How Can Water Distribution Systems Be Kept Secure?

Steve Schear schear at lvcm.com
Mon Oct 8 18:15:02 PDT 2001


At 04:30 PM 10/8/2001 -0700, mmotyka at lsil.com wrote:
>UV is actually a very good disinfectant. It works by damaging the
>DNA/RNA of bacteria and virii. There is evidence of some viruses being
>re-activated by sunlight. UV coupled with a primary disinfectant like Cl
>makes a pretty safe system. The 4ft GE Quartz UV bulbs are powerful. The
>water should be clear - turbid water attentuates the UV too much.
>
>In very poor places where many children die of dehydration because of
>contaminated water and where there is little or no money for water
>systems, aid workers have taught the kids to put water into clear
>plastic drink bottles ( the kind our landfills are clogged with ) and
>leave it in the sun. It works quite well.
>
>How are RO systems at removing microorganisms?

[From some consumer spec comparisons to a RO unit I use]

Types Of Drinking Water Appliances & Pollutants Removed

Pollutant       Sediment        Activated       Reverse Distil- De-Ion- UV
         Filter  Carbon  Osmosis ation   ization
Sodium  No      No      Yes     Yes     Yes     No
Arsenic         No      No      Yes     Yes     Yes     No
Lead    No      No      Yes     Yes     Yes     No
Cadmium         No      No      Yes     Yes     Yes     No
Cysts   No      Some    Yes     Yes     No      Yes
   (Crypotosporidium)
Sulfates        No      No      Yes     Yes     Yes     No
Calcium (Hardness)      No      No      Yes     Yes     Yes     No
Magnesium       No      No      Yes     Yes     Yes     No
   (Hardness)
Phosphates      No      No      Yes     Yes     Yes     No
Chlorides       No      No      Yes     Yes     Yes     No
Florides        No      No      Yes     Yes     Yes     No
Alkalinity      No      No      Yes     Yes     Yes     No
Fecal Bacteria  No      Most    Yes     Yes     No      Yes
Viruses         No      No      Yes     Yes     No      Yes
Organics        Yes     Yes     Yes     Yes     No      No
Trialomethanes  No      Yes     Yes     No      Yes     No
Trichloroethlene        No      Yes     Yes     No      Yes     No
Ph 
Factor       No      No      Neutralizes     Neutralizes     Neutralizes 
  No
Radioactive     No      No      Yes     No      No      No
   Contaminates
Chlorine        No      Yes     Yes     Most    No      No
Pesticides      No      Yes     Yes     Yes     No      No
Sediment        Yes     Most    Yes     Yes     Yes     No
Unpleasant      No      Yes     Yes     No      Yes     No
   Taste/Odor





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