Selection of swimming pool water disinfectant
Selection of disinfectant should meet the following requirements: and have the function of continuous sterilization; (1) does not cause water and environmental pollution, does not change the quality of pool water; (2) no irritation to the human body or irritation is very small; (3) small corrosion of the building structure, equipment and piping.
Commonly used pool disinfection methods
A pure chemical disinfection method
Injection of chemical disinfectants method, usually chlorine disinfectant, commonly used chlorine disinfectant are: (1) liquid chlorine (2) calcium hypochlorite (bleach) (3) sodium hypochlorite (high efficiency bleach, bleach) (4) dichloroisocyanuric acid sodium (Euclid) (5) trichloroisocyanuric acid (strong chlorine) (6) Bromochlorhydantoin (bromine tablets) (7) Chlorine dioxide
(1) Liquid chlorine
Advantages: Containing 100% effective chlorine, strong bactericidal force, and has a strong ability to continue to sterilize the ability of algae deodorization and deodorization. Widely used, more mature technology, disinfection system investment and operating costs are inexpensive, commonly used in water disinfection.
Deficiencies: the general dose of viruses, pathogens and other ineffective, can not oxidize the general pesticides and other complex compounds, affected by PH and some organic reaction to generate the unpleasant smell of chlorine. Liquid chlorine as a disinfectant, the human body and the environment caused by secondary pollution is also obvious, chlorine-based disinfectant itself and by-products of damage to human health. Its use is dangerous and requires special safety equipment. Liquid chlorine should be stored and transported with professional safety measures. It is particularly acidic when added to swimming pools. Need to add a lot of alkali to adjust the pH value, so, liquid chlorine in the current swimming pool has been rarely used.
(2) bleach
Advantages: The most widely used, its main ingredient is calcium hypochlorite [Ca(OCl)2], containing 25% of the effective chlorine 30%, calcium hypochlorite is a commonly used swimming pool disinfectant, the active ingredient hypochlorite can penetrate into the cells, oxidizing the cellular enzymes of the sulfur-hydrogen base, destroying cellular metabolism. It can be applied in water of different water quality conditions with good sterilization effect. In acidic environment, it has strong and rapid bactericidal power, and high concentration can kill germ cells.
Deficiency: It is unstable in nature and can be decomposed by light, heat, moisture and CO2, so it should be kept in a dark and dry place in a closed container for not more than 1 year. Because of its corrosive and bleaching effect, it should not be used for metal instruments and colored textiles. If it is stored for too long, it should be prepared according to the actual effective chlorine content. And bleaching powder reaction has residue, clogging pipes, affecting water quality, is now being phased out.
(3) Sodium hypochlorite
[NaOCl] alias high-efficiency bleaching powder. Pure product is white powder, usually gray-green crystals, unstable in air. Sodium hypochlorite has the odor of chlorine, 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. It is unstable, and the decomposition is accelerated when it meets heat. It has bleaching and corrosive effects on articles.
Advantages: Its effective chlorine content is generally 10%-12%, less dangerous than liquid chlorine, good disinfection.
Deficiencies: chlorine bleach is extremely unstable, its effective chlorine will gradually decline with the environment, temperature, humidity, light and storage time and other factors, due to its decay is particularly fast, the site can not be stored for a long time, and corrosive, so the storage and operation is very difficult. There are high demands on the equipment and routine maintenance of the equipment is difficult. Sodium hypochlorite increases the pH of the pool water extremely high and requires the addition of large amounts of acid to regulate.
