Journal of Hazardous Materials B95 (2002) 175–184 Photodegradation of 1-nitropyrene in solution and in the adsorbed state Alexander Muck a , Pavel Kubát b , Anabela Oliveira c , Luis Filipe Vieira Ferreira c , Josef Cvaˇ cka d , Svatopluk Civiš b,∗ , Zdenˇ ek Zelinger b , Jiˇ r´ ı Barek a , Jiˇ r´ ı Zima a a UNESCO Laboratory of Environmental Electrochemistry, Department of Analytical Chemistry, Charles University, 128 43 Praha 2, Czech Republic b J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, 182 23 Praha 8, Czech Republic c Centro de Qu´ ımica-F´ ısica Molecular, Instituto Superior Técnico, Universidade Técnica de Lisboa., Complexo Interdisciplinar, Av. Rovisco Pais 1049-001, Lisboa, Portugal d Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo namesti 2, 166 10 Prague 6, Czech Republic Received 15 January 2002; received in revised form 17 April 2002; accepted 3 May 2002 Abstract The photodegradation of the 1-nitropyrene (NPy) has been studied using conventional (Xe and medium pressure Hg lamps) and laser sources (XeCl excimer and Nd-YAG UV). Low energy monochromatic light sources were used to study the early stages of degradation (up to 50% con- version). The medium pressure Hg lamp was used for longer periods of irradiation (up to 6 h) and for greater degradation of NPy. The results of our work confirm that degradation occurs by radical mechanism. Aromatic hydroxymethyl, methoxy, hydroxy and nitroso derivatives of pyrene (Py) are created by low energy UV irradiation. After a massive UV irradiation, the Py aromatic system is destroyed and more polar low-molecular compounds are generated. The photochemical method described in this paper, based on irradiation by UV lamp, is therefore, suitable for degradation of fused benzene ring(s) and thus should also be effective for degradation of other nitrated polycyclic aromatic compounds. © 2002 Elsevier Science B.V. All rights reserved. Keywords: 1-Nitropyrene; Photolysis; HPLC; Mass spectroscopy ∗ Corresponding author. Tel.: +420-2-66-053085; fax: +420-2-8591766. E-mail address: civis@jh-inst.cas.cz (S. Civiš). 0304-3894/02/$ – see front matter © 2002 Elsevier Science B.V. All rights reserved. PII:S0304-3894(02)00120-6