Nearly 780 million people worldwide struggle to get access to clean drinking water. The growing global population combined with the changing climate only tend to invigorate the problem. And given the fact that less than 1% of the water on our planet is considered suitable for drinking, one might say our species is facing a serious problem. Ironically, the problem is also the solution. Because, you know, there are some 5 Oceans and 113 Seas that are yet unexploited.
“But Forrest, don’t be a moron, this is salt water. We will die if we drink it.” you might say. Not if you desalinate it first.“Desalturate wut?”
Desalination is the process of removing dissolved salts from water, thus producing fresh water from seawater or brackish water.
If you do not believe me, here is the wikipedia article about it. Anyhow, salt water might be the future cure for mankind’s freshwater shortage. With the Global Warming knocking on our door, the Ocean’s levels will rise and it is gravely important for mankind to discover a way to turn salt water drinkable. If only there was an easy way …
Actually humans have been making seawater drinkable as far back as ancient Greeks. Today a lot of places scarce on fresh water do it, Chile, California, and Saudi Arabia among them. So why aren’t we doing it all over the world? Well, it is insanely expensive for starters. It also requires developed infrastructure, costly maintenance and a great many other stuff as well. To fully understand why using desalinated water for everyday uses isn’t always advisable, first we should understand how it works.
The oldest and simplest method to put in use is the thermal method. Simply said, you boil the water and collect the steam, leaving the salt and any other unwanted elements aside. It was used by the ancient Greeks to purify and make the taste of water better. The downside is it requires too much energy for the heating. To use this method today and to cleanse enough water for a city like London would require burning up all the dinosaur remains we have on Earth for a month (yes, I am talking about oil).
The second method seawater can be desalinated is trough electric currents. The idea is to catch the salt ions using a magnetic membrane, resulting in separating fresh water and salt. While it sounds more futuristic than the “heat it till it won’t kill us” technology, this method works properly only for water with low salt concentrations, as it requires way too much energy for sea water.
A third way of desalination is reverse osmosis. If you paid attention in Biology class you would know what osmosis is. I didn’t either, but after a short research I discovered it is the process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one, until there is balance in the pressure on both sides. Reverse osmosis is... just the opposite. Surprised? If it still isn’t clear to you, reverse osmosis is when outside pressure pushes the solvent trough the membrane in the opposite direction of what a normal osmosis would. If used to desalinate salt water, the salt is caught in the membrane and fresh water is distilled on the other side. And the problem with this method is, again, it is too energy-consuming when the salt concentration isn’t minute.
- Is powered entirely by renewable energy
- Has a high system water % recovery and concentrate minimization
- Has a close to zero environmental impact
- Is cost efficient, durable, and easily maintained
The winner gets the honour of being smarter and environmentally greener than the other contestants. Oh, there is also a prize of $140,000. And the project gets funded $400,000 more to be implemented in a pilot testing mode. But it is the feel of superiority that is important.
This year’s winner was a combined group from MIT and Jain Irrigation Systems. Their solution to the problem was removing salt trough electrodialysis. Simply said, water passes trough two electrodes with opposite charges. Since the salt in saltwater is composed of positive and negative ions, it is caught between them, and sterile water is produced at the end of the process. And the energy used for it all comes from solar panels. As green as it gets.
It is important to note that the whole project was designed to be used in rural Indian villages. There are several reasons why solar panelled electrodialysis is the most suitable method:
- The region’s water supplies have a low level of salinity which makes electrical desalination possible.
- In the rural areas, there is a serious lack of electrical power. Thus the whole process being powered by solar energy is a really good idea.
- Did I say the whole process is really cost efficient or otherwise said – cheap? That is pretty handy if you try to invest in a poor region without any ROI.
Surely, this isn’t like inventing fire. Solar panelled desalination plants are nothing new and there are plenty of them functioning across the globe. But what differs this project is it’s low maintenance, it’s self-sustainability and it’s functionality. By initial calculations, with this method nearly 90% of the processed salt water would be good for drinking and crop irrigation, compared to the 45% you get using reverse-osmosis. But most importantly, this is a method that is going to be put in practice soon. It will benefit greatly the life of small communities that desperately need it. It can also be used as a foundation for future similar projects and it is a step in the right direction. Because sooner rather than later we will reach our critical population and resources shall became scarce. That’s why every new innovation, any environmentally friendlier way of producing, saving or recycling water is much needed. And I shall hype as much of them as I can, because that’s the only way for our species to survive in the long term. It may sound too tinfoil-ish, but crazy preaching is better than no preaching at all. Amen, over and out!