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Latest research confirms that Mars soil would be good for crop-growing including tomatoes, which would be nice as one of my favourite foods!
https://www.degruyter.com/view/j/opag.2 … 9-0051.xml
Mars soil is much, much better than lunar soil for plant growth.
This is great news.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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Peas and tomatoes. That's good to know. If tomatoes can grow, so should potatoes. Take some chickens along, and we can have pasta (gnocchi) in tomato sauce. Or just potatoes with ketchup, and vicodin once we run out of ketchup.
Take goats along, and we could have a complete diet. Though potatoes are pretty nutritious on their own, far better than grain. Boil them, mash them, put them in a stew... there's a lot you can do with taters.
Use what is abundant and build to last
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Sounds like we can use Mars soil as a treatable growing medium for crops with a bit of added organic matter, maybe in the form of liquid plant food...
Using transparent low pressure concentrated CO2 habs, with maybe reflectors intensifying the insolation, we might get v. good results.
Last edited by louis (2019-10-25 16:05:46)
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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The mars soils is old news and still favorable for what it could grow from the pheonix lander but they are making no meantion of the hazards of the soil toxins...
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Here is the Potatoes can grow on Mars.
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None of these address the issues we have discussed on this form. How do you effectively remove perchlorates? How do you reduce salt without washing away nutrients? One concern was excess iron in Mars soil, these studies prove that isn't a concern. The initial post said "The simulants were mixed with organic matter to mimic the addition of residues from earlier harvests." Ok, so how do you grow the first crop? I have suggested treated Mars regolith with water to decompose superoxides, and to use soda water (seltzer) formed by adding Mars atmosphere (95+% CO2) under pressure to water for several hours. That's carbonic acid, a weak acid that should react with alkali in Mars soil to move the pH toward neutral. It would also add initial carbon. Add ammonium nitride fertilizer to add nitrogen. That should grow many crops. But then Mars Phoenix discovered perchlorate. Uhhh... Adding soda water will partially break down perchlorate, but...
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I think perchlorates are one of those "bogeymen" of Mars (remember over the years we have been told there will be virtually no water on Mars, planetary capture is impossible, retro rocket landing is impossible, and the dust will kill us) that will disappear on closer inspection.
For one thing there is a suggestion that the perchlorates are at a higher proportion on the surface. If we dig down we may get a better quality soil. If we rinse the soil, are we sure there isn't some way of separating off the nutrients from the perchorates? And are there no other methods of removing perchlorates e.g. through sifting and so on?
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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I'm not saying it can't be done. But it will have to be dealt with. An article in "Sky and Telescope" from January 2018.
Some Plants Grow Well in Martian Soil
One major difference between the Villanova project and real Martian soil is perchlorate (CClO4). Perchlorates abound in the uppermost layer of Martian regolith, potentially lowering the freezing temperature of water enough to explain some fleeting signs of liquid water activity on Mars.
But perchlorate is toxic to humans, causing thyroid problems and even death. Humans on the Red Planet might breathe it in from dust that infiltrated habitats, and growing food with it would be dangerous. “Matt Damon would have died,” Guinan said, referring to the Hollywood version of the novel. “It was never mentioned in the movie, you know — you don’t want to talk about things like that.”
Farmers on Mars will need to remove any perchlorate from the Martian soil before using it. One way is to rinse the soil, since perchlorate dissolves in water. Another, more enticing way is to use perchlorate-eating bacteria, which produce oxygen as a metabolic byproduct. That might protect the colonists from serious health problems while also bolstering their breathable air supply.
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For RobertDyck re #8 ...
The quote you provided includes two methods for processing Martian regolith to remove perchlorates.
Both of those look like business opportunities suitable for inclusion in My Hacienda as representative of Division of Labor and Specialization that will occur naturally in a community of any size, and specifically of the size of Sagan City (2018).
A specialist in either of those activities should have an ample market. One will be superior to the other (that is always the case) but both should find sufficient market share to survive despite competition with each other.
