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Naked Scientist: Is there a DIY method to extract salt from seawater?

2 February 2018 11:38 AM
Tags:
sea water
desalination
Cape Town water crisis
salt water
Naked Scientist Chris Smith says there are methods but it's really tricky.

With Cape Town's Day Zero fast approaching, there have been questions about the kinds of methods that can be used to save the city from a permanent drought.

Cape Town is intensifying pressure management on the water supply system to reduce the rate at which water flows to properties.

Desalination has been one of the suggestions.

This caller says he has tried some home experiments to remove salt from seawater.

Chris Smith shares the challenges around desalination.

The reason the sea is salty is that it is energetically difficult to get salt out of water once it is in there and it takes the sun in the sky shining and illuminating the surface of the sea to evaporate fresh water and give us the fresh water that we have.

Chris Smith, Naked Scientist

It is energetically very demanding doing this which is why it costs a huge amount of money to do desalination.

Chris Smith, Naked Scientist

Researchers are looking for alternative ways to do this, but there is no such thing in physics and chemistry as free lunch, so you have got to put the energy in to break apart the bonds between the water molecules because there are bonds holding the molecules to together and that is what stops it easily turning it into steam and then you boil off the water and collect the steam.

Chris Smith, Naked Scientist

One way of doing it is with desal by putting in electrical heating, another way is to use the heat of the sun, you could also light a fire.

Chris Smith, Naked Scientist

Click on the link below to find out more...


2 February 2018 11:38 AM
Tags:
sea water
desalination
Cape Town water crisis
salt water

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