Can the reaction of hydrogen peroxide and hypochlorous acid be used in swimming pools?

It can be used in the swimming pool, but the effect will be slightly worse. Swimming pools generally only use hypochlorous acid or calcium hypochlorite for bleaching.

Reason: Hypochloric acid and oxygen can sterilize, but hydrogen peroxide reacts with hypochlorous acid to produce hydrochloric acid, water and oxygen. Hypochlorite has been oxidized, and only oxygen can sterilize. (Generally, the bacteria in swimming pools are anaerobic bacteria, and oxygen can kill anaerobic bacteria), so the effect will be worse.

Suggestion: only hypochlorous acid can be used for disinfection. Reason 22HCLO = = = 2HCl+O2, ClO- itself has a certain bactericidal ability, and O2 produced by decomposition can also be effectively sterilized.

Common disinfection methods for swimming pools

One: Chemical disinfection method

Add chemical disinfectants, usually chlorine-containing disinfectants. Commonly used chlorine-containing disinfectants are:

(1) liquid chlorine (2) calcium hypochlorite (bleaching powder) (3) sodium hypochlorite (high efficiency bleaching powder, bleaching powder water) (4) sodium dichloroisocyanurate (excellent chlorine net) (5) trichloroisocyanuric acid (strong chlorine essence) (6) bromochlorohydantoin (bromine tablets) (7) chlorine dioxide.

(1) liquid chlorine

Advantages: It contains 100% available chlorine, and has strong sterilization ability and continuous sterilization ability, and has the ability to remove algae, odor and odor. Widely used, mature technology, low investment and operation cost of disinfection system, often used for disinfection in water plants.

Insufficient: General dose is ineffective for viruses, pathogenic insects, etc. And cannot oxidize complex compounds such as general pesticides. It is greatly influenced by PH value and reacts with some organic substances to produce unpleasant chlorine smell. Liquid chlorine as disinfectant causes obvious secondary pollution to human body and environment, and chlorine-containing disinfectants and by-products are harmful to human health. It is dangerous to use and requires special safety equipment. Liquid chlorine should have professional safety measures during storage and transportation. After joining the swimming pool, it is particularly acidic. It needs to add a lot of alkali to adjust the pH value, so liquid chlorine is rarely used in swimming pools now.

(2) bleaching powder

Advantages: wide application. Its main component is calcium hypochlorite [Ca(OCl)2], which contains 25%-30% available chlorine. Calcium hypochlorite is a disinfectant widely used in swimming pools. Hypochlorous acid, an effective component, can penetrate into cells, oxidize sulfhydryl genes of cell enzymes and destroy cell metabolism. Can be applied to water with different water quality conditions, and has good sterilization effect. In acidic environment, its bactericidal power is strong and rapid, and high concentration can kill spores.

Disadvantages: unstable, can be decomposed by light, heat, humidity and CO2, and should be stored in a dark and dry place for no more than 1 year. Because of its corrosion and bleaching, it is not suitable for metal instruments and colored textiles. If the storage time is too long, it should be prepared according to the actual available chlorine content. Moreover, there is residue after bleaching powder reaction, which blocks the pipeline and affects the water quality. Now it is gradually eliminated.

(3) Sodium hypochlorite [NaOCl] is also called high-efficiency bleaching powder.

Pure product is white powder, usually gray-green crystal, which is unstable in air. Sodium hypochlorite has the smell of chlorine and can be mixed with water. The solution is alkaline. The pH value of the emulsion stock solution is as high as 12, which can be reduced to 7~9 with the increase of the dilution of the aqueous solution. Sexual instability, accelerated decomposition when exposed to heat. It can bleach and corrode objects.

Advantages: Its available chlorine content is generally 10%- 12%, which is less dangerous than liquid chlorine and has good disinfection effect.

Disadvantages: chlorine in bleaching water is extremely unstable, and its available chlorine will gradually decrease with the influence of environment, temperature, humidity, light and storage time. Because it decays very quickly, it can't be stored on site for a long time, and it is corrosive, so it is difficult to store and operate. The requirements for equipment are very high, and the daily maintenance of equipment is also very difficult. Sodium hypochlorite will greatly increase the pH value of pool water, which needs to be adjusted by adding a lot of acid.

