Generally, ozone is generated by using silent discharge or surface discharge; however, the energy efficiency of ozone generation by using only one kind of discharge is about 200 g/kWh. The energy efficiency of ozone generation is about one-fifth of the theoretical energy efficiency. Ozone decomposition occurs at high concentrations, high temperatures, and so on. In order to increase ozone generation efficiency, many studies of ozone generation methods have been carried out to date.
Experiments on ozone generation by using surface discharge and UV rays were carried out. In an experiment on superposing surface discharge and UV rays in the same space, the ozone yield by the superposing mode is lower than either the ozone yield by surface discharge or by UV rays at the same power. It appears that noticeable ozone dissociation by UV rays occurs because a high ozone concentration is achieved by the superposing mode. In cascade connection of a surface discharge reactor and UV lamp reactor, the ozone yield of the cascade mode (from the UV lamp reactor to the surface discharge reactor) is higher than that of the superposing mode at the same power. It is confirmed that cumulative disassociation is an effective reaction of ozone generation.