(4) Sodium dichloroisocyanurate
Advantages: Sodium dichloroisocyanurate, also known as Euchlorine, molecular formula: (C3C12N3O3) Na, referred to as SDIC, for the wider use of organochlorine disinfectant, containing 60% of effective chlorine, 64.5%, with high efficiency, broad-spectrum, stability, high solubility, low toxicity and other advantages. Aqueous solution can be used for spraying, soaking, wiping, also can be used for powder direct disinfection of pollutants, treatment of feces and other excreta, the use of the same bleach. Mixed with paraformaldehyde dry powder ignition, the gas can be used for fumigation disinfection. It can also be mixed with No.92 coagulant (hydroxyaluminum chloride based on iron powder, sulfuric acid, hydrogen peroxide and other synthetic) to 1: 4 into "water clear", which can be used for drinking water disinfection. It can be used for drinking water disinfection. It can also be used with sodium nitrate to form various disinfectant washing liquids, such as Tetrameth, Euclid, etc. It can quickly kill viruses, bacteria and other bacteria. It can quickly kill viruses, bacteria and their buds, and can effectively prevent hepatitis and other infectious diseases.
Deficiencies The effect of sterilization is greatly affected by the use of conditions, sensitization of the eyes and skin, odor. It can be used as an impact treatment agent, also contains stabilizer cyanuric acid, stabilized under ultraviolet light, suitable for use in outdoor swimming pools, but in indoor swimming pools will lead to over-stabilization problems.
Trichloroisocyanuric acid Trichloroisocyanuric acid is commonly known as strong chlorine, molecular formula C3N3O3Cl3 abbreviated as TCCA, is a chlorinated derivative of isocyanuric acid, its effective chlorine content of up to 90%, mainly for the granular, flaky, strong bactericidal ability.
Advantages: Triclosanuric acid is a kind of high efficient, low toxicity, broad-spectrum and fast bactericidal disinfectant promoted internationally, which can effectively and quickly kill all kinds of bacteria, fungi, bacilli, molds and cholera bacteria. It is effective in killing Hepatitis A and B viruses, and also has good disinfecting effect on sexual viruses and HIV.
Deficiencies: Its slow dissolution may not be able to keep up with the rate of residual chlorine consumption when the pool load is high, resulting in a lower disinfecting capacity. Its low pH also requires a large amount of alkali to regulate. Trichloroisocyanuric acid contains the stabilizer cyanuric acid, which is stabilized under UV light, making it suitable for use in outdoor pools, but its use in indoor pools can lead to over-stabilization problems. At the same time, the use of trichloroisocyanuric acid will inevitably produce harmful chlorine by-products, which is the same disadvantage of chlorine-based chemicals.
(6) Bromoclorhydantoin Advantages: Bromoclorhydantoin is commonly known as bromine tablets (abbreviated as BCDMH), molecular formula: C5H6BrClN2O2, its active ingredient contains chlorine and bromine, usually crystalline powder and white tablets, bromine preparations are more stable than chlorine preparations, the odor is more mild, and is not as sensitive as chlorine to the change of pH. Disadvantages: Bromine tablets are more expensive and are slower to sterilize because they are slightly soluble in water. Bromine is corrosive in high doses, is a strong irritant to human skin, eyes and cells, and under pool conditions, produces bromate, a known carcinogen. Because bromine has no suitable UV stabilizer, it is used in large quantities for outdoor pool use.
(7) Chlorine Dioxide The formula is ClO2, a yellow-green gas with a pungent odor that is volatile. In -5 ~ 95 ° C, the quality is stable, not easy to decompose. After adding acid can be activated to produce free chlorine dioxide. It does not belong to chlorine disinfectant, but is actually a peroxide disinfectant.
Advantages: Chlorine dioxide has a strong oxidizing effect, which can oxidize and decompose amino acids in microbial proteins, leading to amino acid breakage and protein decomposition, thus killing microorganisms. It is a highly effective disinfectant that can kill a variety of microorganisms, including bacterial propagules, germ cells, fungi, viruses, and even protozoa. Fast and long-lasting disinfection, few disinfection by-products, effective killing and water quality control effect, large application PH range, wide range of applicable water quality, and strong ability to oxidize organic matter.
