Tennessee Wastewater Operator Practice Exam

The presence of which type of particles can scatter UV radiation during disinfection?

1. Organic matter particles

2. Inorganic particles

3. Turbidity particles

4. Microbial particles

The correct answer is: Turbidity particles

The presence of turbidity particles is significant in the context of UV radiation scattering during the disinfection process. Turbidity refers to the cloudiness or haziness that is often caused by a variety of suspended particles, including organic and inorganic matter, and microorganisms. These particles can obstruct the passage of UV light through the water, leading to reduced effectiveness of UV disinfection systems. When UV light is used for disinfection, its ability to inactivate pathogens in water relies on direct exposure to the light. If the water contains turbidity, these particles can absorb or scatter the UV radiation, preventing it from reaching and effectively treating the microorganisms in the water. Thus, managing turbidity is crucial for optimizing UV disinfection processes, ensuring that the water is adequately treated and safe for consumption. While organic matter, inorganic particles, and microbial particles can also affect UV disinfection, the term "turbidity particles" specifically encompasses all suspended materials that can block light. This makes it the most comprehensive choice for discussing the scattering of UV radiation during the disinfection process.