If i,m stranded on an island, how do i get the salt out of the ocean water in a most efficient way ?

Question

you never know - but it could happend == we here in canada have hundreds of isolated islands ..

Answer 1

I've heard of a device called a 'dripstone' that was used in old Europe to purify water. It's basically a stone that was shaped like a filter so water could drain through it and remove the impurities.  

If that doesn't work, you'd have to build a still. You have to evaporate the water off (can be done with sunlight) so it condenses away from it's source.  The salt will pool up in the source and have to be cleaned away.

Answer 2

I believe the most efficient way, given limited resources, is to filter the water... Put the following in a container or whatever that will allow to filter water -- rocks, pebbles, sand, soil (if carbon/charcoal is not available).

Answer 3

Since you would be stranded on an island and you don't have modern gadgets with you, the most recommendable method for you is the solar evaporation.

Solar salt is produced by the action of sun and wind on seawater or natural brine in lakes; both temperature and salinity are important. The water evaporates in successive ponds until the brine is fully concentrated and salt crystallizes on the floor of the crystallizing ponds. Solar salt plants must be located in areas of low rainfall and high evaporation rates, and where suitable low-cost is available. In the Mediterranean, for example, saltworks succeed because evaporation exceeds rainfall by a factor of 3:1; that advantage is even greater in Australia where it can reach 15:1.

Seawater contains about 3.5% (by weight) dissolved minerals. Sodium chloride is 77% of that amount, or about 2.7% of seawater. The other 0.8% consists chiefly of calcium, magnesium and sulfate ions. As seawater evaporates, its volume decreases and the concentration of sodium chloride in the resulting brine increases. Thus, saltworks generally extract as sodium chloride a bit over 2% of the weight of the influent seawater.   This means that solar saltworks are often quite extensive in area.  Often, the concentrating ponds will have distinct coloration, a pink or red, depending on the salt concentration and what species of plants and animals find it habitable.  Salt crystals begin to form when the brine concentration reaches 25.8 % sodium chloride (NaCl). As evaporation proceeds, a layer of salt builds up on the earthen crystallizer floors to a thickness of 10 to 25 cm (4-10 in). Sometimes, a layer of salt remains in the crystallizers as "salt floors" to provide support for "harvesting" equipment and to lessen the chance of clay or soil contamination of the salt. A modern, properly operated solar salt plant can produce salt that is more than 99.7 % NaCl (dry basis).  In the Dead Sea, salt producers have to contend with "salt mushrooms."

After the salt "crop" reaches the appropriate thickness, the salt is harvested (usually once a year) with mobile equipment, washed, and placed on stockpile to drain. The principal impurities in solar salt are small amounts of calcium and magnesium sulfate, and magnesium chloride. Clean brine, made by dissolving fine salt, is used to wash the salt to remove small amounts of impurities such as these. Seawater can also be used, but salt losses increase due to dissolution. Depending on the intended use, solar salt may be crushed, screened and dried in kiln or fluidized-bed dryers. Because of its high purity and large crystal size, solar salt is widely used to regenerate water softeners.

Answer 4

Hmmm.. Find some sort of container-like object, put salt water in it find something to put over the top of it that would act like a piece of plastic and let the sun do some sort of evaporation leaving clean water on the plastic object? I don't know haha

Answer 5

Well assuming that you have no equipment, this is the only way I know to do it:

Light a fire (which could take some time), then dig a hole in the sand so that the bottom fills with water. Put rocks in the fire so that they get very hot. (Be careful- don't use porous rocks, they may explode). Then slide the rocks quickly into the hole so that the water heats up. Hold a piece of cloth over the hole to catch the steam- when it cools it will be safe to drink. If you have nothing to store it in just wring the cloth out in your mouth.

Of course, if you have any equipment you may be able to make this process easier. Evaporation in general is your only way to do this; filtration and stills won't work for salt water. Of course, if you're in Canada you're quite likely to see sea ice, so know that grayish or opaque ice is salty and clear or pale blueish ice will be freshwater. :)

Hopefully you'll never need to use this info! :)

Answer 6

make an apparatus that you boil water so it turns to steam hits the top of it and condenses. Once condensed it  would slide down a tube into a glass leave the salt behind. Also know as distilled water.

Answer 7

if you are stranded on an island i think you have other things to worry about. But anyway, since you brought up the topic of water .. distillation with make shift equipment seems to be your only hope. Evaporate - condense - drink.. enjoy