Water is present at the poles of Mars. Less plentiful than CO₂, but still, it'll be a century or more before it's depleted. Stays in ice form most of the time. Goes straight to gas when it crosses the melt point.
Agreed 100%
The perchlorate salt's removal water can be recovered, much the same way any other salt contamination can. The water exhaled by the colonists can be recovered and recyvled. Urine can be recovered and recycled. If not fermented into fertilizer, one can dehydrate fecal matter, too, and then recover and recyle that water. Even the bodies of the deceased colonists are a source of useful microbes and water.
I'm assuming you meant "The water used i the perchlorate salt's removal"
I agree that the colony is now becoming a stilsuit-based container from the Freemen of Dune?
Also fun, the perchlorate ionic group is ClO₄... an excellent source for replacement of atmospheric oxygen...
Chemical washing is a viable method of rendering the regolith suitable...
The thing is, the thing that most hinders? The lack of soil microbiotia. And even that's able to be overcome.
None of this is hard to do... it's just energy, space, and time intensive.
This is where we have an issue.
"Chemical washing" is where you wash an alien component from a native chemistry
But the perchlorate isn't alien....we are talking about washing the native chemistry out of the native chemistry.
So, we need to:
1) Isolate the soil to be used from the exterior
2) That means we have to construct sealed growing containers and transport the soil in sealed bags to prevent poisoning the colony spaces
3) Which means we need "huge" amounts of soil to be washed - and, even if we recover "every drop" we need to devote huge amounts of water "and" that means we need to supply and transport filtering and purification machinery
4) And, we need to do this again and again for every square meter of land
And, all of that needs to be built on Earth, launched into an orbital transport, shifted to Mars, land it on Mars in pieces that can be moved into the colony proper, cleaned and assembled
For every square meter of growing space.
So, where none of this is hard to do, you need the time to transport, energy, space, water and personnel -- because the water is yet another thing that has to be mined and managed.
So, in addition to the colonial operations personnel, you need:
1) Equipment cleansing, assembly and management
2) Miners and haulers to get the water to the colony
3) Farming space construction teams
4) Actual farmers
5) Miners and haulers to recover the soil to be cleansed
6) Science staff to handle the soil "washing" - if that leaves anything behind to use
--- Break caught here: the science people who do the washing will also have to handle the microbial content
7) Additional motorpool staff for the mining and recovery vehicles
See how this list is exploding for something that only "seems" easy?
Now, let's talk about the supplies needed for all these people?
Or, You already see where this is going....
So, this is hard to do.
When I worked a past job regarding the continental DataComms network, we got complaints from Puerto Rico every time a hurricane hit the island.
They demanded to see why it was taking so long compared to recovery in Florida?
The answer was, they are an island. We couldn't just order pre-prepared truckloads to drive to Puerto Rico.
Everything that "seems" easy here is not easy there.
And, it is so much more difficult if the island is 54.6 million kilometers away and requiring a lift to Earth orbit and drop from Mars orbit.
en.wikipedia.org