I would bet on water washing given my present state of knowledge, but the bacteria solution does look interesting because of the oxygen byproduct, which in itself would have significant monetary value, and (perhaps even more important) an essentially limitless market.
(th)
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The article points out perchlorate dissolves in water, but I'm concerned that washing soil would wash way necessary nutrients as well. This Wikipedia article says estimate is Mars soil has 60% Ca(ClO4)2 and 40% Mg(ClO4)2. That breaks down in to CaCl2 (road salt) and MgCl2 (minor ingredient in road salt, coagulant used to make tofu, and magnesium fertilizer). Oxygen is released. So how do we break down perchlorte?
Bacteria produce an enzyme called perchlorate reductase that works:
ClO4− + 2 AH2 ⇌ ClO2− + 2 A + 2 H2O
Where "A" is an electron acceptor. So this releases water. What is "A"? And is this enzyme stable?
Is there a catalyst that will do it?
Efficient Heterogeneous Catalytic Reduction of Perchlorate in Water
Abstract
A new heterogeneous catalyst that promotes the reduction by hydrogen of perchlorate ion in water under mild conditions has been developed. The catalyst is prepared by adsorption of a rhenium(VII) precursor (either ammonium perrhenate or methylrhenium trioxide) onto carbon powder containing 5% palladium by weight. Under standard batch conditions of room temperature, 1 bar of hydrogen, and 200 ppm perchlorate (as HClO4), reduction proceeded to less than 1 ppm in as little as 5 h. Extended reaction times led to residual perchlorate at low parts per billion levels. Chloride was the only observed product, with good material balance. Catalytic materials ranging from 3% to 13% Re showed (pseudo) first-order rates linearly dependent on the Re content. Representative normalized rate constants for catalysts with 5−9% Re were in the range 0.1−0.3 L h-1 (g of cat.)-1. Inhibition by chloride was not significant, with little change in perchlorate reduction rate in the presence of excess chloride to 1000 ppm. However, optimal activity occurred in acidic solutions (pH ca. 3), and both the rate and extent of reaction decreased at higher values of pH. In its current form the catalyst might be best applied to destroy perchlorate in the acidic regeneration stream from selective ion exchange columns.
A bioinspired iron catalyst for nitrate and perchlorate reduction
Biological inspiration for reduction
Microorganisms have evolved sophisticated enzymatic machinery to reduce perchlorate and nitrate ions. Although the energetics of the pathways are different, the heme-containing active sites of the corresponding reductase enzymes are remarkably similar. Ford et al. constructed an inorganic catalyst to mediate these reactions based on these active sites, using a nonheme iron complex. A secondary coordination sphere near the iron center aligned the nitrate or perchlorate oxyanions and formed an iron-oxo complex. Regenerating the catalyst in the presence of protons and electrons released water—a potentially much more sustainable process than reduction strategies that require the use of harsh reagents.
Abstract
Nitrate and perchlorate have considerable use in technology, synthetic materials, and agriculture; as a result, they have become pervasive water pollutants. Industrial strategies to chemically reduce these oxyanions often require the use of harsh conditions, but microorganisms can efficiently reduce them enzymatically. We developed an iron catalyst inspired by the active sites of nitrate reductase and (per)chlorate reductase enzymes. The catalyst features a secondary coordination sphere that aids in oxyanion deoxygenation. Upon reduction of the oxyanions, an iron(III)-oxo is formed, which in the presence of protons and electrons regenerates the catalyst and releases water.