(4) sodium dichloroisocyanurate

Advantages: sodium dichloroisocyanurate is also famous for chlordecone, and its molecular formula is (C3C 12N3O3)Na, abbreviated as SDIC. It is a widely used organochlorine disinfectant, containing 60%-64.5% available chlorine, and has the advantages of high efficiency, broad spectrum, stability, high solubility and low toxicity. The aqueous solution can be used for spraying, soaking and wiping, and can also be used for directly disinfecting pollutants and treating excrement such as feces, and has the same use as bleaching powder. When it is mixed with paraformaldehyde dry powder and ignited, its gas can be fumigated and disinfected. It can also be synthesized with coagulant No.92 (adding iron powder, sulfuric acid and hydrogen peroxide). Based on aluminum hydroxide) in the ratio of 1:4, it can be used for disinfection of drinking water. Can be mixed with sodium nitrate to make various disinfection cleaning solutions. Can quickly kill viruses, bacteria and their buds, and can effectively prevent infectious diseases such as hepatitis.

Disadvantages: the sterilization effect is greatly influenced by the conditions of use, which is sensitive to eyes and skin and has peculiar smell. It can be used as an impact treatment agent and cyanuric acid as a stabilizer, which is stable under ultraviolet rays and suitable for outdoor swimming pools, but it will lead to the problem of excessive stability when used in indoor swimming pools.

(5) Trichloroisocyanuric acid Trichloroisocyanuric acid, commonly known as strong chlorine essence, is a chlorinated derivative of isocyanuric acid. Its effective chlorine content is as high as 90%, which is mainly granular and flaky, and its bactericidal ability is very strong.

Advantages: Trichloroisocyanuric acid is a high-efficiency, low-toxicity, broad-spectrum and rapid disinfectant promoted internationally at present, which can effectively and quickly kill various bacteria, fungi, spores, molds and cholera orphans. It has a special effect on killing hepatitis A and hepatitis B virus, and also has a good disinfection effect on sexual virus and AIDS virus.

Disadvantages: its dissolution is slow, and it may not keep up with the consumption rate of residual chlorine when the swimming pool load is high, which leads to the decrease of disinfection ability. Its pH value is low, and it also needs a lot of alkali adjustment. Trichloroisocyanuric acid contains cyanuric acid as a stabilizer, which is stable under ultraviolet rays and suitable for outdoor swimming pools, but it will lead to the problem of excessive stability when used in indoor swimming pools. At the same time, the use of trichloroisocyanuric acid will inevitably produce harmful chlorination by-products, which is also the same disadvantage of chlorine-based chemicals.

(6) Bromochlorohydantoin

Advantages: Bromochlorohydantoin is commonly known as Bromine Tablets (BCDMH for short), and its molecular formula is C5H6BrClN2O2. Its effective components contain chlorine and bromine, which are generally crystalline powder and white tablets. Bromine preparation is more stable than chlorine preparation, with milder smell and less sensitive to pH change.

Disadvantages: Bromine tablets are expensive, and the sterilization speed is slow because they are slightly soluble in water. Bromine preparation is corrosive at high dose and has strong irritation to human skin, eyes and cells. Under the condition of swimming pool, bromate will be produced, which is a known carcinogen. Bromine is widely used in outdoor swimming pools because it has no suitable ultraviolet stabilizer.

(7) The molecular formula of chlorine dioxide is ClO2, which is a yellow-green gas with pungent smell and is volatile. At -5 ~ 95℃, the quality is stable and it is not easy to decompose. It can be activated after adding acid to produce free chlorine dioxide. It is not a chlorine-containing disinfectant, but actually a peroxide disinfectant.

Advantages: Chlorine dioxide has strong oxidation effect, which can make amino acids in microbial protein oxidatively decompose, leading to amino acid cleavage and protein decomposition, thus causing microbial death. It is an efficient disinfectant, which can kill various microorganisms, including bacterial propagules, spores, fungi, viruses and even protozoa. Disinfection is quick and lasting, with few disinfection by-products, effective killing and water quality control effects, wide range of PH and water quality, and strong ability to oxidize organic matter.

