Water

[Larry Caldwell]

I ran across this article this morning. Why was it not headlines in every coastal newspaper in the US? Desalination may become the default fresh water source on coastlines.

Fluorine nanostructures can desalinate water 2,400 times faster than carbon nanotubes

The method is "several thousand times faster" than systems currently available on the market.

interestingengineering.com

 

[leonz]

If we ever get to the point where we start using small thorium salt reactors for power
we will be able to distill as much or more sea water as an aircraft carrier is able to.

The US Navy distilled 100,000 plus gallons a day for use by TEPCO at Fukushima
to cool the reactor piles when their reactors failed after the earthquake.

They pumped the distilled water from the aircraft carrier to barges and pumped it from the
barges to shore to cool down the atomic piles. If my memory is right they used helicopters and
hoisted water bags up over the reactors to dump water on them as they could not use sea water
to cool the damaged atomic piles.

 

[Larry Caldwell]

100,000 gallons is literally a drop in the bucket. Practical desalination needs to produce 100,000,000 gallons a day.

 

[ponytug]

Fun paper, is 't it?

Missing in the details is that those particular molecules are neither stable, nor usable in a membrane with any sort of stability. So, a light bulb idea, with lots of TBD engineering and chemistry to come.

However, the paper was a wake up call to reverse osmosis membrane designers that the way nature does it, with narrow, hydrophobic channels, restructures water and enables much higher water flow rates.

What the observation doesn't change is the energy required to separate pure water from brackish, salt, or mineral laden waters.

All the best,

Peter

 

[Larry Caldwell]

How do you make a fluorine molecule unstable? It's not like it's going to oxidize. The big advantage of the new tech is that it runs on a fraction of the energy required for RO.

 

[beowulf]

Wow, that is 'nano'. Interesting concept - and needed.

 

[deserteagle71]

I keep reading about sea levels rising to the point where coastal communities may be flooded. I also read about (and am experiencing) the severe drought in the western US. So...I hope this desalinization process is perfected soon. We could lower sea levels and get us living in the dry southwest some much-needed water!

 

[grsthegreat]

What do they do with the salt from the water? Pump it back into ocean until entire ocean becomes the great salt lake?

 

[deserteagle71]

What do they do with the salt from the water? Pump it back into ocean until entire ocean becomes the great salt lake?

Put it in a container and sell it to you as table salt? "Sea salt"?

 

[duffer]

What do they do with the salt from the water? Pump it back into ocean until entire ocean becomes the great salt lake?

Use it export it to countries that need it. It's just a commodity that is needed around the world.

Aruba has a large desalination plant and exports all of the salt they create.

 

[Larry Caldwell]

I keep reading about sea levels rising to the point where coastal communities may be flooded. I also read about (and am experiencing) the severe drought in the western US. So...I hope this desalinization process is perfected soon. We could lower sea levels and get us living in the dry southwest some much-needed water!

If your house floods during hurricanes, sell out and move. The places that will get wet are the Gulf Coast and Atlantic. Florida, in particular, is going to mostly disappear. However, if you have a typical rocky coast where you have to climb down a 40' cliff to get to the beach you have nothing to worry about. Desalination will have no effect on sea level. I doubt it will help the SW much either, though low altitude users like LA might sell their water rights on the Colorado.

 

[ruffdog]

A young noob engineer asked me back in 2007 what I would recommend them to specialize in. I told them to study desalination because good clean drinking water was going to become rare in the future. Little did I know.....

 

[ponytug]

How do you make a fluorine molecule unstable? It's not like it's going to oxidize. The big advantage of the new tech is that it runs on a fraction of the energy required for RO.

The way they made the pores was like stacking washers. The inside of the washer is lined with fluorine atoms, but the washers aren't connected together strongly, nor are they fastened to the surrounding membrane which was made of mobile (fluid) lipids that are hydrophobic at one end and hydrophilic on the other. Lipid membranes enclose our cells, but they are neither strong, or durable when not protected by skin.
Contrary to the claims, it doesn't change the energy of undoing the entropy of mixing, though it does reduce a little the amount of energy required for RO. Not to a fraction unfortunately.

