254/185 nm photolysis of p-nitrophenol

Degradation of low-concentration p-nitrophenol (p-NP) aqueous solution was carried out in 254/185 nm photolysis. The effects of Mn2+, pH value, O2 and O3 on the degradation efficiency have been investigated. It was observed that the singlet oxygen scavenger Mn2+did not affect the degradation of p-NP. In acidic and alkaline solutions, the degradation efficiency was enhanced in comparison to that in neutral solution. The presence of O2 dramatically promoted the degradation of p-NP, while that of O3 impeded it. (authors)