What is the role of ultraviolet (UV) radiation in the water purification systems?
- It inactivates/kills the harmful microorganisms in water.
- It removes all the undesirable odours from the water.
- It quickens the sedimentation of solid particles, removes turbidity and improves the clarity of water.
Which of the statements given above is/are correct?
- 1 only
- 2 and 3 only
- 1 and 3 only
- 1, 2 and 3
Explanation
Statement 1 is correct
- An ultraviolet (UV) water treatment is a disinfection method that uses UV light to target harmful microorganisms like bacteria, viruses, and parasites like Cryptosporidium and Giardia. The UV light emits a germicidal wavelength that penetrates the microorganisms’ DNA, rendering them unable to reproduce or cause illness. With enough energy, UV radiation at the 254 nm wavelength disrupts the DNA in pathogenic microorganisms so they cannot reproduce.
Statement 2 and 3 are incorrect
- UV radiation does not have any chemical effect to remove undesirable odours. It also does not contribute to the sedimentation of solid particles or turbidity removal. These functions are usually achieved through coagulation, sedimentation, and filtration processes
