At 04:30 PM 10/8/2001 -0700, mmotyka@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

[Reformatted for legibility. When posting tables, use spaces, not tabs, keep total width <= 73 characters, and compose in a monospaced font, unless specifying field delimiters. KMSelf] At 04:30 PM 10/8/2001 -0700, mmotyka@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 No No Yes Yes Yes No (Hardness) 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 Neutr Neutrl Neutr 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