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Void

Member

Registered: 2011-12-29

Posts: 7,753

Salt, Water, Power, Crops.

I think that the use of salt water and fresh water could aid in the habitation of Mars.

The following is a potential source of power, if salt and fresh water were available:
http://news.stanford.edu/news/2011/marc … 32811.html

A source of salt could be salt pans:
http://digital.csic.es/bitstream/10261/ … 264561.pdf

Typically it is expected that water would have to come from ice, but it can be noted that the salt pans may have a source of moisture in them.  I would think that if no life exists in them then the salt pans can be used.

Here is someones invention where a salt water concentrate is generated, and fresh moisture from that process is utilized to irrigate fresh water crops:
http://en.wikipedia.org/wiki/Seawater_greenhouse

That sort of fits, but I actually want to see salt water enclosures on Mars where crops are grown, and the evaporation from the soil or plants or water surface if there is one is then condensed on the greenhouse walls.

Such greenhouses could be lower pressure to increase evaporation rates.

Here are some proposed crops:

Salicornia Europaea

Atriplex

Salt water is relative.  It does not have to be as salty as the oceans of Earth.

Here are some links:
http://sciencefocus.com/qa/are-there-an … salt-water
http://blog.jove.com/2012/05/24/japanes … ccelerator
http://gigaom.com/cleantech/salt-loving … -jet-fuel/
http://en.wikipedia.org/wiki/Salicornia_europaea
http://en.wikipedia.org/wiki/Atriplex
http://news.google.com/newspapers?nid=1 … 22,7428244

So, a waterworks, an energy source and a food source.  Not for free of course.  Structures have to be built.

Anyway now I don't have to carry this one around anymore.

Oh, additionally it would be possible to have a dome with ambient pressures with a ice covered pool in it where in addition to the evaporation process, the freeze process of the day night cycle might help to push brine out of the ice layer during the night, and then during the day, the heat would sublimate the less salty ice into a vapor, which would then have to be compressed to condense into fresh water.

Not having to make the dome covers hold pressure might be a plus.  They would still need to be vapor tight, which is not easy.

Last edited by Void (2012-12-28 11:06:34)

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SpaceNut

Administrator

From: New Hampshire

Registered: 2004-07-22

Posts: 29,428

Re: Salt, Water, Power, Crops.

Another blast from the past to which we are talking about lakes currently in materials...

Void

Member

Registered: 2011-12-29

Posts: 7,753

Re: Salt, Water, Power, Crops.

OK, if that method is indeed valid, and since you mentioned lakes!!!!!

This link is interesting and has to do with U.V. in Antarctic Dry Valley Lakes.

http://aslo.org/lo/toc/vol_43/issue_4/0618.pdf

Since I am having trouble getting reference materials, I will just describe what I think I know about such lakes, how I think they might work out on Mars, and how this could relate to salt water power.

The lakes are each different I believe, however, the pattern is generally;
-An ice cover with little or no snow, where some sunlight can penetrate.
-A upper layer of less salty and colder water where O2 is concentrated.  In fact if you drill a hole in the ice the water will bubble with Oxygen coming out.
-A lower layer which is anoxic and warm and very salty.  Easily can approach or exceed room temperature.
-Small organisms live in the lakes like algae which produce the Oxygen.
-This is a natural salt pond solar collector.
http://adsabs.harvard.edu/abs/1980STIN...8110568V
-I believe that the salt inversion is due to brine that is expelled from freezing winter ice, and also the fresh water that flows to the tops of the lakes seasonally perhaps for about 2 weeks a summer.

Creating analog lakes on Mars of this will require intentional manipulations. 

On Mars we will be able to use both the cold or night and the solar heat of the day to generate both brine concentrates and fresh water.

The reservoir will hold cool water with less salt and warm water with more salt.  So, energy wise it could be regarded as a giant battery, that you might be able to swim in, may grow vegetables in, and may have habitats in.

If this can be true:
http://news.stanford.edu/news/2011/marc … 32811.html

Stanford researchers use river water and salty ocean water to generate electricity

Stanford researchers have developed a rechargeable battery that uses freshwater and seawater to create electricity. Aided by nanotechnology, the battery employs the difference in salinity between fresh and saltwater to generate a current. A power station might be built wherever a river flows into the ocean.

Then the lake can provide energy, 24-7 around the year regardless of dust storms.

So for the cold side separation of water into greater and lesser salty components, a radiator may operate surface much of the time, where heat is extracted from the water, and that heat vented to the outside environment.  (Turbine optional).  Inside the lake you might hope to create a slush which will expel brine.  The brine delivered to the bottom of the lake, the slush floating up.

So, for the hot side separation of water into greater and lesser salty components, I might propose that solar concentrators heat a suitable fluid, in the sunshine, which will include what the U.V. can offer, which is a lot.  The hot fluid conveyed into the lake, may heat water to boiling, generating steam which of course will be your fresher water, and leaving behind a brine concentrate. (Turbine optional)

And so you recharge the battery.  Internal to the lake, you may generate power from salt and or thermal differences.

The down side of this is your built materials inside the lake waters must tolerate salt.  But that should be a problem which could be overcome.

http://www.swide.com/art-culture/nemos- … 2015/09/30

After all diving bells are being used near Italy to grow vegetables.

Now as for the lower warm layers of water being anoxic, that is not a requirement.  It could be highly Oxygenated instead, and you could have diving gear that can extract Oxygen directly from the water.  Therefore you might be on the bottom with just swim trunks, and that breather, and pick up rocks or whatever.

http://www.livescience.com/3829-inventi … -fish.html

Should this be an advantage over normal scuba gear it might be facilitated by charging the lower warmer saltier layers with more Oxygen.  Oxygen could be added up to the level where it would "Fizz" out of the water due to lack of sufficient pressure per Henry's law.

I do not think that the colder upper water which would be under less pressure could hold enough Oxygen for a diver to breath from it with this apparatus.

And this method also requires that the water not turn over.  Further I suspect that over time the charged Oxygen on the bottom will migrate upwards through dissolution, and will bubble out to form bubbles under the ice, so this then has to be managed the bubbles suctioned and compressed and returned to the lower layers.

As you can see, your lake, particularly it's lower layers can serve as an Oxygen reservoir.  Handy to have during the winter, or during a dust storm.

But of course this topic primarily is about power from salt differentials.

Last edited by Void (2015-11-26 15:22:54)

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SpaceNut

Administrator

From: New Hampshire

Registered: 2004-07-22

Posts: 29,428

Re: Salt, Water, Power, Crops.

Bumping related idle topic

Mars_B4_Moon

Member

Registered: 2006-03-23

Posts: 9,776

Re: Salt, Water, Power, Crops.

Algae as Food and Ingredient: From Production to Consumer Acceptance
https://www.frontiersin.org/research-to … acceptance

Designing the 'perfect' meal to feed long-term space travelers
https://www.spacedaily.com/reports/Desi … s_999.html

Algae, Microalgae & Seaweed
https://vegconomist.com/category/algae- … e-seaweed/