Desalination Issues

Blog Post #352:  Desalination Issues

Taken from: https://www.scientificamerican.com/article/why-dont-we-get-our-drinking-water-from-the-ocean/ce

For years I’ve been waiting for a cheap(er) way to desalinate seawater.  I view this as one of the last frontiers in global change.

Can you imagine with me – the global change with desalination of seawater?  Deserts (like Mojave in California; Saudi Arabia could bloom; the Sahara would be green.  That could be a major economic change. One thing that all humans need is food. So, a place like Saudi Arabia can pump oil – but doesn’t have enough water (but has seawater along its coasts).  What if desalination was cheap and Saudi Arabia could have an abundance of water? They could become the next ‘Imperial Valley’ of crops and produce.

But, this article explains:

Even with all of the water in Earth’s oceans, we satisfy less than half a percent of human water needs with desalinated water.* We currently use on the order of 960 cubic miles (4,000 cubic kilometers) of freshwater a year, and overall there’s enough water to go around. There is increasing regional scarcity, though.
“So why don’t we desalinate more to alleviate shortages and growing water conflicts?
“The problem is that the desalination of water requires a lot of energy. Salt dissolves very easily in water, forming strong chemical bonds, and those bonds are difficult to break. Energy and the technology to desalinate water are both expensive, and this means that desalinating water can be pretty costly.”

The expense is significant.  But with technology (although I don’t have a clue how it would be done), I anticipate that some enterprising company will find a way to break that chemical bond between salt and water cheaply.  

We have talked about disruptive technologies before, but I think desalination of seawater will happen (maybe not in my lifetime), and will really be a ‘game changer’ for this blue planet.  (Of course, that might not be the right environment case as we would end up with mountains of salt on the shorelines of the world!!)

What do you think?

Bruce

 

Posted by Bruce White

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