Photocatalysis and Blue Light in Swimming Pools Delay Corrosion in Concrete and Metal Parts and Improve Indoor Air Quality

Västertorpsbadet aquatic center in Stockholm, Sweden, opened in 1967, had its original hypochlorite-based water treatment system combined with a photocatalysis treatment for the water and blue light in the pool hall. This case study follows up the outcome of these installations. When chlorine was reduced from 0.8 to 0.4 mg Cl2/l levels of culturable bacteria did not raise, and also all other indicators remained well within the Public Health Agency of Sweden’s guideline values. In addition, air quality in the pool hall was much improved because concentration of trichloramine in the air was reduced. When chlorine and chloride in the pool water is reduced, risk for corrosion is reduced, which will give extended service life both for reinforced concrete in the pool and in the building and in all steel details such as ducts, pipes and fixtures. In our literature research, we have not found any other similar approach to reduce chlorine addition in a swimming pool. In conclusion we found a good technical effect from supplementing the hypochlorite addition with these methods.