Potable water

• What is potable water?

  Water that is safe to drink
• How can we obtain potable water?

  By treating fresh water or desalinating seawater
• What does it mean for water to be impure?

  It contains substances other than H2O
• What are the three criteria for water to be considered potable?

  Low dissolved substances, pH 6.5-8.5, no microorganisms
• Why is pH important for potable water?

  To ensure it is not too acidic or alkaline
• What is surface water?

  Water exposed at the surface, like lakes
• What is groundwater?

  Water found underground in aquifers
• What is the benefit of using surface water?

  It is easy to access and replenished by rain
• What happens to surface water in hot weather?

  It can dry up due to sun exposure
• What is the first step in treating fresh water?

  Filtering out large particles using wire mesh
• What is the second step in treating fresh water?

  Passing it through sand and gravel
• How can we sterilize water?

  Using chlorine gas, ozone, or ultraviolet light
• What is desalination?

  Extracting potable water from seawater
• What are the two main techniques for desalination?

  Distillation and reverse osmosis
• What is the process of distillation in desalination?

  Boiling salty water and condensing vapor
• How does reverse osmosis work?

  Water passes through a membrane, filtering out impurities
• What is the outcome of both desalination techniques?

  Pure distilled water
• What are the steps involved in treating fresh water to make it potable?

  1. Filter through wire mesh
  2. Pass through sand and gravel
  3. Sterilize using chlorine, ozone, or UV light
• What are the advantages and disadvantages of desalination techniques?

  Advantages:

  • Provides a limitless supply of water
  • Useful in arid regions

  
  

  Disadvantages:

  • High energy consumption
  • Expensive to produce large quantities
• What are the sources of fresh water?

  • Rainwater
  • Surface water (lakes, rivers, reservoirs)
  • Groundwater (aquifers)