| Abstract |
The aim of this study was the determination of the factors that affect the creation of disinfection halogenated by-products in swimming pool water with chlorine as the disinfection method. Chlorination of water first was used in 1850 and it is the most widely applied method of disinfection even nowadays. However, currently it is well known that disinfection by-products are created if there is organic matter in the water, which according to epidemiologic studies are toxic to humans.
Special attention was given to urea which is the main nitrogen- containing compound introduced into swimming pools by bathers mostly through urine and sweat. Urea is precursor of chloramines which, mostly trichloramine, are toxic for humans and long-term exposure to them induces asthma.
Specifically, the mobility of urea in swimming pool water was monitored in order to study how free chlorine, pH and total organic carbon affect the levels of by-product concentration and their creation. Urea was determined by high performance liquid chromatography paired with UV detector and values determined varied that vary between 0 and 4.86 mg L-1 with a mean of 1.42 mg L-1 ± 0.03 mg L-1. The advantages of this method are its speed and its easy use. Also, it is credible, reproducible and with low limits of detection in the order of ng L-1 and provides satisfactory separation of urea and allantoine even in real swimming pool water samples.
During this study it was noted that the number of bathers affects the organic load into the water, as the concentrations of TOC, urea and nitrate anions were greater in swimming pool water compared to the ones measured in drinking water treatment plant, which was found 44.4 mgTOC L-1, 1.42 mgU L-1 and 58.63 mgNO3 L-1, and to the corresponding drinking water 0.446 mgTOC L-1, n.d. and 1.531 mg NO-1L -1. Urea concentration showed a diurnal pattern of increase during the period of use fact that indicates that the reaction of urea with chlorine is too slow to be noted. Finally, it was noted that the levels of residual chlorine and urea are affected by the chlorine dose, pH and temperature.
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Μελέτη των παραμέτρων που καθορίζουν την παρουσία τοξικών αλογονομένων παραπροϊόντων απολύμανσης στα πόσιμα νερά
