It can be said that:

Disinfection effectiveness often improves with lower pH levels, particularly when using chlorine-based disinfectants. In an acidic environment, the chlorine species that are more effective at killing pathogens are present in higher numbers, enhancing disinfection. This relationship stems from the fact that, at lower pH levels, chlorine exists primarily in the form of hypochlorous acid (HOCl), which is a potent disinfectant.

Conversely, at higher pH levels, chlorine tends to convert to hypochlorite ion (OCl-), which is less effective in disinfection. Therefore, maintaining a lower pH can significantly optimize the disinfection process, making it essential for wastewater operators to monitor and adjust pH levels accordingly to achieve effective disinfection.

Understanding this relationship between pH and disinfection efficiency is crucial for ensuring safe and effective wastewater treatment, as it helps in the control and management of microbial pathogens in the treated water.