10 - using resources

• fresh water


  contains low levels of dissolved salts
• potable water


  good quality and safe to drink
• sterilise water


  ozone or ultraviolet
• pure water


  no dissolved substances
• uk potable water produced

  1. fresh water collected from a suitable source (lake or river)
  2. passed through a filter bed to remove solid particles
  3. chlorine gas added to kill harmful microorganisms
  4. fluorine added to reduce tooth decay
• fresh produced from sea water

  desalination - evaporation and condensation
• improve taste and quality of tap water

  more dissolve substances removed by passing water through a filter (carbon, silver and ion exchange resins)