How long does it take uv light to purify water to %100?

Question

I have an idea that may help us all at some point or another, but i need to know just how long it takes to purify water using this method? is it instant or does it take hours?

Answer 1

In the tropics 6 hours in a clear bottle will destroy enough of the organics to make most water drinkable.  Most  inorganic compound contaminants they will not be affected and all elemental contaminaints will  be unchanged .  (Malachi was right on this.)  Some organics can survive this treatment but they are not the ones associated with health problems (just yet).  

At higher altitudes and closer to the tropics and with clear skies the time for treatment comes down.

Answer 2

You can't purify water with just UV light.

UV is good at breaking apart some organic molecules and some microorganisms but it may also increase the growth of others.

But UV won't do a thing to inorganic contaminants such as arsenic or mercury and a zillion other pollutants.

If you want to purify contaminated water, the best way is through distillation.

Answer 3

I know people can have UV lights in their direct-flow domestic supplies, so the main bactericidal effect must be almost instant.

However, I understand that, because minute particles in the water can shelter the bacteria in their shadow, the effect is unlikely to be 100%.