Chlorine – Bromine – Ozone
Parents often ask us what exactly ozone and bromine are, which is better, and whether it is a good choice for disinfecting a pool, especially when it comes to baby swimming.
OZONE
1) What is ozone?
Ozone is a chemical compound consisting of 3 oxygen atoms. The presence of the third atom in the ozone molecule makes it particularly reactive, which is why it is often called “active oxygen”.
2) What are some of the applications of ozone?
Ozone, due to its activity, is widely used in swimming pool or spa water purification, waste purification, drinking water purification and air purification.
3) How does ozone used for water purification affect the air we breathe?
The amount of ozone produced by an ozone generator is minimal compared to the atmosphere we live in. When ozone is dissolved in water it is completely safe. Any excess ozone is immediately converted into oxygen. However, special care is required when breathing: we should not breathe concentrated ozone directly!
4) Can ozone harm me?
No. In the quantities required to be effective, ozone is harmless to the human body. However, breathing concentrated ozone can be dangerous and is strictly prohibited.
5) What is the smell of ozone?
Ozone has a distinctive odor that has been described as the smell after a thunderstorm.
6) Does ozone kill bacteria?
Yes. Ozone has a strong antimicrobial effect, one of the strongest in relation to similar substances. Yes, it helps in disinfecting a swimming pool, but it does not exempt us from the use of chlorine. Almost no physical or chemical element is fully sufficient and cannot stand completely alone except for chlorine. Only the combination of two or more alternative methods could cover the antimicrobial needs of a swimming pool.
7) Does ozone kill viruses?
Yes. Ozone can kill all known viruses in water or air.
8) What is the difference between ozone and chlorine?
In the quantities required for water purification, ozone has no particular odor, color or taste. It does not irritate the human body or wear out materials. Ozone purifies air and water quickly and effectively, 3000 times faster than chlorine. Ozone leaves no by-products except pure oxygen. On the contrary, chlorine leaves chemical by-products such as hypochlorous acid (harmful to our body) and related salts in the water, as well as fumes in the atmosphere (also harmful to our breathing).
9) Does water temperature affect ozone?
Large and sudden changes in water temperature can affect the activity of ozone. However, it is ideal as a primary or secondary disinfection element for temperatures that do not exceed 35 degrees Celsius.
BROMINE
Another method of chemical treatment of pool water is with Bromine. It is suitable for indoor pools, with higher water temperatures and in cases where we want to eliminate (almost) the presence of chlorine.
1) What is bromine?
Bromine (Br) is a chemical element similar to chlorine. It has no odor and, most importantly, does not irritate the eyes or skin.
2) What are some of the applications of bromine?
Bromine, due to its activity, is widely used in the purification of swimming pool or spa water.
3)Why is bromine considered reactive?
Because it is missing an electron to have an outer shell filled with eight electrons and to be very stable energetically, it "frantically searches" everywhere for the electron it is missing and is a strong oxidant.
4) Can bromine harm me?
Due to its high activity, bromine is not found free in nature, but combined with metals in the form of salts. In the quantities required to be effective, bromine is harmless to the human body. However, breathing concentrated bromine can be dangerous and is strictly prohibited.
5) What is the smell of ozone?
Bromine is odorless.
6) Does bromine kill bacteria?
Yes. The amines (organic compounds) produced in the water remain active, without binding the chlorine in the water, and this increases its disinfecting capacity.
7) Does bromine kill viruses?
Yes. The use of bromine as a disinfectant, yes, helps in the disinfection of a swimming pool but does not exempt us from the use of chlorine. Almost no physical or chemical element is fully sufficient and cannot stand completely alone except for chlorine. Only the combination of two or more alternative methods could cover the antimicrobial needs of a swimming pool. In fact, the chemical combination used for disinfection is 1/3 chlorine and 2/3 bromine. Also, shock chlorination remains as a process.
8) What is the difference between bromine and chlorine?
Bromine is more stable than chlorine in warm pool water, which is why many people now use it in their pools. The disadvantage is its significantly higher price compared to chlorine.
The reaction of bromine with the organic compounds in the water binds a small amount of bromine, unlike chlorine where a larger amount is bound (bound chlorine). This means that more free bromine (disinfectant) remains in the water.
In short, Bromine has the effectiveness of chlorine but at a higher cost. Due to the limited amount of chlorine it contains, it does not leave a chlorine smell in the room. It is recommended for use in indoor areas, small pools and spas.
9) Does water temperature affect bromine?
It is suitable for high temperatures. As a disinfectant it remains active even when the pH is greater than 7.8. (pH limit 7.2 – 7.8)
In conclusion the best choice for the swimming pools used by our babies and pregnant women, it is the combination of ozone - chlorine and UV rays. In the Arogi swimming pool we have sozone-chlorine combination while in Kalamaria swimming pool, ozone – chlorine – UV. Although they are quite active, ozone and bromine cannot “stand” on their own. So there must be a percentage of chlorine for 100% of disinfection. In our swimming pools, the proportion of chlorine is equivalent to that of drinking water. So it is a low percentage – and therefore fewer undesirable substances in our water – while all the rest of the disinfection is done by ozone and bromine, which do not harm us! So swim without fear!
We warmly thank Mr. Nitsa Vasilios for his scientific contribution and the writing of this article!
MD PhD, Microbiologist-Biopathologist
Vryoulon 58
Kalamaria
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