What do they do with the salt from the water? Pump it back into ocean until entire ocean becomes the great salt lake?

Reverse osmosis generates two streams of water, one reduced in dissolved ions and one enhanced. If you start with seawater, then one stream gets quite salty and the brine disposal is always back to the ocean in one way or another. Depending on the location, it may be injected into beach sand, run through pipes with holes to mix and dilute the concentrated brine, or dumped into the depths. There are lots of environmental concerns about what may be the lowest impact method, and "optimal" would appear to vary depending on local conditions of water temperature, offshore currents and topology.

Due to the energy cost, reverse osmosis water is much, much more expensive than other sources. There are lots of smart folks trying to come up with a better mousetrap, but at the end of the day, even just undoing the entropy of mixing is a lot of energy.

All the best,

Peter

 

[Hay Dude]

If your house floods during hurricanes, sell out and move. The places that will get wet are the Gulf Coast and Atlantic. Florida, in particular, is going to mostly disappear. However, if you have a typical rocky coast where you have to climb down a 40' cliff to get to the beach you have nothing to worry about. Desalination will have no effect on sea level. I doubt it will help the SW much either, though low altitude users like LA might sell their water rights on the Colorado.

Based on what? Watching old Al Gore videos?

 

[Oaktree]

Based on what? Watching old Al Gore videos?

Well, considering the fact that much of Florida is only tens of feet above sea level, it's not going to take much of a rise to flood it. Even an inland city like Orlando is only 80' elevation.
But you already knew this.

 

[Hay Dude]

Well, considering the fact that much of Florida is only tens of feet above sea level, it's not going to take much of a rise to flood it. Even an inland city like Orlando is only 80' elevation.
But you already knew this.

But that hasn’t happened. And the world isn’t going to end in 9 years, either.
10’ above sea level is more at risk for bad storms than claimed rising sea levels.
Sea levels can drop, too.

 

[2LaneCruzer]

Rented a house and stayed a week in St. Thomas USVI a few years back; found out a few things about island life. Number one, in this location the only available water was rain water, so they had a collection system that stored the water in a tank in the basement, and a purification system. You had to be very conserving on water, and careful about not taxing your septic system. Their motto was "If it's yellow, let it mellow. If it's brown, flush it down."

#2, the island had had to import oil from Venezuela to make electricity, so the bill for this house ran over $1200 per month. I did see a few of the giant windchargers there but the didn't improve the view any. Gasoline was very expensive.

Once you do the sightseeing thing, spend a few days at the beach and spend a hundred bucks a night eating out, there wasn't much to do. Roads were narrow, winding, mountainous and slick, besides having to drive on the left hand side of the street. Grocery stores smelled like fish.

One good thing if you want to look at it that way; liquor, especially rum, is very cheap. We were cautioned that when you order a drink, be careful...the mixer is more expensive than the alcohol, so it will be strong!

I will say though, one of the most breathtaking and beautiful places I have ever been.

 

[Oaktree]

Their motto was "If it's yellow, let it mellow. If it's brown, flush it down."

Maybe TMI, but that's how we were brought up as kids. I know people today with dug wells that still do this.

 

[dmccarty]

One of the revolutionary devices created for people traveling the world by boat is the reverse osmosis water maker, aka, the magic equipment that turns salt water into drinking water.

One company has a patent for a low power usage pump but there are other companies using pumps, it is just a pump, that gets the job done, but uses more energy. The advantage of the less efficient pump is that you are more likely to find a replacement pump locally compared to waiting for the proprietary pump to arrive by mail.

We could generate all of the fresh water we need for the house from some solar panels and one of the water makers.

One could water a decent sized garden once a week without too much problem.

Later,
Dan

 

[Jstpssng]

Maybe TMI, but that's how we were brought up as kids. I know people today with dug wells that still do this.

3 tinkles make a royal flush! Year ago I used to sublet rooms to coworkers in the apartment I was renting. The last two guys couldn't get over that I didn't flush every time I used the toilet.