And a more negative review:
Catalytic and electrocatalytic reduction of perchlorate in water – A review
Abstract
Although perchlorate (ClO4−) is a trace of emerging contaminant in ground and surface water system, it has a detrimental effect on human health. Catalytic/electrocatalytic reduction has attracted increasing attention to remove ClO4− from water because of the fast and permanent conversion of ClO4− into innocuous chloride (Cl−). However, there are also many problems that hinder its implementation, i.e., the lower removal efficiency and catalytic activity to ClO4−, the poorer selectivity toward desired reduction products (Cl−), the easier deactivation of catalysts or electrodes. This paper critically reviews the state of knowledge in the field of catalytic/electrocatalytic reduction of ClO4− so as to find better methods to overcome these weaknesses. Specifically, the review summarizes the reported researches related to (1) proposed reaction mechanisms, (2) approaches to improve catalytic/electrocatalytic reduction of ClO4−, (3) inhibition and fouling of catalyst and electrode, (4) prospecting the advantages and barriers of this technology. This review will significantly improve the understanding of the detail processes and mechanisms of ClO4− reduction by catalysis/electrocatalysis and provide fundamental and useful information and data to scientific research and actual practice.
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For RobertDyck re #10 ...
Thanks for that treatment of the subject!
http://www.rsc.org/periodic-table/element/75/rhenium
Rhenium has no known biological role.
Natural abundance
Rhenium is among the rarest metals on Earth. It does not occur uncombined in nature or as a compound in a mineable mineral species. It is, however, widely spread throughout the Earth’s crust to the extent of about 0.001 parts per million. Commercial production of rhenium is by extraction from the flue dusts of molybdenum smelters.
I was unable to find definitive information about availability of Rhenium away from Earth, but it certainly would be a valuable material if it can be found. The Google results for Rhenium were impressive.
(th)
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The second paper is an iron-based catalyst. Iron is a lot easier to get. I can't read the full text because I don't have a paid membership with AAAS. (pay-wall)
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My overall feeling is that, for an early colony, creating enough soil for agricultural production is probably not a very sensible way of going about things. Assuming 0.3 hectares per person ie 3000 sq. metres (54x54 metres) of soil, you'd end up needing 30,000 sq metres for a colony of ten. If the average soil depth was 0.5 metre, that would be 15,000 cubic metres of soil. If it was a ton per cubic metre that would be 15000 tons. As there's a lot of air in soil, so let's make that 10,000 tons. Creating 10,000 tons of anything is quite a task for a colony of ten - and they will already be focussed on water mining and producing rocket fuel.
Probably hydroponics, using imported nutrient solution is the best way forward initially. Over time, it should be possible for the Mars colony to start producing its own nutrient solution using organic waste, human faeces and other material from the Mars regolith. It is unlikely that even hydroponics will produce even a majority of the food. A colony of 1000 people will need about 500 tons of food per Earth year. In many ways it would make sense to continue importing food. If the colony imported 70% of their food from Earth, that would be 350 tons. But maybe 30% could come in the form of dried food stuffs, so perhaps saving 70 tons on that 350, reducing it to 280 tons. So only requiring 3 Starships per annum, or 6 every two years, for a colony of 1000.
Producing real Earth-like soil will be a huge undertaking, that will probably only make sense when we get to the stay of creating large domes on Mars.
Of course, the good thing about soil is that having created it, you can use it again and again as long as you treat it right and it makes a good choice if you are engaging in natural light farming.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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The Mars Odyssey orbiter has also detected perchlorates across the surface of the planet. The NASA Phoenix lander first detected chlorine-based compounds such as calcium perchlorate. The levels detected in the Martian soil are around 0.5%, which is a level considered toxic to humans.
https://www.nasa.gov/mission_pages/msl/ … 21203.html
There may be a good side to finding perchlorates as Chlorate-rich soil may help us find liquid water on Mars
Beautiful Mars
A possible briny mixture with magnesium chlorate salts might be found in places but there is likely to be others...For water, the triple point is found at 0.01 degrees Celsius (32 degrees Fahrenheit) and 6.12 millibar, or 0.6% of the atmospheric pressure at the Earth’s surface. Magnesium chlorate would be less likely to evaporate or freeze on Mars compared with water mixed with sodium or potassium chlorate.
