Comparing UV to Chlorine and Ozone

The Customer: Colchester Leisure world, Colchester, EssexColchester Leisure world is a large modern multi-pool facility in Colchester, Essex. In mid 1996, the pool management agreed to take part in the UV System trials, as they had problems with controlling combined chlorine levels. They wished to compare the oxidizing capabilities of Daro UV Systems’ products with the ozone equipment used on some of their pools.

The Application: The management suggested their 150m³ teaching pool should be used, as it is situated in a self-contained part of the building and the effects
of UV treatment on the atmosphere could also be studied. The teaching pool is a popular facility and irregular demands are often put on the chlorine levels. Prior to the UV installation the free chlorine level was between 1.5 mg/l and 2.0 mg/l and combined chlorine 1mg/l. An independent research consultancy and pool staff conducted tests and the trial was formulated in consultation with the local Environmental Health department.The Results: Their main findings are summarised below:

• Immediate 75% reduction in combined chlorine levels
• Combined Chlorine fell from 1.0 ppm to stabilise at around 0.15 ppm
• Free chlorine was reduced to 0.6 ppm residual free chlorine
• Organic content of water (UVC absorbers) was improved by around 75%.
• The pool ‘no longer suffers from chlorinus smells’ – the atmosphere is
  much better than in the rest of the building
• Staff have commented on improved water clarity

Andrew Talbot, Technical Manager at Leisureworld, had no prior experience of this technology but can now report that the equipment has worked brilliantly. He said of the plant:

"After only two weeks of use, there has been substantial improvement in water quality and real environmental benefits."