Sanitary hand shields
PROBLEM TO BE SOLVED: To provide a device for oxidation, sterilization and purification by UV rays in which the repetition time of maintenance such as cleaning of a filter material and an ozone lamp is small and contamination in the external piping system due to the back washing of the filter material can be prevented. SOLUTION: Filter layers 3 are disposed in the tank 2 of the device 1 for oxidation, sterilization and purification by UV rays, and ozone lamps 6 are disposed in the upper space 5 of the tank 2. Raw water is subjected to the oxidation and sterilization effect of the ozone lamps 6, filtered by the filter layers 3 and discharged as treated water. During back washing, the pollutants depositing in the filter layers 3 are subjected to the oxidation and sterilization effect by the ozone lamps 6 and then discharged to the outside. Thus, contamination of the external piping system by the discharged water can be prevented. Since the filter layers 3 are always oxidized and sterilized by the ozone lamps 6, the layers are clean and the repetition time for maintenance is small. Since the dirt depositing on the lamp tubes of the ozone lamps is polished away by the floating filter material during back washing, a small number of the repetition time for maintenance is required.