• Question: How is sunlight able to purify water

    Asked by exit46paw to Philip, Maxime, Jake, Ann, Annette, Amy Heather on 19 Nov 2019.
    • Photo: Philip Schuler

      Philip Schuler answered on 19 Nov 2019:

      The radiation of the sun light kills bacteria, viruses, protozoa and worms.

      But the radiation does not remove other substances, for example heavy metals.

    • Photo: Amy Heather Fitzpatrick

      Amy Heather Fitzpatrick answered on 21 Nov 2019:

      So the UV-A and UV-B rays from the sun have different strengths. In general the UV rays cause parts of the DNA helix or strand of RNA to break or make them lose a part. This break or loss, makes it difficult for the bacteria or virus to reproduce/replicate. The longer they are in the sun, the more damage they experience and the greater the strength of the UV rays, the more damage they suffer.