At which pH level does chlorine destroy bacteria most rapidly?

Chlorine is most effective as a disinfectant at a neutral pH level, which is around 7 pH. At this level, chlorine exists in an optimal form that can easily penetrate bacterial cells and disrupt their metabolic processes, leading to effective bacterial destruction. As the pH rises above 7, the disinfecting properties of chlorine decrease due to the formation of less effective chloramines rather than hypochlorous acid, which is the more potent form of chlorine at lower pH levels. Similarly, at acidic levels, while some forms of chlorine remain effective, the rate of disinfection may not be as high as at neutral pH due to the overall activity of chlorine being affected by acidity. Therefore, the effectiveness of chlorine as a bactericide peaks at or around a pH of 7.