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Disinfecting the Water using UV Radiation


Quiz Questions

1. UV radiation inactivates organisms by absorption of the light which causes a photochemical reaction that alters molecular components essential to cell function.
True
False
2. UV radiation energy waves are the range of electromagnetic waves from________________ long.
100 to 400 nm
100 to 300 nm
3. In terms of germicidal effects, the optimum UV range is between 245 and 285 nm.
True
False
4. The percent transmittance is determined from the absorbance (A) by the equation:

Percent Transmittance = 100 ‘ 10-A
True
False
5. UV lamps do not operate the same way as fluorescent lamps.
True
False
6. Typically _______________________ are enclosed in a quartz sleeve to separate the water from the lamp surface.
Low-pressure lamps
High-pressure lamps
7. Ballasts are transformers that control the power to the UV lamps. Ballasts should operate at temperatures below 60oC to prevent premature failure.
True
False
8. The major elements that should be considered in the hydraulic design of a UV closed vessel reactor are dispersion, turbulence, effective volume, residence time distribution, and flow rate.
True
False
9. An ideal plug flow reactor has no dispersion and is approximated by a long tank with high length-to-width ratio in which dispersion is minimal.
True
False
10. The rate of disinfection is indirectly related to the average intensity of the UV light.
True
False