GCSE Combined Science (AQA)

622 videos | 38 hours

Purifying Salt Water

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Using resources Using the Earth's resources and obtaining potable water

Purifying Salt Water

4:31 Producing Potable Water
Spec 4.10.1.2
Previous Using Earth's Resources Next Producing Potable Water
  • Fresh water supplies can be limited, requiring desalination to make potable water.
  • Desalination removes salt from salt water, making it safe to drink.
  • Sea water contains high levels of sodium chloride, about 35 grams per kilogram.
  • Potable water has low levels of dissolved salts and is safe to drink.
  • Desalination is energy-intensive and expensive, making fresh water a preferable source for potable water.
  • Desalination can be performed through distillation or reverse osmosis.
  • Distillation involves boiling salt water to produce steam, which is then condensed into pure water.
  • Reverse osmosis uses high pressure to force water through a membrane, separating it from salt.
  • Both methods require significant energy and produce wastewater.
  • Wastewater from desalination, especially from distillation, is very salty and can harm marine life if not disposed of properly.
  • Understanding desalination and its methods is important for exams.

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