Photochemical reaction of 2-chlorobiphenyl with N(III) (H2ONO~+/HONO/NO2~-) in acidic environment studied by using co-linear laser flash photolysis

摘要

Photo-induced transformation in the presence of N(III) is an important pathway for pollutants conversion in atmospheric condensed phase. In this study, the photochemical reaction between 2-chlorobiphenyl and N(III) was investigated in acidic environment by using co-linear laser flash photolysis technique. The photo-induced conversion of 2-PCB is initiated from its rapid oxidation by ~·OH, a primary product from the photolysis of N(III). The second-order rate constant for the reaction between 2-PCB and ~·OH was determined to be (8.9± 1.2) x 10~9 M~(-1) s~(-1). HONO and NO2~- were found to be more important than H2ONO~+ with respect to the photochemical transformation of pollutants in atmospheric hydrometeors. The complicated photochemical conversion pathways and their significance in the atmosphere were discussed as well in this paper.