| Title |
Factors Affecting Chemical Disinfection of Drinking Water |
| Authors |
( Yoon Jin Lee ) ; ( Sang Ho Nam ) ; ( Byong Ho Jun ) ; ( Kyoung Doo Oh ) ; ( Suk Bong Kim ) ; ( Jae Keun Ryu ) ; ( Dionysios D. Dionysiou ) ; ( Sadahiko Itoh ) |
| Keywords |
Chlorine; Chlorine Dioxide; Ozone; Disinfection; Factors; Drinking Water Treatment |
| Abstract |
This research sought to compare chlorine, chlorine dioxide and ozone as chemical disinfectants of drinking water, with inactivation of total coliform as the indicator. The inactivation of total coliform was tested against several variables, including the dose of disinfectant, contact time, pH, temperature and DOC. A series of batch processes were performed on water samples taken from the outlet of a settling basin in a conventional surface water treatment system that is provided with the raw water drawn from the mid-stream of the Han River. Injection of 1 ㎎/L of chlorine, chlorine dioxide and ozone resulted in nearly 2.4, 3.0 and 3.9 log inactivation, respectively, of total coliform at 5 min. To achieve 99.9 % the inactivation, the disinfectants were required in concentrations of 1.70, 1.00 and 0.60 ㎎/L for chlorine, chlorine dioxide and ozone, respectively. Bactericidal effects generally decreased as pH increased in the range of pH 6 to 9. The influence of pH change on the killing effect of chlorine dioxide was not strong, but that on ozone and free chlorine was sensitive. The activation energies of chlorine, chlorine dioxide and ozone were 36,053, 29,822 and 24,906 J/㏖ for coliforms with inactivation effects being shown in the lowest orders of these. |