In 2008, the Phoenix lander’s Thermal Evolved Gas Analyzer (TEGA), which was part of its on-board Wet Chemistry Lab, found perchlorates in soil samples from Mars’ north polar region, at concentrations of 0.4–0.6%. This encouraged scientists to re-analyze data from soil samples from the Viking lander missions, which took place in the 1970s.
The new analysis suggested that the soil found at Chryse and Utopia Planitiae by the Viking landers contained perchlorates at a concentration less than or equal to 0.1%. Then, in 2013, the Curiosity rover’s Sample Analysis at Mars (SAM)instrument found calcium perchlorate in soil samples from Rocknest, which is a spot within Gale Crater.
With polar area being higher than as you approach the equator is promissing as to finding just the right place with testing for less perchlorates that would be harmful to man.
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creating enough soil for agricultural...is not a very sensible
...
Probably hydroponics, using imported nutrient solution is the best way forward initially. Over time, it should be possible for the Mars colony to start producing its own nutrient solution using organic waste, human faeces and other material from the Mars regolith.
You can make nutrient solution from fertilizer powder and water. It's mostly water; you don't want to import water from Earth. But even that much fertilizer is not practical. And producing nutrient solution from Mars regolith means you have to process Mars soil anyway. Concentrating nutrients out of soil requires much more processing. So you have to process the same soil anyway, but instead of letting plants do the extraction themselves, you want to do it. That's a much bigger job.
Of course, the good thing about soil is that having created it, you can use it again and again as long as you treat it right and it makes a good choice if you are engaging in natural light farming.
Duh!
Mars soil vs regolith: Mars soil is loose unconsolidated regolith with soft hydrated hydrologically weathered minerals such as clay. To use geological terms, it's soil. To use agricultural terms, it isn't soil but is dirt. The term "regolith" was first coined to refer to the surface material of the Moon. That's nothing but igneous rock pulverized by billions of years meteorite and micrometeorite impacts. There's no sedimentary minerals, no hydrated minerals. By that definition, the loose unconsolidated material of Mars is not "regolith", it's dirt. When Mariner 4 first made a successful fly-by of Mars in 1965, it imaged craters, scientists thought it looked like the Moon. But minerals are quite different.
The thing is you overestimate the work involved in processing soil, and underestimate the work involved in making nutrient solution. Soda water can be made simply by putting clean water in a container with pressurized Mars atmosphere, leave it sit for several hours. That's all. Soak Mars dirt in soda water, wait while the carbonic acid does it's work. When done, rinse with clean water. Then treat the water with a catalyst to break-down perchlorate, then add the water solution back to the dirt. There, you have soil. Add ammonium nitrate granules for nitrogen fertilizer. You're done, soil ready to grow crops. And don't complain about work needed to make ammonium nitrate, because your hydroponic solution would need it anyway. This is a lot simpler than trying extract nutrients for hydroponic solutions.
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this is mars simply shovel it into the container that we are going to use inside the greenhouse and start to process it.
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Ok, sift out the rocks.
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You and I are on the same page to bring life to mars....
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There'll also need to be a starter culture of Earth earth, to get the right bacterial mix in the soil, and it'll need carbon added to it to.
Use what is abundant and build to last
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I'm encouraged that you indicate soil creation is not so difficult. That's good news.
I still think an early colony will have other priorities than 100% or even 50% agricultural self-sufficiency (e.g. achieving 90% industrial self-sufficiency, earning money through science experimentation, propellant production and exploration to name a few). But as soon as it moves up the chart, because of population pressure, I would be fully on board with soil creation.
louis wrote:creating enough soil for agricultural...is not a very sensible
...
Probably hydroponics, using imported nutrient solution is the best way forward initially. Over time, it should be possible for the Mars colony to start producing its own nutrient solution using organic waste, human faeces and other material from the Mars regolith.You can make nutrient solution from fertilizer powder and water. It's mostly water; you don't want to import water from Earth. But even that much fertilizer is not practical. And producing nutrient solution from Mars regolith means you have to process Mars soil anyway. Concentrating nutrients out of soil requires much more processing. So you have to process the same soil anyway, but instead of letting plants do the extraction themselves, you want to do it. That's a much bigger job.
louis wrote:Of course, the good thing about soil is that having created it, you can use it again and again as long as you treat it right and it makes a good choice if you are engaging in natural light farming.
