Instructables

Plastic bottle desalination

EDIT: In light of recent information " There's always a 'GOTCH' to a good idea isn't there....

With this system (and all systems that use plastics as evap-chambers/collectors) is that the plastic should be UV stable and BISPHONOL free.

Most plastics used in the drinks industries are not made for permanence in UV rich envirinments. Also, some of the temperatures generated in the evaporation base will radiate heat into the surrounding plastics helping to free toxic elements such as bispenol and other yucky plasticisers.'

I think that it is necessary to warn everyone NOT to use this device for anything other than exploring the basic principles of evaporation as a method of desalination (not that
 I genuinely believe that anyone would because the design really isn't that great .....) 

In my country (Australia) one of the biggest current issues is water conservation, and in some areas, the development of desalination plants. There are those who are for Desalination and argue that it will have a positive effect on rapidly diminishing water supplies. And there those who are opposed to it, becuase they don't like the idea of large machinery being operated near beaches and areas that have not been affected by development. Or, simply because they can't quite stomach the idea that drinking water may have previously played host to human excrement.

I'm all for desalintation, because i think that the benefits it offers are far greater than the problems tat it could cause. In this instructable I will show you how to modify a plastic bottle so that it can desalinate small amounts of water using heat energy from the sun.

Desalination: The removal of salt or other excess minerals from water through a variety of methods.


This is an entry into the keep the bottle contest, please take the time to vote, any support is greatly appreciated.
 
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kenwork3 years ago
If you were to push the top down so that the top faces the drain, would that not make the process faster? Concentrating the evaporated/re-condensed water towards the drain..
gmark3 years ago
Could this be used as a solar powered still?
There's always a 'GOTCH' to a good idea isn't there....

With this system (and all systems that use plastics as evap-chambers/collectors) is that the plastic should be UV stable and BISPHONOL free.

Most plastics used in the drinks industries are not made for permanence in UV rich envirinments. Also, some of the temperatures generated in the evaporation base will radiate heat into the surrounding plastics helping to free toxic elements such as bispenol and other yucky plasticisers.
well that is one huge "GOTCH" :/ thanks for pointing it out.
I'll put a warning in.
teslafan1004 years ago
cool! :)

lemminggenocide (author) 4 years ago
thanks for all the comments! sorry I haven't replied though. I should mention that a lot of you have pointed out a fatal flaw in my design, the collection chamber, does not have a lid, or anything to stop the water evaporating out of it. This problem can be easily fixed however, by either adding a lid to the chamber and cutting a hole in it's side for the water from the evaporation chamber to come through. you could also paint it white to keep it as cool as possible. Once again thatnks for all the comments.
This is really cool. I knew you could desalinate by evaporation, but the mechanics of doing it with items you have on hand isn't always easy. Good description. For even faster results maybe try a black plastic garbage bag as a collector held up like a tent over a depression in the sand filled with saltwater. Of course, then you'd have to put something all along the edge of it to collect the fresh water.
Very cool, but wouldn't the distilled water evaporate from its container? Could you fix this by building something to hide the clean water container in the shade, but not dirty water container?
scubagal5 years ago
This is a great idea and I am sorry I am a bit "dense" on this. Do you put a smaller bottle of salt water inside the larger plastic bottle and the pure water condenses on that and drips?
This method also works for purifying water. In fact it can be a perfect method to purify urine in the desert since the hotter the better and the outgoing liquid is 100% pure H2O.
KEUrban5 years ago
Cool idea. How long does it take to desalinate a litre of water, and can the bottle be reused to desalinate more?
lemminggenocide (author)  KEUrban5 years ago
the bottle can be reused, just take out the drain give it a little wipe and your good to go.
lemminggenocide (author) 5 years ago
thanks for all of the feedback Pyro13 & Biopyro: I will try to add some more photos to the instructable, thanks for letting me know. Threecheersfornick: Thanks for the info, I think that i didn't express myself very well when a blamed the photos on my camera, what I should have said was that I am not a very good photographer. Hoopajoo: Thank you for pointing out a big problem with my instructable. Instead of using open top containers/ glasses, I would suggest using a small plastic bottle, cuting a hole in the lid and putting a straw through, then attatching the straw to the end of the drain. Cheers LG (real initials (AL)
The quality of your pictures has nothing to do with your camera. A six mega-pixel camera should produce an image bigger than your screen at perfect-looking quality. The problem is that your pictures somehow got compressed when they were uploaded, degrading the picture quality. I don't know why this happens, but it happened to me too. Just so you know.
pyro135 years ago
Very cool idea! My only recommendation is to add photos to go along with your diagram.
Biopyro5 years ago
Your photos are absolutely excellent! 2MP is ample here. My only criticism would be to add photos to accompany the diagrams.
Hoopajoo5 years ago
Nice concept! How would you keep the water in the glass outside the container form evaporating too?
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