What is the science behind water purification?

Three ways:
  1. Evaporation (boiling), when pure clean water rises as steam.
  2. Physical and chemical treatment (filtering and chlorinating).
  3. Pressure and reverse osmosis. Water is forced through membranes that only allow pure water through.
The science is:
  • testing can tell you if the raw water is reasonably safe
  • big lumps settle out
  • lumps can be filtered out
  • organics and odours can be oxidized or stripped out
  • viruses and bacteria can be killed with chlorine
  • testing can tell you if the treated water is acceptable