A new photon kinetic-measurement based on the kinetics of electron-hole pairs in photodegradation of textile wastewater using the UV-H_2O_(2FS)-TiO_2 process

摘要

Actual textile wastewater and synthesized wastewater containing various textile dyes were photocatalytic degraded by the UV-H_2O_(2Fs)-TiO_2 process in an annular-flow photocatalytic reactor. In this process, a photon kinetic-measure was adopted to obtain constant rates of dyes decomposition. It was theorized that, by illumination at different UV frequencies, the electrons within the semiconductor were excited from the valence band to the conduction band, yielding the formation of electron-hole pairs which are the pre-requisites for photocatalysis. CPT (critical photonic time) exposure required to cause 90% of vibrations between the double and single bon3s along the molecular chain of the dyes to be oxidized, was taken to measure the photocatalytic activities. The CPTs varied with the frequencies of the UV spectral areas. The derivatization of CPT from the first-order kinetic law was presented.