C6.3.4 - Drinking Water Flashcards
Where does tap water come from?
Rivers
Reservoirs
Aquifers
Waste water
Why is tap water safe?
Insoluble and soluble substances within the tap water are removed at treatment areas to ensure the water is safe to drink
What does seawater contain high concentrations of?
Dissolved seawater
What is desalination?
The process of removing salt from water
What is used for small scale desalination?
Reverse osmosis using special ultra filters to filter out the salt
What is used for large scale desalination?
Simple distillation
When might desalination be worth it?
When water supply is low
Energy resources cost too low
Describe the process of how tap water is cleaned.
The water passes through a screen to catch larger objects such as twigs or leaves. It then lands in a settlement tank where soil and sand are filtered out. Aluminium sulfate and lime are added to the water to get rid of mud and dirt. Then, the water passes through a fine sand filter to remove any more mud particles. Finally, a small amount of chlorine is added to kill any bacteria