Deficiencies: Chlorine dioxide itself and its disinfection products are also toxic, by-products will produce chlorite and chloric acid, the combined effect of which causes mutations, sperm deformities, blood and urine chemical composition abnormalities, affecting liver function and renal failure. Organic matter has a certain effect on this disinfectant, sterilization effect is mostly affected by the concentration of activator and activation time. Chlorine dioxide requires on-site generating equipment, with large investment in equipment and high operating costs. The on-site reaction requires the use of hazardous chemicals as raw materials, all of which form a dangerous hazard.
Disadvantages of chlorine-based chemical disinfection (1) chlorine-based chemicals have a certain degree of toxicity, chlorine organic compounds in the water will irritate the eyes and skin, resulting in red eyes and rashes. Prolonged contact with pool water can cause hair discoloration and yellowing, skin redness and swelling, vaginal itching, endocrine disorders and other problems. (2) Chlorine agent will react with the organic matter in the water to generate a variety of chlorinated organic compounds, such as trichloromethane, chloroform, etc., these substances are recognized as carcinogenic and mutagenic. In particular, children are in the developmental stage and should be avoided as far as possible. (3) It has corrosive effect on swimming pool structures, equipment and pipelines; the level of operation and management is required to be high, otherwise safety accidents will occur; (4) The addition of chlorine preparation will inevitably lead to a change in the pH value of the water, which will cause discomfort to human beings, and thus alkaline or acidic substances need to be added to neutralize it. (5) Chlorine preparations are dangerous in transportation, storage and use.
Two, ultraviolet disinfection method Ultraviolet light is a low-energy electromagnetic radiation, its energy is only 5eV, poor penetration. UV irradiation energy is low, not enough to cause ionization of atoms, only to produce excitation, so that the electrons are in a high-energy state and do not disengage. Through the body of water for ultraviolet radiation penetration into the microbial body in the role of nucleic acids, plasma proteases, so that the chemical changes caused by microbial death. Generally more than 253.7nm as a representative of germicidal ultraviolet wavelength, due to the use of ultraviolet lamps is more convenient, and has a certain bactericidal effect, so the use of health epidemiological, medical and industrial disinfection are more common.
Advantages: The advantages of ultraviolet disinfection is that the required contact time is short, high sterilization efficiency, while not changing the physical and chemical properties of water, and does not produce odors and other harmful halogenated methane and other by-products.
Deficiencies: the turbidity of the raw water before disinfection requirements are high, and must ensure that a certain thickness of the water flow, when the water depth is greater when the bactericidal effect of a sharp decline in the disinfection of the water after the sterilizing effect is not sustained, ultraviolet disinfection should be the use of its specific devices, each lamp to deal with the amount of water is limited and need to be cleaned and replaced on a regular basis, the cost of the more expensive and the existence of the phenomenon of light resilience, the impact of the disinfection effect.
Three, ozone disinfection method Ozone at room temperature and pressure is an unstable lavender gas, a variety of viruses, bacteria have the ability to kill, to degrade a variety of organic toxins, in addition to the color, smell, smell, and improve the quality of the water is very effective. Its mechanism of action is to destroy the dehydrogenase of bacteria to interfere with its respiratory function, oxidize various enzymes and proteins, and destroy the cell membrane structure to achieve the effect of disinfection.
Advantages: strong oxidizing ability, can remove or reduce the odor, smell, color and metal ions in the water, and also help coagulation to lower the turbidity effect. Bactericidal effect is significant, rapid, disinfection effect by the water quality, broad-spectrum and efficient, with fewer side effects. (1) fast reaction, less investment, ozone can quickly kill the diffusion of bacteria in the water, spores, viruses and in very low concentrations both bactericidal inactivation; (2) ozone adaptability, in the PH5.6-9.8, water temperature 0-37 ℃ within the scope of the disinfection of the performance of its very small; (3) in the water does not produce persistent residue; (4) can destroy the water organisms, improve the physical properties of water and organ sensation, decolorization and side effects. and organ sensation, decolorization and deodorization and deodorization, making the water azure blue, without changing the natural nature of water.
