Detection of reactive oxygen species generated by microwave electrodeless discharge lamp and application in photodegradation of H2S

The photodegradation of hydrogen sulfide (H2S) was examined using a self-made microwave electrodeless discharge lamp (MEDL). The features of the MEDL had been tested. The results showed that the MEDL absorbed 18.3, 32.7 and 41.8W power at the microwave (MW) output power of 165, 330 and 660W, respectively. The intensity of the emitted light increased with increasing MW output power. The reactive oxygen species (ROS) generated by irradiated air and nitrogen were detected, respectively. It was illustrated that the irradiated air could generate a number of ROS, at least including 1O2 and ·OH. And the amount of ROS increased with increasing MW output power. In photodegradation of H2S process, the effects of MW output power and gas composition were investigated. The removal efficiency of H2S under nitrogen was obviously lower compared with that under air. The removal efficiency of H2S increased with increasing MW output power.