Have you ever noticed a serious problem that we are lack of water, and as the economy is developing, the problem is becoming more and more serious. It's estimated that there are 3 billion people is lack of water and 40 more areas are involed. We must treasure every drop of water, also try some effort on water treatment and recycling. Ultraviolet light is proved to be efficient on killing bacteria and virous, COD degradation and odor remova on wastewater treatment. And UV lamp is now widelly used in wastewater plant, underground water recycling, industry dirty water discharged, domestic sewage.