The photo-induced degradation of naphthalene, 1,4-naphtho-quinone, 1-naphthol and 1-NO 2 naphthalene, adsorbed on silica gel, and with the addition of nitrogenous air pollutants e.g. NO 2 - (as KNO 2 ) was investigated. Results indicate that compounds adsorbed onto a solid carrier are degraded when irradiated with UV light (??> 290 nm) in the presence of nitrites. The key species initiating the naphthalene degradation is the OH-radical which is generated through the photolysis of NO 2- . Reaction products identified were 2-formyl-cinnamaldehyde, 1,4-naphthoquinone, nitronaphthol, o-phthaldialdehyde, phthalide and nitronaphthalene. A mass balance between 40 - 50% was achieved. Under the same irradiation conditions, 1-NO 2 naphthalene is mainly degraded by direct photolysis while degradation of 1-naphthol and 1,4-naphthoquinone proceeds via the reaction with OH-radicals. Identified products were hydroxy- nitro- nitroso-and quinones compounds. |
