Self-sensitized photochlorination of benzo[a]pyrene in saline water under simulated solar light irradiation

Chlorinated organic compounds are ubiquitously detected in saline waters. The photochlorination of is one possible source, and chlorine radicals originating from other photosensitive substances have been reported to be responsible for chlorination previous reports. In this study, benzo[a]pyrene (BaP) 10% acetonitrile/NaCl aqueous solution was initiated by self-sensitization BaP, while were not involved the reaction. After 45 min photoreaction four seawater samples, chlorinated product (6-ClBaP) accounted 10–17% fraction transformed which higher than that previously reported. influences Cl−, pH, humic acid, electron donors, particulate matter on formation chlorobenzo[a]pyrene systematically investigated. A self-sensitized reaction mechanism proposed as follow: photoexited BaP activated singlet state then triplet through inter-system crossing. Then excited oxygen formed [3BaP*-3O2] or [BaP-1O2] complex, further reacted with Cl− produce 6-ClBaP.