduction as a result of its reaction with O to quantify NO.

Nonlinear effect of NO concentration decrease on secondary aerosol formation in the Beijing-Tianjin-Hebei region: Evidence from smog chamber experiments and field observations.

During the COVID-19 lockdown in the Beijing-Tianjin-Hebei (BTH) region in China, large decrease in nitrogen oxides (NO) emissions, especially in the transportation sector, could not avoid the occurrence of heavy PM pollution where nitrate dominated the PM mass increase. To experimentally reveal the effect of NO control on the formation of PM secondary components (nitrate in particular), photochemical simulation experiments of mixed volatile organic compounds (VOCs) under various NO concentrations with smog chamber were performed. The proportions of gaseous precursors in the control experiment were comparable to ambient conditions typically observed in the BTH region.

Photocatalytic Oxidation of NO on TiO : Evidence of a New Source of N O.

N O is an important intermediate in the atmospheric nitrogen cycle. Using a flow tube reactor, N O was found to be released from the TiO surface during the photocatalytic oxidation of NO , revealing a previously unreported source of N O . The rate of N O release from TiO was dependent on the initial NO concentration, relative humidity, O /N ratio, and irradiation intensity.

Dramatic decrease of secondary organic aerosol formation potential in Beijing: Important contribution from reduction of coal combustion emission.

Secondary organic aerosol (SOA) formation originating from the emission of anthropogenic volatile organic compounds (VOCs) makes a significant contribution to fine particulate matter (PM) pollution in urban areas. Investigation on the SOA formation potential (SOAFP) can help us understand the contribution of different sources to SOA formation. To characterize the SOAFP of ambient air from anthropogenic VOCs in the urban area of Beijing, field observation was implemented using a twin oxidation flow reactor (Twin-OFRs) system in the winters of 2016 and 2017.