Potable water

• What is the main difference between potable water and pure water?


  Potable water contains dissolved substances, while pure water does not.
• What term do scientists use for water that is safe to drink?

  Potable water
• What are the key steps to produce potable water from fresh water?


  Use a good source of fresh water, filter it, and then sterilize it.
• What is the purpose of filter beds in the water purification process?


  To remove materials such as leaves and suspended particles.
• How is potable water sterilized in the UK?


  By using chlorine.
• What alternative methods are used for sterilizing water in some parts of the world?

  Ozone or ultraviolet light.
• Why is fresh water scarce in some countries?


  Because the only available water may be too salty to drink.
• What is the main characteristic of seawater?


  It has very high levels of dissolved minerals.
• What is desalination?


  A process that reduces the levels of dissolved minerals in water to make it potable.
• What are two methods of desalination mentioned in the material?

  Distillation and reverse osmosis.
• Why are distillation and reverse osmosis considered expensive methods for producing potable water?


  Because both processes require very large amounts of energy.
• What are the sources of fresh water in the UK?

  • Rainwater
  • Aquifers
  • Lakes
  • Rivers
  • Reservoirs
• What steps are involved in producing potable water from salty water?

  1. Desalination to reduce dissolved minerals
  2. Methods include:

  • Distillation
  • Reverse osmosis
• What are the key characteristics of potable water?


  • Low levels of dissolved salts
  • Low levels of microbes
  • Safe for human consumption