Most of our regular swimming takes place in artificial pools, where the water circulates and relies on disinfectants for purification. How much do you know about the classification of disinfectants and disinfection principles? Therefore, this paper summarized the common disinfectants and their advantages and disadvantages.
Bleaching powder (calcium hypochlorite)
Advantages of calcium hypochlorite
The most widely used, its main component is calcium hypochlorite [Ca(OCl)2], containing 25% to 30% of effective chlorine, calcium hypochlorite is a commonly used disinfectant in swimming pools, the effective component hypochlorite can penetrate into cells, oxidize cell enzyme sulfur gene, destroy cell metabolism. It can be used in water with different water quality conditions and has good bactericidal effect. In acidic environment, its bactericidal power is strong and rapid, and a high concentration can kill spores.
Calcium hypochlorite deficiency
It is unstable in nature and can be decomposed by light, heat, humidity, and CO2. Therefore, it should be kept in a dark and dry place for no more than 1 year. Because of its corrosion and bleaching effect, it is not suitable for metal equipment and colored textiles. If it is stored for too long, it should be prepared according to the actual available chlorine content. And the residue after the bleaching powder reaction, blocking the pipeline, affecting the water quality, is gradually eliminated.
Sodium hypochlorite
[NaOCl] alias High efficiency bleaching powder. Pure products are white powder, usually gray-green crystals, which are unstable in air. Sodium hypochlorite has a chlorine odor and is miscible with water. The solution is alkaline. The pH value of the emulsion is as high as 12, and with the increase of the dilution of the aqueous solution, the pH value can be reduced to 7~9. The sex is unstable, and the decomposition is accelerated in case of heat. It has bleaching and corrosion effect on articles.
Sodium hypochlorite advantages
The effective chlorine content is generally 10%-12%, which is less dangerous than liquid chlorine and has good disinfection effect.
Insufficient sodium hypochlorite
The chlorine content of floating water is highly unstable, and its effective chlorine will gradually decrease under the influence of factors such as environment, temperature, humidity, light, and storage time. Due to its fast decay, the site can not be stored for a long time, and it is corrosive, so it is difficult to store and operate. There are high demands on the equipment, and the daily maintenance of the equipment is also difficult. Sodium hypochlorite will greatly increase the pH of the pool water, requiring the addition of a large amount of acid regulation.
Sodium dichloroisocyanurate
Sodium dichloroisocyanurate advantages
Sodium dichloroisocyanurate, also known as euchlorine, molecular formula: (C3C12N3O3)Na, referred to as SDIC, is a widely used organic chlorine disinfectant, containing 60% to 64.5% effective chlorine, with the advantages of high efficiency, broad spectrum, stability, high solubility, low toxicity. Aqueous solution can be used for spraying, soaking, rubbing, can also be used for powder direct disinfection of pollutants, treatment of feces and other excrement, use the same as bleach powder. Mixed with paraformaldehyde dry powder and ignited, the gas can be fumigated. It can also be mixed with No. 92 coagulant (hydroxyl aluminum chloride based on the synthesis of iron powder, sulfuric acid, hydrogen peroxide, etc.) to 1: 4 into “water clear”, which can be used for drinking water disinfection. And can be prepared with sodium nitrate into a variety of disinfection washing liquid, such as polyester Jingmei, euchlorine and so on. It can quickly kill viruses, bacteria, and their spores, effectively preventing hepatitis and other infectious diseases.
Sodium dichloroisocyanurate deficiency
The sterilization effect is greatly affected by the use conditions, and it is sensitized to the eyes and skin, and has odor. It can be used as a shock treatment agent, also contains the stabilizer cyanuric acid, stable under ultraviolet light, suitable for use in outdoor pools, but use in indoor pools can cause over-stability problems.
Trichloroisocyanuric acid
Trichloroisocyanuric acid, commonly known as strong chlorine essence, molecular formula C3N3O3Cl3 for short TCCA, is a chlorinated derivative of isocyanuric acid, its effective chlorine content is as high as 90%, mainly granular, sheet, strong bactericidal ability.
Trichloroisocyanuric acid advantages
Trichloroisocyanuric acid is an effective, low-toxicity, broad-spectrum and fast disinfectant that can effectively kill various bacteria, fungi, spores, molds and vibrio cholerae. It has special effects on killing hepatitis A and hepatitis B viruses, and also has good disinfection effect on sexual viruses and HIV.
Trichloroisocyanuric acid deficiency
It dissolves slowly and may not keep up with the rate of residual chlorine consumption when the pool load is high, resulting in a reduced disinfection capacity. Its pH is low and also requires a lot of alkali regulation. Trichloroisocyanuric acid contains the stabilizer cyanuric acid, which is stable under ultraviolet light and suitable for use in outdoor pools, but can cause over-stability problems when used in indoor pools. At the same time, the use of trichloroisocyanuric acid will inevitably produce harmful chlorine byproducts, which is also a common shortcoming of chlorine chemicals.