Duh!
Mars soil vs regolith: Mars soil is loose unconsolidated regolith with soft hydrated hydrologically weathered minerals such as clay. To use geological terms, it's soil. To use agricultural terms, it isn't soil but is dirt. The term "regolith" was first coined to refer to the surface material of the Moon. That's nothing but igneous rock pulverized by billions of years meteorite and micrometeorite impacts. There's no sedimentary minerals, no hydrated minerals. By that definition, the loose unconsolidated material of Mars is not "regolith", it's dirt. When Mariner 4 first made a successful fly-by of Mars in 1965, it imaged craters, scientists thought it looked like the Moon. But minerals are quite different.
The thing is you overestimate the work involved in processing soil, and underestimate the work involved in making nutrient solution. Soda water can be made simply by putting clean water in a container with pressurized Mars atmosphere, leave it sit for several hours. That's all. Soak Mars dirt in soda water, wait while the carbonic acid does it's work. When done, rinse with clean water. Then treat the water with a catalyst to break-down perchlorate, then add the water solution back to the dirt. There, you have soil. Add ammonium nitrate granules for nitrogen fertilizer. You're done, soil ready to grow crops. And don't complain about work needed to make ammonium nitrate, because your hydroponic solution would need it anyway. This is a lot simpler than trying extract nutrients for hydroponic solutions.
Last edited by louis (2019-10-29 07:14:48)
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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Soil manufacture is something beyond the capabilities of a first mission, other than small experimental quantities. It could be accomplished by means of large Pfaudler or DeDeitrich chemical reactors on a large scale batch process, coupled with use of centrifuges for separation of processed soil from wash solutions. This is entirely predicated upon discovery of large and easily accessible water supply.
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Soil manufacture is something beyond the capabilities of a first mission...This is entirely predicated upon discovery of large and easily accessible water supply.
It's amazing how we keep going over the same issues again, and again, and again, and again...
Yes, Mars Direct was designed to bring stored food for the entire mission. The inflatable greenhouse was intended as an experiment. And yes, we need water. Should I post images from MRO's SHARAD instrument showing glaciers in the sides of canyons at mid-latitude? Or the frozen pack ice at 5° north latitude?
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Rob-
My post #22 wasn't meant to renew THAT part of this discussion! I was specifically aiming at the process BY WHICH we can succeed in later colonization efforts. There is available the necessary equipment to facilitate turning Mars dirt into agricultural soil. We need to consider how much dirt needs to be treated to make Martian agriculture more than an experiment. When I become involved is setting up chemical processes, I plan for absolute success ON A GRAND SCALE! Ideal apparatus for this would be 10,000 gallon Stainless steel, Type 304, stirred and bottom outlet Pfaudler reactors with plumbing into massive DeLaval chemical centrifuges. My plan would be capable of manufacturing TONS of soil per HOUR! In a continuous series of batches. This would be water-intensive, but not require too much energy input. Yeah, there would also be some "grunt work" involved, but the results justify the means and efforts made.
Last edited by Oldfart1939 (2019-10-29 18:08:43)
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Some on earth use the 16 rule for sizing everything from horse power to acreage while others have indicated that you could starve on 5 acres.
So build a small farm garden have and was discussed in he crop topics for purpose of an acre for size most plants need less than 6 inches of soil to root in while only a few need up to a foot to be able to grow into.
The big thing is to pick the foods to grow and create a planting schedule for timing the foods to eat for meals. This means you need to know just how fast they grow and the yield from the plot size that is planted. Utilize every square inch that you can with the initial planting so as to be able to stagger the crops.
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