Ozone (O3) is an allotrope of oxygen (O2). It is a light blue gas with a special smell. The molecular structure is triangular with a bond angle of 116°, its density is 1.5 times that of oxygen, and its solubility in water is 10 times that of oxygen. Ozone is a strong oxidant. Its redox potential in water is 2.07V, second only to fluorine (2.5V), and its oxidizing ability is higher than chlorine (1.36V) and chlorine dioxide (1.5V), which can destroy decomposing bacteria The cell wall quickly diffuses and penetrates into the cell. Glucose oxidase, which is necessary to oxidize glucose in bacteria, can also directly interact with bacteria and viruses to destroy cells, ribonucleic acid (RNA) and deoxyribonucleic acid ( DNA), RNA, protein, lipids and polysaccharides and other macromolecular polymers destroy the metabolism and reproduction process of bacteria. Bacteria being killed by ozone is caused by the rupture of the cell membrane. This process is called cell dissipation. It is caused by the cytoplasm being crushed in water. Cells cannot regenerate under dissipated conditions. It should be pointed out that, unlike hypochlorous acid disinfectants, the sterilization ability of ozone is not affected by pH changes and ammonia, and its sterilization ability is 600-3000 times greater than that of chlorine. Its sterilization and disinfection effects occur almost instantaneously. When the ozone concentration in the water is 0.3-2mg/L, bacteria can be killed within 0.5-1min. To achieve the same sterilization effect (such as the killing rate of Escherichia coli 99%), the dosage of ozone water medicine is only 0.0048% of chlorine. Ozone is also active on yeasts and parasites. For example, it can be used to remove the following types of microorganisms and viruses.
①Virus It has been proved that ozone has a very strong killing effect on viruses. For example, when the ozone concentration is 0.05-0.45mg/L, Poloi virus will lose its activity in 2 minutes.
②The cysts are completely removed after being treated for 2.4min under the ozone concentration of 0.3mg/L.
③Spores Due to the protection of the spore coat, it is 10-15 times more resistant to ozone than growing bacteria.
④Fungi Candida albicans and penicillium can be killed.
⑤The parasite Schistosoma mansoni (schistosoma mansoni) was killed after 3 minutes.
In addition, ozone can also oxidize and decompose pollutants in water, and has significant effects on deodorizing, decolorizing, sterilizing, removing phenol, cyanide, iron, and manganese, and reducing COD and BOD in water treatment. It should be noted that although ozone is a strong oxidant, its oxidizing ability is selective, and substances that are easily oxidized like ethanol do not easily interact with ozone.
