Swimming Pools

Disinfection is one of the key treatment steps for all types of swimming pools, either public or private. Efficient pool water disinfection is essential for public pools because of higher bather loads. In order to ensure safe bathing water, most public facilities must follow strict water disinfection standards and practices.

Trihalomethanes (THMs) - Within this group mainly chloroform is formed by the reaction between the disinfectant and organic compounds. THMs can be found in the pool water and in the air above the water. Swimmers are therefore exposed by absorption through the skin, by swallowing, and by inhalation. THMs are suspected to be carcinogenic and asthma causing, as recently stated by researchers from Belgium (BBC News, May 28, 2003).

Chloramines - Chloramines appear in swimming pools as a result of the reaction between ammonia compounds and chlorine-based disinfectants. Depending on the stage of chemical reaction, they can be in the form of either mono-, di-, or trichloramines. Chloramines are responsible for the so-called "chlorine smell", eye and skin irritations. High levels of chloramines also cause corrosion issues inside the pool enclosure.

UV water purification systems for commercial and municipal pools

Ultraviolet treatment of pool water photo-oxidizes and destroys combined chlorine and other pollutants, giving major improvements to pool environment and water quality, with significantly lower levels of chlorine. UV also provides non-chemical disinfection, giving effective primary control over waterborne bacteria, benefiting commercial and municipal pools.

Spa and hot tub establishments present difficult disinfection problems due to the high bather load and temperature. Canadian Air & Water provides fitting UV water purifiers for spas and hot tubs, including large UV units. The spa and hot tub UV water purification systems bring a dramatic improvement in water quality.

Until recently public pool operators have had little choice but to use chlorine disinfection systems, sometimes together with an ozone oxidation process. The UV water purification systems have proved that ultraviolet treatment with low levels of free chlorine has major benefits over any of these traditional methods.

The greatest benefit of UV treatment is that short-wave ultraviolet light has a photo-oxidation effect that destroys chloramines and other toxic by-products of chlorine. This is done without adding any further chemicals to the water. Much less chlorine needs to be used to provide bacterial control, so water quality and atmospheric conditions are considerably improved.

The primary UV disinfection process destroys all bacteria passing through the water treatment plant. In particular, and unlike ozone systems, this protects bathers against bacteria in the water filter media re-entering the pool.

Ultraviolet Water Purification Versus Other Systems

Ultraviolet Vs Chlorine

UV destroys these pollutants releasing free chlorine back to pool.

UV acts instantly.

Only low level chlorine residuals are necessary with UV systems.

UV cuts costs by releasing the combined chlorine.

Chlorine produces toxic by-products, which build up in water and atmosphere.

Chlorine is a slow acting disinfectant, unless concentrations are high.

Excessive chlorine is needed to overcome high organic loadings.

Ultraviolet Vs Ozone

UV plant is simple, and lower in capital cost.

UV performs the same oxidation & disinfection tasks at a fraction of ozone’s running cost.

Maintenance costs of UV equipment are lower, and do not increase significantly with age.

With UV plant simpler filter media can be used, saving carbon and chlorine costs.

It is impossible to overdose UV light.

UV treatment replaces ozone, and does not use or create any toxic chemicals whatsoever.

Ozone plant is relatively complex and costly and so is expensive to run, even when new.

Ozone plant becomes increasingly difficult and expensive to maintain.

To remove the toxic ozone before it enters the pool needs carbon filtration; this itself uses up free chlorine and increases the chemical costs.

Overdosing, and ozone entering the pool itself, is possible if ozone equipment malfunctions.

Ozone leak detection is difficult, giving rise to health & safety concerns (ozone is VERY toxic).

Ultraviolet Vs Combined Ozone / UV System

Full flow treatment UV treats all the pool water flow, at every pass.

No restriction to pool water flow.

These hybrid units only treat a small portion of the pool flow, not recommended by the Pool Water Treatment Guide.

Higher pump pressures required, possibly requiring an extra boost pump.

Additionally, the combination of chlorine, chloramines and ozone in the indoor air can be very corrosive to equipment and buildings.

UV water treatment replaces ozone and controls chloramines levels, so building maintenance expenditure is reduced.

With these advantages there are no reasons for swimmers and staff to endure an unpleasant pool environment. UV water purification systems are successfully installed and are showing chlorine reduction rates of up to 90%, at the same time controlling free chlorine levels in water to less than 1.0 ppm.

Water quality and atmospheric conditions are considerably improved, operating costs are cut and pool attendance and revenue is increased.

UV Water Purifiers for Private Swimming Pools and Spas

UV water disinfection of private pools and spas is a chemical-free method of killing microorganisms by shortwave ultraviolet light. To ensure a safe and pleasant pool environment without using strong disinfection chemicals, ultraviolet water purification destroys organic pollutants instantly as the water passes through the treatment chamber. The ultraviolet sterilization systems for private pools are particularly suitable for users who are sensitive to the usual swimming pool disinfectants, heavy metals from ionic purifiers or allergic to chlorine.

UV water purification advantages:

More pleasant bathing in a very low chemical environment

Dramatically reduced chemical dosing (50% or more) and chemical costs

Possibility of zero-chlorine bathing, using peroxide disinfectants

Unrivalled protection against contamination in swimming pool filter media

Safety-net protection against loss of chemical dosing - real life tests with no dosing for a month proved the pool water still stayed fresh

Instantaneous water disinfection at every pass

Very low power consumption

Economical swimming pool treatment – low purchase and running costs