Photochemical degradation of nitrated PAHs in snow

Abstract Nitrated polycyclic aromatic hydrocarbons (NPAHs) are derived from PAHs, which are ubiquitous in the aqueous and atmospheric environments, and whose mutagenicity and carcinogenicity are much higher than that of PAHs. Therefore, their environmental transformation has attracted a lot of attention. In the present study, direct and indirect UV photodegradation kinetics of two NPAHs (1-nitropyrene and 1,8-dinitropyrene) in snow were investigated. It was found that the kinetics followed the pseudo-first-order kinetics with the photochemical degradation rate 0.3773 h −1 for 48.98 nM 1-NP and 0.3653 h −1 for 41.00 nM 1,8-DNP. Photosensitizers (hydrogen peroxide and nitrate) promoted the photodegradation of NPAHs. Considering the lower temperature and less microorganisms in snow environment, the photodegradation can be a key factor in determining the fate of NPAHs in sunlit surface snow. To the best of our knowledge, this is the first report on the photodegradation of NPAHs in snow.