According to the type of soluble color, compounds and atomic structures, the color in sewage and wastewater treatment and color removal by nano ozone system is practical. True color is created by compounds that absorb visible light.Ozone color removal system is used at the outlet and after chemical and biological treatment, the amount of ozone is determined according to the quality of the outlet waste, temperature and previous processes and used nano ozone system. In case of using the real nano ozone system, the performance of the system shall be increased and the capacity of the ozone generator will be significantly reduced.The quality of color …