Dive into the 2025 NY Wastewater Exam – Flush Away the Competition with Confidence!

In the operation of a disinfection system using ultraviolet (UV) light, maintaining the proper chlorine residual is not relevant because UV disinfection does not rely on chlorine as a disinfectant. Instead, this method uses UV radiation to inactivate microorganisms by disrupting their DNA, making them unable to replicate.

Factors that are crucial in UV disinfection include maintaining the optimal pH because it affects the stability of the microorganisms and the effectiveness of UV light absorption. Additionally, UV lamp intensity is important as it determines the disinfection effectiveness; the higher the intensity, the more effective the disinfection process. Water temperature also plays a role, as it can influence the viscosity of water and impact UV light penetration, thereby affecting disinfection efficiency. Thus, while chlorine residual is a critical parameter in chlorine disinfection, it is not a consideration in UV disinfection systems, which makes it the correct choice in this context.