Deficiencies: (1) ozone on algae and red nematodes and other treatment effect is poor. Ozone treatment of organic contamination of influent water, large organic molecules will rupture into the microbial metabolism of the nutrient source, the treatment of water AOC (bio-assimilable organic carbon) increased by 2-6 times, and increase the oxygen content in the water, conducive to the propagation of autotrophic microorganisms, which worsened the quality of the water is green. (2) No sustained effect, to add pharmaceutical assistance. Because of the low solubility of ozone in water, the half-life is very short, only twenty minutes, so in the daily application of sterilization to ensure the continuity of the role, often to add chlorine-based agents to assist. (3) ozone disinfection method of high equipment costs, power consumption, the use of ozone machines are often also equipped with oxygen generators, dryers, exhaust processors, etc.. These are the main reasons for limiting the widespread use of ozone disinfection. (4) Ozone is toxic. As a strong oxidizing agent, it is a good disinfectant, precisely because of this characteristic, ozone can react with almost any biological tissue, so we must pay attention to the amount of ozone generator when using it. However, current technology makes it more difficult to monitor ozone. When ozone exceeds the limit, it reacts quickly with cells, fluids and tissues in the respiratory tract, resulting in weakened lung function and tissue damage. Prolonged exposure to ozone will cause neurotoxicity, dizziness, headache, memory loss; oxidation of vitamin E in human skin, resulting in wrinkled skin, black spots and so on.
Four, copper and silver metal ion disinfection method metal ion treatment method used in the field of swimming pools in Europe, America and Japan has been quite mature, is a new generation of swimming pool treatment technology leader. Due to the metal ion treatment method using purely physical method of disinfection, treatment does not produce any harmful by-products, the water quality to meet the EU standards, because the entire process does not produce waste gas and the EU Environmental Protection Agency's recognition and recommendation. At present, it is widely used in the International Space Station, Olympic swimming pools and private swimming pools of high-grade villas. Mechanism: ① According to research, bacteria or tiny organisms in the water are generally negatively charged, silver and copper ions excited by the Ankang system are positively charged, so the copper and silver ions in the water can cause flocculation with bacteria and viruses or tiny organisms through the filtration system to flocs clear out of the pool. Silver ion reduction potential is very high, is the strongest metal ion in nature sterilization ability, as long as each liter of water contains two hundred millionths of a milligram of silver ions, can kill most of the bacteria in the water. When the bacteria were killed by Ag, Ag and by the bacterial death of the cell free, and then contact with other colonies, week after week to carry out the above process, which is the reason why the silver bactericidal persistence. ③ Copper ions on bacteria, especially autotrophic bacteria have a strong inhibitory effect and kill the role of the water can be killed in the E. coli, dysentery and other pathogens, especially to prevent green algae contamination and through the floor infected with tinea pedis and so on. At present, the usual use of a variety of anti-bacterial algaecides contain copper, is the use of copper ions can kill the principle of algaecide.
Advantages: (1) the application of PH, temperature range, applicable to a wide range of water quality, low operating costs; (2) odorless, non-toxic, overdose will not cause harm (is the human body essential trace elements, the human body to absorb the excess will be automatically discharged from the body). It will not stimulate the eyes and skin, and the water body is clear and odorless. (3) It can inhibit the growth of certain algae and fungi for a long time, and does not need to add additional algaecide copper sulfate. (4) Does not affect the PH value of water quality, no need to add pH neutralizer, because the entire reaction process without adding any chemicals, and thus will not generate harmful by-products causing secondary pollution. (5) when the contact is sufficient, a very low concentration will be able to kill the majority of autotrophic bacteria, a very long-lasting bactericidal ability, independent of light and organic concentration; (6) bacteria in the water microorganisms, turbidity, organic coloration and other colloidal suspended substances will be adsorbed by the copper-silver ions, both bactericidal and de-turbidity function.
