Advanced Oxidation - a Powerful Tool for Pool Water Treatment

Swimming has become a year round activity, widely enjoyed for leisure as well as for exercise. In Germany about 250 million people visit public pools each year. Therefore pool water is regarded as a health priority which should be free of infectious feces-associated microbes such as viruses, bacteria and protozoa. Pool water disinfection with chlorine is therefore widely accepted. Further key elements of pool water treatment are flocculation and sand filtration which were derived from a single-pass drinking water treatment. In contrast to the drinking water treatment pool water is continuously recirculated to reduce heat energy and fresh water use. The continuous introduction of chlorine and organic compounds by bathers which are not necessarily similar to natural organic matter are further features of pool water chemistry. As a result disinfection by-products (DBPs) are formed at relatively high concentrations which are known to be responsible for eye and skin irritations or may cause allergic asthma [1-3]. Beside the chloramines the major DBPs in pool water are the trihalomethanes (THMs) with concentrations up to several hundreds of microgram per litre [4-6]. As potential carcinogens maximum permissible concentrations of THMs are regulated for pool water in several European countries [7]. Recent work showed that pool water may also contain genotoxic and low molecular weight compounds which are not eliminated by filtration techniques not even with nanofiltration [8].