The background
Swimming pools are always aspiring to have as good water quality as possible for their visitors. Continuous disinfection is a well-known necessity, but part of keeping good quality is also to avoid the build-up of contaminants due to savings in water supplementation, such as bound chlorine, halogenated organics and micropollutants. Excessive build-up of contaminants can lead to difficulty in bath maintenance and loss of comfort for visitors and staff.
The case
Dryden Aqua’s AFM® filter material easily removes inorganic chloramines from swimming pools, but strongly-bound chlorinated organics might build up due to the absence of biology in the AFM® filter. Because of this Dryden Aqua wanted to combine their technology with advanced oxidation to remove extra strongly-bound chlorinated organics and any other micropollutants from the water such as pharmaceutical and cosmetics.
The solution
For the application of Advanox™ in swimming pools Van Remmen UV Technology developed new Advanox™ reactors to fit swimming pools of 80-500 m3. The AFM® was set-up to treat the whole bath once every 2-3 hours, and the Advanox™ every couple of days to a week in a side-stream.
Results
The system was demonstrated successfully November 2019 through February 2020 at Bad Hesselingen in Meppel (the Nederlands), and then again in September through November 2020 at an instruction pool in Breitenbach (Switzerland). During the first test the combined chlorine was reduced by half compared to the same period the previous year. During the second trials the process was optimized and the combined chlorine could easily be kept constantly at <0,15 mg/l.
The micropollutants found were mostly cosmetics, and each pass through the Advanox™ reactor removed on average >80% of the micropollutants. Micropollutants were naturally and continuously added to the swimming pool through visitors, but over the course of a month the swimming pool saw a 40% reduction of micropollutants. In this case a lower removal is ideal because the 40% removal per month adds up to almost complete removal over timeframes longer than 3 months of continuous use. This results in a treatment that removes exactly what is needed without wasting energy and expenses.
