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A way to make water potable using carbon dioxide

economist.com

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Re: A way to make water potable using carbon dioxide

#21

Post by T-Winsnes »

mchannon wrote: post #16

Is this a breakthrough? Sure. But it's probably not a panacea. * Getting actual salt particles out of flows of water is not what their experiment accomplished. They got larger particulates out of the water. The latter is quite easy to do, and the former quite difficult. * Ionic charge is a very powerful driving force when what you're trying to move has a directionality to it, like a magnet picking up iron filings. Th…

Desalinating water is a different problem, with a different solution.

Problem this is looking to solve is cleaning up fresh water that is contaminated, which is in itself a large problem in poorer areas.

Re: A way to make water potable using carbon dioxide

#23

Post by doorley »

Sounds like a promising piece of technology. What I'm more impressed with, though, is the scientific journalism.

It's balanced, accurate, accessible, representative, and leaves out the hyperbole. I would pay for science journalism that read like this. Even better if it came with some biased, inflammatory, hyperbolic editorials on the side.

Re: A way to make water potable using carbon dioxide

#25

Post by askvictor »

Sunlight (specifically, UV radiation) does a pretty good job of killing pathogens: http://www.sodis.ch/methode/index_EN . Though it doesn't remove any non-biological contaminants; this one might be better at that.

But if it needs an industrial process to do this anyway, is this one significantly cheaper/easier than what's used in the developed world?

Re: A way to make water potable using carbon dioxide

#27

Post by PhantomGremlin »

doorley wrote: post #23

Sounds like a promising piece of technology. What I'm more impressed with, though, is the scientific journalism. It's balanced, accurate, accessible, representative, and leaves out the hyperbole. I would pay for science journalism that read like this. Even better if it came with some biased, inflammatory, hyperbolic editorials on the side.

What I'm more impressed with, though, is the scientific journalism.

Actually I was disappointed with the article.

The image at top shows two output streams: waste, and filtered water. I was expecting an explanation of this while reading the article. But as I read the words, the build-up wasn't matching the image.

Finally we come to: In a working system it would simply be a question of splitting the water stream into three as it left the processor, with the two outer branches being recycled and the inner one tapped and piped to consumers.

So, no, pretty sloppy.

Re: A way to make water potable using carbon dioxide

#28

Post by URSpider94 »

ams6110 wrote: post #17
ChuckMcM wrote: post #15

Earlier quoted context omitted.

I read that, but noted it suffers from 'scientist' blindness. These industrial processes, that are producing CO2 in large quantities, don't have an economical way to capture and cleanse that CO2 to allow for then shipping and selling it (or giving it) to this guy to clean water with it. If they could capture the CO2 they could already resell it economically as there are lots of uses for it. There was some work in 201…

What is the current process for producing "pure" CO2 gas for sale e.g. as dry ice, or for use in food/beverage or for other industrial purposes? Unlike e.g. nitrogen or oxygen, concentrating it out of the atmosphere would seem to be inefficient as it's only roughly 0.04%.

It's typically captured either from processes that make ammonia or hydrogen from methane (with CO2 being the only major byproduct), or by capturing the output from large-scale fermentation.

Source: http://www.uigi.com/carbondioxide.html

Re: A way to make water potable using carbon dioxide

#29

Post by URSpider94 »

ChuckMcM wrote: post #15
mhb wrote: post #14

Earlier quoted context omitted.

As to the necessary CO2, he imagines this would come from power stations and other industrial processes, such as cement-making, that produce the gas in large quantities as exhaust. This would restrict diffusiophoretic water plants to industrial cities—but, since such cities are huge sources of demand, that is hardly a problem.

I read that, but noted it suffers from 'scientist' blindness. These industrial processes, that are producing CO2 in large quantities, don't have an economical way to capture and cleanse that CO2 to allow for then shipping and selling it (or giving it) to this guy to clean water with it. If they could capture the CO2 they could already resell it economically as there are lots of uses for it. There was some work in 201…

True, CO2 capture from power plants and cement kilns is not yet reality.

That said, this process should work (if perhaps less efficiently) with less pure streams, since it should just depend on the partial pressure of CO2. Other gases like oxygen and water vapor should just be spectators in the process.

Re: A way to make water potable using carbon dioxide

#30

Post by jessaustin »

sintaxi wrote: post #22

You can make virtually any water source potable by boiling it. It so happens hot water has other useful purposes as well so why are we not showing those 1.8B people how to efficiently boil water? What am I not getting?

If you're boiling in some sort of still, sure, that will remove impurities, but those aren't common household items. Boiling a pot over a heat source will only kill bacteria; it won't remove impurities.
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