Identification and photolytic characteristics of benzoquinone intermediates in photo Fenton system

Abstract

ABSTRACT The predecessors believed that the rufous intermediates of benzene compounds degradation was quinhydrone. This article corrects this misperception. This paper takes benzene, phenol, chlorobenzene and nitrobenzene as the substrates, and p-benzoquinone as the reference; we studied the degradation law of benzene compounds in Fenton system. During the process of benzene, phenol, chlorobenzene and nitrobenzene degradation by Fenton method, it is found that the use of hydroxyl radical system for visible light would be enhanced as soon as the rufous substances were produced, which indicated that rufous substances have elevated photosensitivity. The analyses via high performance liquid chromatography, mass spectrometry, infrared spectroscopy and UV–visible spectroscopy indicate the common rufous substance is a kind of polymer formed by p-benzoquinone and oxygen. The yield of photoinduced electrons, singlet oxygen and superoxide anion radicals are carried to higher level by the rufous substance. The outstanding photosensitivity of the rufous substance provides a new idea for the treatment of wastewater containing benzene compounds by visible light.