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Abstract: Ozonia has over 40 years of experience in developing and researching ozone disinfection technologies, which have been successfully applied in water and wastewater treatment as well as in the paper industry. Experts provided a detailed introduction to the use of ozone technology in the water supply industry. Keywords: ozone, disinfection, principles of ozone generation technology. The source of gas for producing ozone can be air or oxygen, and ozone is generated after passing through a high-voltage discharge tube. Its structure includes a coolant, a ground electrode, a discharge gap, an insulator, and a high-voltage electrode, as shown in Figure 1. The moisture content in the air or oxygen has a very significant impact on the quality of the ozone produced; the lower the moisture content, the better. From the early to mid-1990s, ozone (O3) generation technology was continuously improved and refined. See Table 1 and Figure 2. Table 1: Progress in ozone generation technologies. To reduce the pollution caused to the atmosphere by emissions of residual O3, the remaining O3 is decomposed using heating and catalytic methods before being released. Its processing process is shown in Figures 3 and 4. The general treatment process for surface water in the 1990s The general treatment process for surface water in the 1990s was as follows: In the pre-ozone step, a radial diffuser was used (Figure 5) to introduce O3 into the water flow; the bubbles had a size of 2–4 mm. The main functions of pre-oxygenation were to oxidize soluble iron and manganese, remove color, eliminate odors and tastes, improve micro-flocculation, reduce trihalomethanes and their precursors, and also to oxidize cyanides, sulfites, and nitrites. Pre-ozone treatment can lay a good foundation for further water treatment. The main ozonation processes use dome-shaped porous diffusers (Figure 6) to release O3 into the water; the bubble size is 2–4 mm, and the depth of the diffusers is 2–6 m. The function of this ozone treatment process is to disinfect water, inactivate viruses and protozoa, oxidize organic compounds such as phenols, detergents, and pesticides, convert chemical oxygen demand into biological oxygen demand, and, when used in combination with biological filters, reduce dissolved organic carbon as well as the need for protective chemicals in water distribution systems such as chlorine, chlorine dioxide, and chloramines. After this O3 treatment, good water quality can be achieved. O3 technology is widely used abroad; in many countries in Europe, chlorine is used very little, or not at all, as a disinfectant. Although O3 disinfection also has side effects, its risks are much lower compared to trihalomethanes and their precursors (carcinogens) produced by chlorination, making it a relatively reliable treatment method.