Physical method is to use heat, ultraviolet radiation, ultrasonic high-frequency radiation and other methods to coagulate protein in bacteria under the action of physical energy, or to mutate genetic factors and change the genetic characteristics of bacteria, so as to achieve the purpose of disinfection. The chemical method is to inactivate the special enzymes of microorganisms by using inorganic or organic chemicals, or destructively degrade the cytoplasm of bacteria through violent oxidation reaction to achieve the purpose of sterilization.
Among them, the common physical methods are: heating method, gamma radiation method and ultraviolet radiation method. Common chemical methods include: adding alkali or acid, adding surface active chemicals, adding oxidants (chlorine and its compounds, bromine, iodine, ozone) and other disinfection methods. In practical application, liquid chlorine or chlorine dioxide is most commonly used for disinfection.
Effect of chlorine dioxide on disinfection of drinking water
Chlorine dioxide is a very effective water purifier for purifying drinking water, including good deodorization and decoloration ability, efficient sterilization and virus killing ability at low concentration.
Chlorine dioxide is used for disinfection of water. When its concentration is 0.5 ~ 1mg/L, it can kill 99% bacteria in water within 1min. The bactericidal effect is 10 times that of chlorine, 2 times that of sodium hypochlorite, 3 times that of chlorine and 1.9 times that of ozone.
Chlorine dioxide has the characteristics of fast sterilization speed, wide pH range (6- 10), unaffected by water hardness and salt content, long sterilization time, effective elimination of protozoa, spores, molds, algae and biofilm, no production of chlorophenol and trihalomethanes, and oxidation of various organic compounds, thus reducing the toxicity and mutagenicity of water.
The above contents refer to Baidu Encyclopedia-Chlorine Dioxide Baidu Encyclopedia-Drinking Water Disinfection Technology.