Portable Desalination: How to Filter Salt Water Like a Boss
There’s a large chance you’ve learned about salt water the hard way: by drinking it. That swimming trip was draining you and you probably figured it would be fine to take a gulp of the ocean. To your shock, you just ended up thirstier.
Did you know that while the Earth is 70% covered in water, 97% of that water is salty? According to Fairfax Water, “Two percent of the water on earth is glacier ice at the North and South Poles. This ice is fresh water and could be melted; however, it is too far away from where people live to be usable.”
The website continues to say that, “Less than 1% of all the water on earth is fresh water that we can actually use. We use this small amount of water for drinking, transportation, heating and cooling, industry, and many other purposes.”
Imagine being able to turn all that saltwater into potable drinking water. That would solve a lot of problems. This is especially true for people who live near the ocean or in places where clean water is hard to come by. All that unusable water suddenly becomes a rich source of life-giving fluids. This guide will teach you how to do exactly that.
Why is the Sea Salty?
You already know it’s salty, but you’re not really sure why. What you’re tasting isn’t pure salt. They’re sediments from the multitude of minerals that have been dissolving into the ocean since the ocean was there in the first place. You’re tasting history.
On the plus side, that doesn’t mean you have to put up with history. Filtering salt water can be as easy as twelve letters. It’s called desalination, and it’s easier than you expected.
What is Desalination?
In order to filter salt water, all you need is a dish pan. While water is affected by rising temperatures, salt isn’t. It salt stays behind. What you’re left with is a dish pan with some salt after you leave it alone for a few hours. That’s the most basic kind of saltwater filter you can use at home.
Of course, you can’t drink salt. That’s why you need a different way to separate the salt from the water This is where a solar pan comes in. You’ve probably seen one in those “stranded on an island movies”. Protagonists place salt water in a bowl with a cup in the middle. Over the whole contraption, a plastic sheet is placed with a hole in the middle. As the water vapor rises from the salt water, it condenses on the surface of the plastic cover and drips into the hole in the center, where the glass is waiting. It’s really effective if you only drink water every other day. It’s the simplest salt water filtration system on a shoestring budget.
Because of how ridiculous that sounds, a more efficient way had to be created. You need to increase the speed at which the separation occurs and increase the amount of water that you’re processing in order to have a sustainable model. That’s where distillation comes in. Understanding this process is the first step to learning how to filter salt water.
MORE ARTICLES ON DISTILLING WATER:
What is Distillation?
Using evaporation and condensation on a more controlled scale, distillation will heat the water until it evaporates. After that, the water vapor is subjected to lower temperatures in another chamber, catalyzing the process. Instead of waiting for the sun to come up and down, you induce these temperatures to get the desired effect. It happens faster and you end up with more water. You’re looking at a gallon after a few hours. That’s not so bad when you look at a homemade solar pan.
Although it sounds good and easy to do, you would need fuel and coolant that would host the evaporation and condensation processes. That makes distillation an expensive method, but don’t worry, there’s still reverse osmosis.
Here are some of our own portable water distiller recommendations:
What is Reverse Osmosis?
Primarily, forward osmosis desalination is the process of subjecting two substances to a membrane that is designed to separate them from each other. You simply let the densities of the two substances do all the work to separate on their own.
With reverse osmosis, you pass the water through a desalination filter using hydraulic pressure. Many large scale salt water filters use this method to get rid of salt and other water contaminants. They use a large desalination pump that forces the dirty water through the filter to remove all the salt.
In large wastewater treatment plants, reverse osmosis is done through tubes that have several different layers made from really thin membranes that take out plenty of water contaminants including salt.
On a scale this large, you could be looking at several hundred tubes filtering water fed at high pressures. This water gets filtered through reverse osmosis several times before it goes back into the drinking system.
How to Make a Water Desalinator
People living near oceans with short supplies of fresh drinking water could use a few desalination techniques to solve the shortage of drinkable water. Unfortunately, not every place has access to a large reverse osmosis plant that can clean gallons of salt water.
