We often take water for granted in developed countries. If we want to shower, wash up the dishes or have a drink, we just need to turn on the faucet and bang! Lovely, clean, potable water comes straight out.
But the reality is that water is a resource we all need to live- nobody can survive any length of time without drinking water. The problem is that water is a finite resource- there’s only so much of it in the world!
Hang on, you might think, isn’t about 70% of the Earth’s surface covered by water? Yes, that’s right. The problem is that 97.5% of that water is salt water, leaving only a tiny fraction of the world’s water as fresh water.
One thing nearly everybody knows about saltwater is that it’s not drinkable. In fact, drinking too much of it will make you ill and could even kill you.
There’s got to be a way to convert that saltwater into drinking water, right? You might have seen survival programs and wondered whether simply boiling salt water will make it safe to drink.
In this article, we’ll discover how salt water can be made into drinking water. Is boiling it enough? But first, we’ll briefly discuss why salt water isn’t drinkable.
Why Isn’t Salt Water Drinkable?
So, why can’t humans drink salt water? It would certainly be handy in a survival situation! Well, in essence, salt water is just too salty for humans to drink. Salt water is approximately 3.5% salt.
That might not sound like a lot, but it’s just too much for our bodies to process. The kidney is designed to remove excess salt from the body, but it needs water to function properly.
The salinity of saltwater is such that the kidney doesn’t have enough fresh water to counteract the sheer volume of salt it needs to process, leading to the body having to remove the salt another way- through urination.
Soon, you’ll be urinating out a lot more fluid than you’ve consumed, leading to dehydration. If it carries on long enough, this will eventually cause your organs to fail and ultimately, you’ll die.
Can You Boil Salt Water To Drink?
No, boiling salt water does not make it safe to drink. Boiling water in order to make it drinkable is a common survival technique, since it will sterilize dirty water or water you’re worried might not be clean.
The heat kills off any nasty bacteria that might be living in the water, meaning you can drink it safely.
Boil salt water, however, and you simply end up with sterilized salt water. Free of all those nasty contaminants, sure, but still very much salt water.
What you need to do is find a way of separating the salt from the water. That’s a process called desalination, and whilst it can involve boiling water, it’s significantly more complicated than just boiling it.
How Do You Remove Salt From Salt Water?
Now it’s time for some physics 101. When water gets to a certain temperature, that water will start to evaporate, forming a vapor that will escape into the atmosphere.
If that vapor is caught on a surface and allowed to cool down again, it will condense again, back into droplets of water.
This is important because when water evaporates, it leaves behind anything that may have been dissolved in it. You have purified or ‘distilled’ your water.
So really, all you need to do to make salt water drinkable is have a heat source to evaporate the water, and some kind of condensation apparatus to catch it as it turns back into drinkable, purified water.
So when you’re boiling water, you are in a way making drinking water- it’s just the steam that you want, not what’s left in the pan!
Method One: Boiling Water In A Pan
This is a method for desalinating water that you can try yourself. All you’ll need is a large pan (with lid), a drinking glass/cup, and a heat source. A metal or pyrex cup is preferred, since certain types of glass will shatter when exposed to high temperatures.
- Place your cup in the center of the pan, and add your saltwater around it, being careful not to fill the pan too close to the rim of the cup. You don’t want to contaminate your cup!
- Place your pan lid on upside down, so that the handle is hovering directly above your cup.
- Gently bring the water to the boil. Do not boil violently, as you risk either shattering your glass (if using glass) or contaminating it with drinking water.
- Watch as the steam begins to rise and accumulate on the pan lid. You’ll notice after a while that it condenses back into water, which will then begin to run down to the lid’s lowest point- the handle. From there, it’ll simply drip into your cup.
- When you think you’ve got enough water, simply remove the pan from the heat and wait for it all to cool down. When it’s cool enough, you can lift your cup right out and enjoy a glass of water!
Method Two: Solar Desalination
This method of desalination employs the same principle as the previous method, but simply uses the sun as the heat source instead. All you’ll need is some plastic wrap and two bowls, a larger one and a smaller one.
- Fill your larger bowl about half full with salt water. Then, float the smaller bowl in the center of the large bowl. Make sure the rim is some way above the water line.
- Tightly wrap the plastic wrap around your bowl, and then place a small rock on top of the wrap above the smaller bowl to create a slight dip.
- If your bowl is in direct sunlight, over time the heat of the sun will evaporate your water into steam, before it hits the plastic wrap and condenses back into water droplets. Gravity will do its job and send the droplets towards the dipped center, from where they will drip slowly into your receiving bowl!
No, you can’t just boil salt water to make it drinkable. It will be sterilized but still far too salty for the body to process. Instead, boiling water can be used as one part of a desalination technique.
You can boil salt water, catch the steam and let it condense back into water droplets. If you collect this recondensed water, it is then drinkable and salt-free.