How do large-scale pure water systems perform sterilization and disinfection?

一、Ozone Disinfection in Large-Scale Pure Water Systems: Ozone is a broad-spectrum disinfectant that can kill bacterial vegetative cells and spores, viruses, fungi, and can also destroy botulinum toxin. The mechanism of ozone sterilization is to destroy the structure of microorganism membranes through oxidation to achieve a sterilizing effect. Ozone first acts on the cell membrane, thereby damaging membrane components and causing metabolic abnormalities. Ozone continues to penetrate the membrane and destroy the lipoproteins and lipopolysaccharides in the membrane, altering cell permeability, leading to cell lysis and death. The mechanism by which ozone inactivates viruses is through oxidation that damages viral ribonucleic acid (RNA) or deoxyribonucleic acid (DNA).

二、Chemical Disinfection in Large-Scale Pure Water Systems: Chemical disinfection refers to the use of chemical disinfectants to act on microorganisms and pathogens, causing protein denaturation, loss of normal function, and death. Currently, commonly used disinfectants include chlorine disinfectants, oxidizing disinfectants, iodine disinfectants, aldehyde disinfectants, heterocyclic gas disinfectants, phenolic disinfectants, alcohol disinfectants, and quaternary ammonium disinfectants.

三、 Sterilization with Pure Steam in Large-Scale Pure Water Equipment: This refers to the method of sterilization using high-temperature (121°C) high-pressure steam. Due to the strong penetrability of pure steam, proteins and protoplast colloids easily denature and coagulate under moist heat conditions, and enzyme systems are also easily destroyed. The steam enters the cells and condenses into water, releasing latent heat and raising the temperature, thereby further enhancing the sterilization effect.

四、Sterilization with Superheated Water in Large-Scale Pure Water Equipment: This refers to the method of sterilization using high-temperature (121°C) high-pressure superheated water (as shown in the figure below). Like pure steam sterilization, superheated water causes proteins and protoplast colloids to denature and coagulate under moist heat conditions, destroys enzyme systems, and kills all microorganisms, including bacterial spores, fungal spores, or dormant individuals, such as heat-resistant ones. Chemical sterilization in large-scale pure water equipment: Chemical sterilization refers to the method of directly killing microorganisms using chemical agents.

五、Ultraviolet sterilization (UV) of large-scale ultrapure water equipment: Ultraviolet light affects biofilm formation by slowing the growth of new colonies in the system, but this is only effective against planktonic microorganisms. The wavelength of UV lamps used for sterilization (253.7 nm) primarily serves three functions: sterilization, degradation of TOC (total organic carbon) using UV lamps with a wavelength of 185 nm, and ozone elimination.