Water Purification Technologies - Ultraviolet (UV) Radiation

Ultraviolet radiation has widely been used as a germicidal treatment for water. Mercury low pressure lamps generating 254 nm UV light are an effective means of sanitizing water. The adsorption of UV light by the DNA and proteins in the microbial cell results in the inactivation of the microorganism.

Recent advances in UV lamp technology have resulted in the production of special lamps which generate both 185 nm and 254 nm UV light. This combination of wavelengths is necessary for the photooxidation of organic compounds. With these special lamps, Total Organic Carbon (TOC) levels in high purity water can be reduced to 5 ppb.

Table 7. Ultraviolet Radiation
Advantages Disadvantages
  • Effective sanitizing treatment.
  • Oxidation of organic compounds (185 nm and 254 nm) to < 5 ppb TOC.
  • Decreases resistivity.
  • Will not remove particles, colloids, or ions.

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