[en] Ultraviolet light is an effective method in the use of water disinfection for swimming pools, potable water and industry required water. For many reasons Ultraviolet light and Ultraviolet compounded with chlorine (Ultraviolet/chlorine) has been brought to attention ed in resent years. In this research, a swimming pool water disinfection was carried out by means of a system with the use of a reactor which was made of stainless steel (SS-304) and with many another standards required. Operation of system was carried out at first in the pilot plant and then installation in essential water treatment integrated. Inactivation of pollution index, E. Coli or Total coliform and Pseudomonas aeroginosa studies with 6000,16000 and 30000 μW.s/cm² Ultraviolet dose and then in presence of 0.3,0.6,0.9 and 1.2 mg/1 free chlorine (Ultraviolet/chlorine). In swimming pools minimum free chlorine residual usually is 1.5 mg/1. Optimum Ultraviolet dose was 16000 μW.s/cm² attention to 50 percent Ultraviolet absorption ca sued to TSS,TDS and turbidity. In the Ultraviolet/chlorine system suitable rate was 16000μW.s/cm² Ultraviolet dose/0.6 mg/1 chlorine in the 2.4 * 10⁵ CFU/100 ml for Total coliform and 3600 CFU/100 ml for Pseudomonas aeroginosa. Most probable number (MPN) estimated multiple tube fermentation technique. In this way the flow rate for system indicated about 240 cm³/s or 0.9 m³/h. The samples polluted for secondary pollution with 54000 CFU/100 ml for E. Coli and 1800 CFU/100ml Pseudomonas aeroginosa. The number of microbes decreased to zero duration after 45 minutes contact time in presence of free chlorine residual in samples. In practical conditions which that disinfectant system was installed in essential water treatment circuit under 1.4 atm hydraulic pressure no growth was seen for pollution index in disinfected water with Ultraviolet in microbial density about 840 CFU/100 ml for Total coliform and 12 CFU/100 ml for pseudomonas aeroginosa. Attention to lower turbidity, TSS and TDS in tap water, higher flow rate about 560 cm³/s or 2 m³/h accessed. Transparent materials for Ultraviolet-C in the nature is very low. Except quartz and pure water, two kind of materials, glass and polymers, were studied in this research. Experiments carried out PIXE analysis method to get special glass ingredients and another method was measuring Ultraviolet transmittances through the materials. Ultraviolet rays absorbed in the ordinary glass caused the presence of different materials oxide especially ferric oxide (Fe₂O₃). PIXE analysis shows that there is very low amount of ferric oxide with very high amount of silica in the high silica glass. Teflon, Polyethylene and Polypropylene films are polymers which have very good transmittances for Ultraviolet-C region. There is 30-80 percent transmittances for Teflon group in the 0.2-0.9 mm thickness. Teflon's don't get destroyed against destructive effect Ultraviolet-C light. For polyethylene and polypropylene films in 0.12 mm thickness, transmittances was 78 and 83 percent in ordered