Tennessee Wastewater Operator Practice Exam

What is a significant disadvantage of using ultraviolet radiation for disinfection of wastewater?

1. It requires minimal maintenance

2. High costs and scattering of UV by turbidity

3. Fast acting with immediate results

4. Easy installation and low energy consumption

The correct answer is: High costs and scattering of UV by turbidity

Using ultraviolet (UV) radiation for the disinfection of wastewater does present significant challenges, particularly related to cost and effectiveness in conditions where water quality is compromised. High costs are associated with the installation and operational aspects of UV disinfection systems, as they require specialized equipment and maintenance. Additionally, the presence of turbidity in the wastewater can scatter UV light, reducing its efficacy in inactivating pathogens. This means that if the water is not sufficiently clear, the required dose of UV radiation may not penetrate effectively, resulting in suboptimal disinfection performance. Therefore, concerns about costs and the impact of turbidity are valid considerations in the implementation of UV disinfection systems for wastewater treatment.