Water. It’s crucial for life. Yet, we are finding more and more that we are without a secure supply. And, when we do find water, we need to spend lots of money- and lots of energy- to get the water to be of drinkable purity.
I’ve been trying to wake you- and everyone else- up about this issue. The last time I wrote about it was some 6 months ago- before California began rationing water. When I was describing the water-energy nexus.
Sure, we can convert sea water to drinking water. Using tons of energy – and dealing with lots of briny waste, to boot. Oh. And, we generally need water to produce energy. See thevicious cycle?
Well, maybe not. Some MIT folks, in concert with Jain Irrigation (India) may have found an approach to solve our water shortage problem. Oh, and this was not the original project that Natasha Wright thought would be her thesis.
The researchers thought the biggest problem in rural India was microbial contamination of their drinking water. Instead, they found that the biggest problem was saline (salt) intrusion. So, the project became one to employ solar energy to desalinate the brackish ground water.
This is very similar (on a much smaller scale) to the WaterFX project I described. That one isn’t for drinking water production, but for agricultural purposes- since the groundwater has been suffering from saline intrusion there, too.
Using electrodialysis (ED) for sea water purification would not make sense- because sea water is far saltier and that characteristic would render RO more useful (like the WaterFX project). But, the brackish water in these cases is much less salty, on the order of 4000 ppm (or mg/L), about 10% as salty as sea water. So, ED is perfect for this project.
This MIT project (Global Engineering and Research Laboratory) has just won the Desal Prize [the original link, now that it is old is no longer supported by the entity] , awarded by Securing Water for Food (USAID, Sweden, and Netherlands). The power to run the system is supplied by photovoltaic cells. (Electrodialysis is a membrane process, using electricity, that performs similar tasks as do ion exchangers.) In addition to electrodialysis, the MIT folks added ultraviolet light (UV) purification of the water to also eradicate microbial contamination. The system is mobile- the entire complex can be transported via tractor-trailer. Now, their job is cost-engineer the process down to $ 11K.
This is a great news! We take water for granted, and such initiatives will simply save communities.
Muriel recently posted..How My Diet Has Changed In London
Yes, Muriel, we do. Even though it is in critically short supply. (Unless we do develop that free fusion reactor that will provide power for us all- for free.)
We tend to take water for granted, but there is a shortage… http://t.co/EhH1HqVzHd
I need to make my teenagers read this…
Sounds like a plan, Marie. Let me know what they think!
Solar powered water purification | http://t.co/ne3xPqNmsp via @Adjuvancy
So this could be useful in many cases, but it sounds like it would not help the California situation, correct?
And it still does not address the microbes in India’s water, which are still an issue even if salt is a bigger issue.
David Leonhardt recently posted..Wow! Even more signs that you might be a writer
Well, it might work on some groundwater- if it is plentiful enough. But, California really needs to recover it’s wastewater (for agricultural needs), develop dual piping (so reuse can occur in the home and in industry for NON-drinking, NON-food preparation uses) or convert seawater to drinking water.
There are reasonable processes to remove the microbes (Ultraviolet light is a low power, no residue process that comes to mind.)
Thanks, David for the great queries.