Fortunately, you can perform personal desalination by creating your very own salt water filter for drinking. Now that you’re aware of the principles behind desalination, it’s time to put those principles into some workable steps.
Here’s what you’ll need to create your own personal water desalination kit:
- 2 Pots
- Aluminum Foil
- Rubber Tubing
1. Create the desalination chamber by covering one pot with aluminum foil. Make sure to leave a small opening for the rubber tubing.
2. Fasten the rubber tubing to the opening and make sure that this connection is airtight. That will create the evaporation case for the salt water purifier.
3. Run a certain portion of the rubber tubing through the inside of the second pot. This will be your condensation chamber. Later on, you will fill that with some ice water. This will create the condensation chamber for your saltwater to freshwater filter.
4. Use the glass jar as a collection unit for your desalinated water. Position the free end of the rubber tube into the mouth of the jar.
How to Use it
Place your salt water in the pot with the aluminum foil. This is where the magic happens. Position this pot on top of a stove. Any gas burner will do as long as you can get the water to boil.
Make sure that the pot with the foil and the other pot are on the same level. You might want to use a chair or table to elevate both of these pots.
Finally, ensure that the glass collection jar is on a lower level compared to the two chambers. This will allow the distilled water to flow down into the jar thanks to gravity.
How it Works
In the desalination chamber, the water is heated in an isolated space. This is where the dirty water turns into water vapor. Since water vapor cannot hold salt, the vapor rises and leaves the salt at the bottom of the desalination chamber.
You’re not just getting the salt out. You’re also leaving out any other solid particles that may have made their way into your water. That includes parasites, metals and dirt. Expect to clean out that pot after every use.
Once the water vapor has released all its salt content, it has to go somewhere. That’s where the rubber tubing comes in. It will transport the water vapor from the first chamber to the second one. The ice in the second pot will cool the air vapor as it passes, condensing the pure air vapor.
When this happens, the vapor returns to a liquid state, sans the salt. This is the drinkable result.
Using gravity to bring it on home, the purified water simply drips into the glass jar. That’s why it’s important to make sure that the collection jar is lower than the condensation chamber.
Problems You May Encounter
There’s no doubt about how clean this contraption gets your water. The problem here lies in the energy you need to use to get it done. Take note that you need a large amount of heat to get water to evaporate. That’s 100 C.
You would need to keep the stove running for a good thirty minutes to get a good drink of water. That might cost more than a bottle of mineral water. That’s why this method is considered as an emergency desalination kit for those cases when you have no other choice.
There’s also an issue of sustainability. Because of the quality of the materials you use, you might have to keep replacing them at certain points. The rubber tubing isn’t going to stay clean forever. You’re also going to need a steady supply of aluminum foils if you plan to use this contraption for long periods of time.
Finally, there’s also an issue with portability. It won’t do great on camping trips. You’re not going to find a salt water purifier portable if you plan on making one yourself. That’s why you need to look into commercial purifiers that have solved these issues.
Desalination Solutions Available Online
In order to circumvent the problems of using conventional fuels, filtration manufacturers have used different methods to improve their desalination kits. Some have created solar-powered desalinators that use solar energy to power up the heating system. Instead of burning fuels and gas, a solar-powered portable desalination unit can heat water using solar energy.
Some have even come up with hand-powered devices that work well on boats. These portable water desalination systems can be found all over the web. Many non-profit programs aim to make portable water desalination possible.
Here are some of our own portable water desalinator recommendations:
So should you get a desalinator?
As a homeowner, a portable desalination system is one of the best investments to make.
Even though you have your own filtration system at home, there’s no telling when your water supply will become compromised. This is especially true if you live near the ocean or if you go travelling. In a world where basic commodities are getting harder and harder to come by, a personal desalination device could be a lifesaver.
Check out this video to get a better idea of just how possible DIY desalination can be with just a few odds and ends from your home. Excellent!