Deficiencies: (1) Because the whole set of copper-silver ion disinfection equipment is expensive, only in the International Space Station, the domestic and foreign Olympic venues, high-grade villas, private swimming pools, recreational clubs and hotels, etc. widely used.
Swimming pool in the use of swimming pool disinfectant to disinfect, it is best to put in two times, once in the daily after the closing, and another 1-2 hours before opening. This swimming pool disinfectant with trichloroisocyanuric acid as the main ingredient belongs to the chlorine disinfectant and has volatility. The speed of volatilization is directly related to sunlight and temperature. In summer, when the sun shines fiercely and the weather is hot, the disinfectant will volatilize easily. If you add the disinfectant after the closing time every day, due to the relatively low temperature at night, there is no sunlight, you can make the disinfectant keep longer efficacy, so that you can more thoroughly and effectively disinfect the water of the swimming pool; the next day according to the opening time of each swimming pool is different, you can test the residual chlorine 1-2 hours before the opening time, if the residual chlorine is low, you can supplement the amount of chlorine. If the residual chlorine is low, the amount of disinfectant can be added in order to make the residual chlorine meet the sanitary requirements. If the disinfectant is added too early, it will evaporate quickly, and the residual chlorine will not reach the standard at the opening time. Trichloroisocyanuric acid and a series of disinfectants and germicides with trichloroisocyanuric acid as raw material, white powder, granule, slice, block, cake, globule, liquid package and other specifications, is the best use at home and abroad at present, with the widest range of adaptability, the largest amount of processing and exporting the most desirable disinfectants and germicides, no matter in the disinfecting and germicidal effect or economic price, trichloroisocyanuric acid can completely replace the previous disinfectants and germicides, to achieve high efficiency, safety and security, and to achieve a high degree of safety and health. Bactericides, to achieve high efficiency, safety, broad-spectrum and ease of use and other effects, trichloroisocyanuric acid at home and abroad has been widely used in industrial circulating water treatment, drinking water treatment, wastewater sewage treatment, swimming pool treatment, industrial bleaching, public *** places, hospitals, families, seeds, breeding disinfection and sterilization and wool shrinkage prevention and so on, almost on all the fungi, bacteria, viruses, spores have a killing effect. Solid formulations, easy to store, transport and use, safe; in addition to liquid chlorine, the highest chlorine content of chlorine-containing disinfectants, cost-effective; currently the world's swimming pool water treatment and disinfection of the most widely used agents; slow-release and immediate release of two tablets suitable for different types of dosage equipment and use; chlorine stabilizer formula, effective inhibition of ultraviolet light on the chlorine consumption loss, to maintain the chlorine content of the water in the pool slow-release type: 20 to 200 grams /tablet, chlorine content of 85 ~ 90%; a one-time put can maintain the efficacy of 5 ~ 7 days; put the dose of uniformity and continuity, effectively preventing fluctuations in the chlorine content of the pool water; used in the solid chlorine tablets doser, chlorine tablets floating cups, the pool skimmers, integrated filtration equipment, and other systems We are for the maintenance of swimming pool water quality of the other agents, specializing in solving the swimming pools, jacuzzi pools, spa pools, hot springs, water quality problems: 1, the pool water turns green first aid Treatment; 2, urea exceeds the standard treatment; 3, to eliminate the pool environment chlorine odor; 4, to kill green algae, water insects; 5, to improve the color of water and turbidity; 6, to solve the problem of metal ions in groundwater; 7, so that the water quality back to its original health, increase the blue color of the pool water; Physical and chemical properties of the product Name: trichloroisocyanuric acid (acronym TCCA) Commonly known as: Strong Chlorine Essence, disinfecting and sanitizing agent specifications: The quality of this product in line with ZBG16009-89 standard requirements: effective chlorine content ≥ 90% Molecular Formula: C3O3N3Cl3 Physical and Chemical Properties: This product is a white crystalline powder or granules, with hypochlorite stimulating odor, specific gravity of 0.96, solubility in water: 1.2 g / 100 g (25 ° C), decomposition of acid or alkali