Common methods of drinking water disinfection do not include hydrogen peroxide disinfection.
Drinking water disinfection measures generally include chlorine disinfection, ozone disinfection, and ultraviolet disinfection. Chlorine disinfection is achieved through oxidation. Since both hypochlorous acid and hypochlorite have oxidizing properties, both have disinfection capabilities. As a neutral molecule, hypochlorous acid can easily diffuse to the surface of bacteria and penetrate deep into the body of bacteria, so it has strong disinfection ability, that is, under lower pH conditions, the disinfection effect will be better.
Ozone disinfection refers to water treatment technology that uses ozone as a disinfectant. Ozone is a strong oxidant. After being dissolved in water, it directly or indirectly oxidizes inorganic and organic matter in the water using a large number of hydroxyl radicals and new ecological oxygen generated in the reaction, and enters the cells of bacteria to oxidize intracellular organic matter, thereby achieving sterilization. The purpose of disinfection and water purification.
Ultraviolet disinfection, as a physical disinfection method, can avoid the problem of disinfection by-products, but it does not have the ability to continuously disinfect drinking water. It needs to be used in conjunction with chlorine-containing disinfectants to ensure that the terminal water of the pipe network has continuous disinfection ability. . Therefore, equipment with ultraviolet disinfection components is common in secondary water supply facilities, which fully takes this feature into consideration.
History of development
Historical research shows that the Egyptians first used alum to remove suspended solids in water. Presumably at the beginning of civilization, people recommended boiling water for drinking. A 4,000-year-old ancient Indian document gives the earliest drinking water standards, instructing that before drinking unclean water should be boiled, exposed to sunlight, a piece of hot copper soaked in water several times, and earthen Container for filtration and cooling.
According to historical records, Persian regulations stipulated that drinking water must be stored in copper or silver vessels. The Greek physician Hippocrates pointed out the importance of water to health, but he focused more on choosing a better water source than on water treatment. In the 8th century AD, the Arab chemist Geber used distillation to purify water.
In the 11th century AD, the Persian physician Avicenna recommended that travelers drink water filtered with cloth or boiled water. In 1627, the British scientist FBacon published a number of methods for purifying water, including percolation, boiling, distillation and coagulation. Before the establishment of the theory of bacterial pathogenicity in the mid-1880s, people believed that odor was a vector for disease transmission, and the practice of water and sewage disinfection was developed based on this hypothesis.
In the second half of the 19th century, many reports and patents appeared in Britain and the United States, mostly involving the use of voltage, magnetic field, current, chlorine, potassium permanganate and hypochlorous acid to treat water. Humanity began to actively use chemical agents for sterilization and disinfection in the early 19th century. At the beginning, chlorine-based compounds were mainly used.
For example, after bleaching powder was invented in 1820, people used it to disinfect drinking water with good results. This is the first milestone in chemical sterilization and disinfection. Since then, people have developed the second-generation disinfectant dichloroisocyanuric acid and the third-generation disinfectant trichloroisocyanuric acid in drinking water disinfectants, which are only used for small-scale disinfection. Chlorine dioxide is called the fourth generation disinfectant.
Reference for the above content: Baidu Encyclopedia-Chlorination Disinfection