Uptake and Surface Reactions on Soot

Soot is emitted by incomplete combustion of fossil fuel and biomass. It is also caUed black carbon since it strongly absorbs the solar and terrestrial radiation in aU of ultraviolet, visible and infrared regions, and attention is paid as one of the radiatively active species from the cUmate change point of view. As reactions oti 

It has been suggested that the uptake and decomposition of O3 on soot particles contribute to the loss of O3 due to the emission from aircraft in the lower stratosphere and upper troposphere (Lary et al. 1997) and nighttime loss of O3 in the urban atmosphere (Berkowitz et al. 2001), and many measurement have been made (Sander et al. 2011). 

The uptake process of O3 by the new soot causes very large initial loss of O3, but the uptake rate decreases drastically as the reaction proceeds or for the pre-treated 

The uptake and reaction of NO2 on soot is very important as a process to release nitrous acid (HONO) into the gas phase. The formation of HONO by the heterogeneous surface reaction and its enhancement by light irradiation has been found for the first time by Akimoto et al. (1987) relevant to the unknown radical source in a smog chamber (see column on p.278). The uptake of NO2 and photocatalytic reaction on soot has been interested in as a model reaction of such heterogeneous process to elucidate the characteristics of HONO formation in the atmosphere. 

In the polluted atmosphere, HONO has been measured at far higher cmicentra-tions than expected from the production rate by the homogeneous gas phase reaction, OH + NO + M HONO+M (Sect. 5.2.4), and the discussimis oti the contribution other than the homogeneous reaction have been made in model analysis studies (Gongalves et al. 2012 Elshorbany et al. 2012). 

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