Direct photolysis of nitroaromatic compounds in aqueous solutions

Article type: Research Article

Authors: CHEN, Bing | YANG, Chun | GOH, Ngoh Khang

Affiliations: Division of Chemistry, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616

Note: [] Corresponding author. E-mail: [email protected]

Abstract: The direct photolysis of nitrobenzene and nitrophenols in aqueous solutions irradiated by polychromatic light were investigated. Several aromatic intermediates were identified as three nitrophenol isomers, nitrohydroquinone, nitrosobenzene, nitrocatechol, catechol and phenol. Nitrite and nitrate ions were also detected in the irradiated solution indicating direct photolysis of nitrobenzene or nitrophenols. The degradation of nitrobenzene and nitrophenols and the formation of three nitrophenol isomers were observed to follow zero-order kinetics. The quantum yields for nitrobenzene and nitrophenols removal are about 10^{-3} and 10^{-3}–10^{-4} respectively. The mechanism for nitrobenzene degradation was suggested to follow mainly nitro-nitrite intramolecular arrangement.

Keywords: photodegradation, photolysis, nitrobenzene, nitrophenols

Journal: Journal of Environmental Sciences, vol. 17, no. 4, pp. 598-604, 2005