| Title |
A comparative study on the safety of drinking water disinfected with chlorine ( Cl2 ) and chlorine dioxide ( ClO2 ) |
| Authors |
옥치상 ; 정용 ( Chi Sang Ok ; Yong Chung ) |
| Abstract |
For the purpose of reducing the risk by chlorination of drinking water, this study was carried out to predict the risk of drinking water by chlorination and to manifest the influence of disinfectants, chlorine and chlorine dioxide. Productions of Trihalomethanes (THMs) and nonvolatile extractable organic matter (EOM), and the Salmonella mutagenicity by the disinfection were investigated. Cl₂ and ClO₂ with their concentrations of 1㎎/ℓ, 5㎎/ℓ and 10㎎/ℓ, respectively were mixed as the ratio as l : 1, 1 : 2. And the influence by the disinfection with Cl₂, ClO₂ and mixture of Cl₂/ClO₂ in water added with humic acid(10㎎/ℓ) and raw water (3rd quality) for 2hrs and 24hrs were evaluated. The results were summarized as follows; The formation of THMs and EOM, and mutagenicity showed that in comparison with Cl₂ disinfection, 1 : 1 mixture of Cl₂/ClO₂ decreased in 45-65% THMs, 26-56% EOM and 20-40% mutagenicity ; 1 : 2 mixture of Cl₂/ClO₂ decreased in 73-85% THMs, 58-63% EOM and 30- 55% mutagenicity ; ClO₂ disinfection decreased in 95% THMs, 66-70% EOM and 40-60% mutagenicity, respectively. All of mutagencity were increased according to the increase of EOM in plate. Based on the assessed above results, it is concluded that the chlorine dioxide would be one of the alternatives of disinfectants in drinking water. However, in view of prevention of water born disease by pollution during distribution of tap water, the mixed disinfect of Cl₂/ClO₂ could be recommended. |