Posted on 07/09/2021 1:41:29 PM PDT by blam
Could the holy grail of turning salt water to drinkable water finally be upon us?
A new report from Interesting Engineering seems to suggest that could be the case – detailing a new nanofiber membrane, developed by Yunchul Woo and his team at the Korea Institute of Civil Engineering and Building Technology, that appears to be “stable in the long term” for desalinization. And it can be done “in minutes”, the report says.
Membranes had been used in the past, but there is often a challenge in keeping them dry for long periods of time. When they become wet, their filtration characteristics become ineffective and large amounts of salt can pass through.
Woo’s team has created a membrane “made of nanofibres that have been fabricated into a three-dimensional hierarchical structure” by using a technology called “electrospinning”. This new membrane is said to be highly water repellant.
Water from one side is heated and allows water vapor to pass through the membrane, which is then condensed on the other side. The process is called membrane distillation.
“Since the salt particles are not converted to the gaseous state, they are left out on one side of the membrane, giving highly purified water on the other side,” the report says.
It also notes that the researchers used silica aerogel in their membrane fabrication process.
Upon testing the technology for 30 days continuously, they found the membrane filtered out 99.9% of salt without wetting problems.
Desalinization is the obvious answer to the global issue of over 785 million people lacking clean drinking water. Up until now, scientists have been unable to figure out a quick, cost-efficient and effective way to turn salt water into drinkable water.
Fresh water only accounts for 2.5% of the total water available on Earth, the report notes.
The latent heat of vaporization does not change regardless of temperature the water is when it goes to a vapor state.
I suspect we are missing something that the article does not explain.
But boiling water takes a lot of energy.
Dump it back into the ocean. It’s not like they are making it saltier.
“All I said was that they may add some heat but evidently it was a lot less than required to bring it to a boil.”
You forgot you made this false statement!
“I take it you aren’t aware that water evaporates despite the dreaded “latent heat of vaporization?””
“Put a dish of water on your kitchen table for a few days and get back to me.”
Now measure the change in temperature.
If a headline asks a yes/no question, the answer is ALWAYS “no”.
Check this curve for water:
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You're on a device connected to the internet. Was it arrogance, laziness or stupidity that kept you from checking the veracity of your dumb@$$3d statement?
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Desalination - USGS
Search domain usgs.gov:
https://www.usgs.gov/special-topic/water-science-school/science/desalinationDistillation desalination is one of mankind's earliest forms of water treatment, and it is still a popular treatment solution throughout the world today. In ancient times, many civilizations used this process on their ships to convert sea water into drinking water.
I have read that Great Britain has had a reward for anyone who can turn salt water into fresh water at a very, VERY low cost. So far no one has collected it.
Wonder if this will be it.
Obviously, dumping huge amounts of sludge into a small area is terrible idea. I’m speaking more in terms of a long-strategy. Unless the sea levels are actually dropping, returning the residue should be enviroentally sound if done correctly. That is, unless something external is actually being added during the desalinization process.
Why would their be brine? Run the brine through another filtration system, and keep running through another and another until you eventually get salt
“The problem still remains of disposing of the slurry of salt and other minerals. Currently most desalination plants return the sludgy, salty leftovers to the water supply, which is highly destructive of the environment.”
That is an old environmentalist bromide used as an argument against desalination plants. The obvious solution is to dilute the filtered material before returning it to the ocean.
The following is from the Tampa Bay desalination plant website.
“At full capacity, the RO process leaves about 19 mgd of twice-as-salty seawater behind which is returned to Big Bend’s cooling water stream and blended with up to 1.4 billion gallons of cooling water, achieving a blending ratio of up to 70-to-1. At this point before entering and mixing with any bay water, the salinity is already only 1.0 to 1.5 percent higher, on average, than water from Tampa Bay. This slight increase falls within Tampa Bay’s normal, seasonal fluctuations in salinity.
The cooling water mixture moves through a discharge canal, blending with more seawater, diluting the discharge even further. By the time the discharged water reaches Tampa Bay, its salinity is nearly the same as the Bay’s. And, the large volume of water that naturally flows in and out of Tampa Bay near Big Bend provides more dilution, preventing any long-term build-up of salinity in the bay.
Tampa Bay Water’s comprehensive hydrobiological monitoring program collects thousands of samples including continuous salinity measurements every 15 minutes near the desalination facility. This and other water quality monitoring since 2003 shows no measurable salinity changes in Tampa Bay related to plant production.”
https://www.tampabaywater.org/tampa-bay-seawater-desalination
This graph assumes the fluid is at the temperature indicate by the x axis already before adding the additional heat. So in the process you must include the energy needed to get to that temperature.
Also, 650 K is 377C or 710F; way higher than 210F for sea level boiling.
There are no free lunches in physics.
I have a BS in chemistry. This is first semester chemistry stuff. It’s not even college chemistry. Water evaporates, even ocean water.
Why don’t you answer my question instead of posting a phase diagram that you obviously don’t even understand?
There ya go again....ruining pipe dreams by bringing real science into the conversation. ;-)
To Z or not to Z ... apparently, it is an unanswerable question.
https://wikidiff.com/desalinization/desalination
Read the article and read my comment. Read both slowly. Then apply all of your reading comprehension, if you have any.
I await your apology for your incredible rudeness. I think you must have taken a wrong turn — the DU is that way —>
“Here’s a good article from Haaretz about growing concerns. At least one plant has been shut down due to its effect on the local environment.”
From what I gather Haaretz is a fairly liberal and greenish paper, so they are bound to play up “environmental concerns”.
I’m curious though, now that they’ve shut down one of the desal plant, how are going to make up for that lost source of water in a country whose population is steadily growing?
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