Deficiency: Chlorine dioxide itself and its disinfection products are also toxic, and by-products will produce chlorate and chlorate, which will cause mutation, abnormal sperm, abnormal chemical composition of blood and urine, and affect liver function and renal failure. Organic matter has a certain influence on disinfectant, and the sterilization effect is mainly affected by the concentration of activator and activation time. Chlorine dioxide needs on-site generating equipment, which has large investment and high operating cost. On-site reaction needs to use dangerous chemicals as raw materials, which all form dangerous hidden dangers.

Disadvantages of chlorine-based chemical disinfection

(1) Chlorine-based chemicals are toxic. Chlorinated organic compounds in water can irritate people's eyes and skin, thus causing red eyes and rashes. Long-term contact with pool water will cause hair discoloration and yellowing, skin redness, vaginal itching, endocrine disorders and other problems.

(2) Chlorine preparation will react with organic substances in water to generate a variety of chlorinated organic substances, such as chloroform, chloroform, etc., which are recognized as carcinogens and mutagens. In particular, children are in the developmental stage, and contact should be avoided as much as possible.

(3) Corrosion of swimming pool structure, equipment and pipeline; Require a high level of operation and management, otherwise safety accidents will occur;

(4) After adding chlorine preparation, the pH value of water will inevitably change, which makes people feel uncomfortable, so it is necessary to add alkaline or acidic substances to neutralize it.

(5) Chlorine preparations are dangerous in transportation, storage and use.

Second, ultraviolet disinfection ultraviolet radiation is a low-energy electromagnetic radiation, with an energy of only 5eV and poor penetration. The energy of ultraviolet irradiation is low, which is not enough to cause atomic ionization, but only to generate excitation, so that electrons are in a high energy state without leaving. Ultraviolet rays penetrate water and act on nucleic acids and protoplasmic proteases, causing chemical changes and microbial death.

Generally, 253.7nm is the representative wavelength of germicidal ultraviolet. Ultraviolet lamp is widely used in health and epidemic prevention, medical treatment and industrial disinfection because of its convenient use and certain sterilization effect.

Advantages: ultraviolet disinfection has the advantages of short contact time, high sterilization efficiency, no change in physical and chemical properties of water, no odor and other harmful by-products such as halogenated methane.

Disadvantages: High turbidity of raw water is required before disinfection, and a certain water flow thickness must be ensured. When the water depth is large, the sterilization effect drops sharply, and there is no continuous sterilization effect in the disinfected water. And ultraviolet disinfection also needs to use its specific device, and the water treatment capacity of each lamp is limited, and it needs to be cleaned and replaced regularly, which is also expensive, and there is recovery phenomenon, which affects the disinfection effect.

Third, ozone disinfection method

Ozone is an unstable lavender gas at normal temperature and pressure, which has the ability to kill various viruses and bacteria, and has excellent effects on degrading various organic poisons, decolorizing, deodorizing and improving water quality. Its mechanism of action is to destroy the dehydrogenase of bacteria, interfere with its respiratory function, oxidize various enzymes and protein, destroy the structure of cell membrane, and achieve disinfection effect.

Advantages: strong oxidation ability, can remove or reduce the odor, odor, color, metal ions and other problems in water, and has the function of helping coagulation and reducing turbidity. The sterilization effect is remarkable, the effect is quick, the disinfection effect is less affected by the water quality, the broad spectrum is efficient, and the side effect is small.

(1) has fast reaction and small dosage. Ozone can quickly kill bacteria, spores and viruses dispersed in water, and can kill bacteria and viruses at very low concentrations.

(2) ozone has strong adaptability, and has little influence on its disinfection performance when the pH value is 5.6-9.8 and the water temperature is 0-37℃;

(3) no persistent residue is generated in water;

(4) It can destroy the organic matter in the water, improve the physical properties and organ sensation of the water, decolorize and deodorize, and make the water blue without changing the natural properties of the water.

