Due to innovative upgradation to pool facilities, a wide variety of fun pools and aquatic features can accommodate a larger number of patrons. Furthermore, many aquatic centers offer additional activities, including gymnasiums, kid-minding, and aqua-aerobics, and other similar games. Many pools are experiencing high bather loads as a consequence of these changes, which places high demands on the filtration and hydraulics of the pools. In this situation, ozone for swimming pool can help with disinfection of pool water.

Pool turnover times have been reduced by the use of higher recirculation rates in swimming pools or aquatic facilities with heavy bather loads. Indoor heated pools are particularly susceptible to this, with a turnover time of as little as two hours. By increasing the recirculation rate, increasing the effectiveness of the filtration, and using ozone, the water quality is increased to the highest possible level available.

A number of aquatic centers have found success with treating their pools with ozone. As a result, pool users have begun to expect that they will be able to use these facilities odor-free and without irritation to their eyes and other mucous membranes. In addition, pool water clarity plays a significant role in the general experience.

Chemistry of Ozone in Swimming Pool

In order to properly treat swimming pools by ozonation, the first and most important factor is the ability to deliver adequate amounts of ozone to achieve the desired level of oxidation and disinfection. It is possible to provide a level of water quality unattainable with normal treatments such as chlorine or bromine with ozone, but it must remain in the pool water in sufficient quantities.

This figure given above illustrates conventional ozonation procedure for waste water and drinking water treatment.

Ozone can also be used along with other treatment methods such as chlorine and bromide. To determine the size of ozonation equipment, use the following ozone injection rates. Depending on whether slip flow systems or full flow systems are used, the rates of ozone dose are mentioned.

Ozone/Chlorine Treatment

  • Pools with water temperature above 28oC – 1.0 to 1.2 mg/IO3
  • Pools with water temperature up to 28oC – 0.8 to 1.0 mg/lO3
  • Spas and fun pools– 1.0 to 1.2 mg/lO3

Ozone/Bromide Ion Treatment

  • Pools with water temperature above 28oC – 1.2 to 1.6 mg/IO3
  • Pools with water temperature up to 28oC – 1.0 to 1.6 mg/lO3
  • Spas and fun pools – 1.2 to 1.6 mg/lO3

Ozone dose rate is strongly influenced by effective turnover time and bather loading in a swimming pool. A bromine/ozone treatment is particularly challenging because the ozone must produce oxidation and bromine residuals.

Generally, the chemistry and limitations of ozonation in the pool treatment industry are not commonly considered. Before a valuable judgment of the treatment process can be made, one must gain a thorough understanding of the basic chemistry involved and the limitations of different ozone generation techniques.

In order to generate ozone at the levels shown above, UV radiation cannot be used as an ozone generator. Generally, for swimming pool treatment, a minimum of 18 grams of ozone per cubic meter of air flow must be produced.

Effect of Temperature and pH

In addition to pH, the temperature of the pool water is a significant factor affecting ozonation chemistry.

The temperature of swimming pool water and spa water is usually heated to approximately 30oC, at which the solubility of oxygen from corona discharge remains adequate for oxidizing and disinfecting the water. Water that is heated produces hydroxyl free radicals as well as molecular ozone as the dissolved ozone decomposes.

At higher temperatures, contamination derived from water will react much faster than at lower temperatures, even though this isn’t harmful. However, because hydroxyl free radicals have such a short half-life, no significant disinfectant work can be accomplished. The higher the temperature of the water, the higher the injection rate of ozone needed to carry out disinfection.

It is standard to operate swimming pools between pH levels of 7.2 and 7.8, at which level both ozone molecules and hydroxyl radicals will exist. In terms of bather comfort and maintaining correct water chemistry, this pH range has been shown to be ideal. An ozone-treated swimming pool should have pH levels within this range.

Final Words

Many businesses and general consumers today use ozone generators for water treatment of their swimming pools, and spas, which are highly effective at removing odor and microbes in the water.