Disinfection of Water Treatment Systems by xKzePR0

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									Disinfection of Water
 Treatment Systems




      Laura Jo Bertrand
         Josh Croll
             Joel
What is a Water Treatment
          System
• Is a form of cleansing wastes and other harmful
  microbes from water supplies.
• Reduces the risk of waterborne and foodborne diseases.
  Traditional Disinfection
          Methods
• Initially functional methods, but many microbes
  have become resistant to some treatments.
• Traditional indicators for pathogens and bacteria
  are not as effective and reliable.
• The main form of treatment, free Cl, can be
  harmful to surface water animals and may react in
  the environment to form carcinogens and
  mutagens
              OUTBREAK!!!
• Between 1978-86 111,228      • As seen from the statistics
  waterborne cases of            that with time cases seem
  illness.                       to be increasing even
• 1986-88 24 states reported     though technology should
  50 outbreaks of illness,       be improving.
  effecting 25,846
  individuals.
• 1991-92 17,464, more
  recently in 1994 an
  outbreak infected an
  estimated 403, 000 people.
Sensitivity to Disinfection




• Vegetative Bacteria > Viruses >
     Bacterial Spores = Acid-Fast Bacteria =
           Protozoan Cysts
 Microbial Test Influences
• Sensitivity varies within species or
  groups
• Prior Exposure
• Injury
• Viable but non-culturable
       Factors Influencing
          Effectiveness
•   Aggregation (clumping)
•   Dissolved organic matter
•   Inorganic Matter
•   Temperature
•   Bioreactor type, mixing
•   Attachment or colonization
  Point-of-Use Water
Treatment System (POU
         WTS)
            • Drinking water
                treatment
              • Disinfection using
                carbon block filter and
                UV light reactor.
              • Removes/inactivates
                greater than 99% of
                bacterial pathogens,
                viruses, and
                protozoan.
Disinfection of Biofilms
            • A biofilm is a microbial
              layer that forms on
              surfaces
            • Traditionaly treated with
              Free Cl
                   • Dependent on type of
                     surface biofilm is found.
                   • Free Cl used now causes
                     specific environmental
                     problems.
                   • Monochloramine is hoped
                     to be a safer and more
                     effective treatment.
               Conclusion
•   Efficiency may be site/system specific
•   In depth site studies are rarely performed
•   Indicators are useful but incomplete
•   Recent studies are directed toward the use
    better indicators

								
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