Insufficient:

(1) Ozone has poor treatment effect on algae and red nematodes. After ozone treatment, organic macromolecules will break into the nutrient source of microbial metabolism. After treatment, the AOC (bioabsorbable organic carbon) in water will increase by 2-6 times, and the oxygen content in water will increase, which is beneficial to the reproduction of autotrophic microorganisms, and then the water quality will become green.

(2) There is no lasting effect, so it needs medication to help. Because the solubility of ozone in water is very low, and the half-life is very short, only 20 minutes, so in order to ensure the continuous sterilization in daily application, chlorine-based agents are often added for assistance.

(3) Ozone disinfection equipment has high cost and high power consumption. When using ozone machine, it is usually equipped with oxygen generator, dryer and tail gas processor. These are the main reasons that limit the widespread use of ozone disinfection.

(4) Ozone is toxic. As a strong oxidant, it is a good disinfectant. Because of this characteristic, ozone can react with almost any biological tissue, so we must pay attention to its quantity when using the ozone generator. However, it is difficult to monitor ozone with current technology. When ozone exceeds the standard, it will quickly react with cells, liquids and tissues in the respiratory tract, resulting in weakened lung function and tissue damage. Long-term exposure to ozone can cause neurotoxicity, dizziness and headache, and memory loss; It will oxidize vitamin E in human skin, leading to wrinkles and dark spots on human skin.

4. Copper-silver metal ion disinfection method The application of metal ion treatment method in swimming pool field has been quite mature in Europe, America and Japan, and it is the leader of a new generation of swimming pool treatment technology. Because the metal ion treatment method is purely physical disinfection, it does not produce any harmful by-products after treatment, and the water quality reaches the EU standard. Because the whole process does not produce waste gas, it has been recognized and recommended by the European Environmental Protection Agency. At present, it has been widely used in the International Space Station, Olympic swimming pools and private swimming pools in high-end villas.

Mechanism of action:

(1) According to research, bacteria or microorganisms in water are generally negatively charged, and excited silver and copper ions are positively charged. Therefore, copper and silver ions in water will flocculate with bacteria, viruses or microorganisms, and the flocs will be removed from the pool through the filtration system.

(2) Silver ion has extremely high reduction potential, and it is the metal ion with the strongest bactericidal ability in nature. As long as every liter of water contains two parts per million of silver ions, most++bacteria in water can be killed. When the bacteria are killed by Ag, Ag is released from the dead cells of the bacteria and then comes into contact with other colonies. The above process is repeated, which is also the reason why silver sterilization persists.

(3) Copper ions have a strong inhibitory and killing effect on bacteria, especially autotrophic bacteria, and can kill bacteria such as Escherichia coli and dysentery in water, especially to prevent green algae pollution and beriberi infection through the floor. At present, all kinds of commonly used fungicides and algicides contain copper, which is based on the principle that copper ions can kill bacteria and algae.

Advantages:

(1) Wide pH and temperature range, wide applicable water quality range and low operating cost;

(2) It is odorless and nontoxic, and excessive intake will not cause harm (it is an essential trace element for human body, and excessive absorption will be automatically excreted by human body). Does not irritate eyes and skin, and the water is clear and tasteless.

⑶ It can inhibit the growth of some algae and fungi for a long time, and does not need to add additional algaecide copper sulfate.

(4) It does not affect the PH value of water quality, and it is unnecessary to add pH neutralizer. Because no chemical agent is added in the whole reaction process, no harmful by-products will be produced and no secondary pollution will be caused.

5. When fully contacted, most autotrophic bacteria can be killed at a very low concentration, and the sterilization ability is lasting, which is not affected by light and organic matter concentration;

[6] Colloidal suspended solids such as bacteria and microorganisms, turbidity and organic chromaticity in water will be adsorbed by copper and silver ions, which has the function of sterilization and turbidity removal.

Disadvantages: Because the whole set of copper and silver ion disinfection equipment is expensive, it is only widely used in the International Space Station, Olympic venues at home and abroad, private swimming pools in luxury villas, leisure clubs and hotels.