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The Dirty Truth About Turning Seawater into Drinking Water

earther.gizmodo.com

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Re: The Dirty Truth About Turning Seawater into Drinking Water

#41

Post by endorphone »

Jeff_Brown wrote: post #39
endorphone wrote: post #30

Earlier quoted context omitted.

Just to be clear, "brine" isn't "salty water." It mostly is, and the additional chemicals they mention are already in the sea water, not that were added somehow in the process. It's just concentrated. That it's concentrated is a problem, obviously -- very high-saline water (e.g. brine) and concentrated toxins are a problem, and would cause environmental problems if just dumped. The most common way to deal with brine…

Diluting it with ... fresh water?

You churn it with a large volume of sea water and then discharge it when the salinity is only acceptably above the natural amount. I believe France limits it to 10% above the natural salinity.

e.g. take 3 gallons of sea water and extract 1 gallon of fresh water. You have 2 gallons of +50% salinity brine. Churn it with 8 gallons of seawater and you're back to +10% salinity. Wash it out into the ocean.

Re: The Dirty Truth About Turning Seawater into Drinking Water

#42

Post by csense »

Sure, the high salt concentration kills sea life for a couple hundred meters around where the waste comes out, but compared to the total size of the ocean, I'd imagine the affected area would be TINY. Once you get to a larger area it'd be totally diluted by the normal salinity seawater.

Why don't you just build a pipeline to put the dead spot a couple miles away from shore, far away from economically important beaches, fisheries and reefs?

Maybe have an additional pump to send fresh seawater into the areas of highest concentration, basically set up a countercurrent exchange gradient.

I'm sure there are trivial, low-cost engineering solutions to this problem.

Re: The Dirty Truth About Turning Seawater into Drinking Water

#44

Post by jpfed »

nickthemagicman wrote: post #27
arkades wrote: post #6

Just to be clear, "brine" isn't "salty water." > This untreated salt water can’t just hang around in ponds—or, in worst-case scenarios, go into oceans or sewers. Disposal depends on geography, but typically the waste does go into oceans or sewers, if not injected into wells or kept in evaporation ponds. The high concentrations of salt, as well as chemicals like copper and chlorine, can make it toxic to marine life. >…

Is there any use for it at all?

It's possible to use salt water and limestone to capture CO2; I wonder whether brine could be used for this purpose.

Re: The Dirty Truth About Turning Seawater into Drinking Water

#46

Post by Arn_Thor »

Tepix wrote: post #45

I see this as an opportunity. Before you dilute the brine with sea water and pump it back into the ocean, ideally you remove the microplastics and perhaps some other problematic substances and thus clean up the ocean.

where's the money in that?

/depressed sarcasm/

Re: The Dirty Truth About Turning Seawater into Drinking Water

#47

Post by damon_c »

CamTin wrote: post #5
bryanlarsen wrote: post #2

The desalinated water will end up back in the oceans eventually, so should the brine. Of course you can't just dump it back in directly, but if diluted and released responsibly, the ocean is the right place for the brine.

What do you dilute it with? You just spent a bunch of time and energy seperating water from it. I guess we should ship/pipe the brine to wastewater treatment facilities, and mix it with the treated waste before discharging it back into the ocean/river?

Put it in big leaky boats that drive around in 1000km radius circles?

Re: The Dirty Truth About Turning Seawater into Drinking Water

#48

Post by ndnxhs »

csense wrote: post #42

Sure, the high salt concentration kills sea life for a couple hundred meters around where the waste comes out, but compared to the total size of the ocean, I'd imagine the affected area would be TINY. Once you get to a larger area it'd be totally diluted by the normal salinity seawater. Why don't you just build a pipeline to put the dead spot a couple miles away from shore, far away from economically important beache…

Or just mix it with more sea water before releasing it.

Re: The Dirty Truth About Turning Seawater into Drinking Water

#50

Post by kiriakasis »

sunstone wrote: post #38
arkades wrote: post #6

Just to be clear, "brine" isn't "salty water." > This untreated salt water can’t just hang around in ponds—or, in worst-case scenarios, go into oceans or sewers. Disposal depends on geography, but typically the waste does go into oceans or sewers, if not injected into wells or kept in evaporation ponds. The high concentrations of salt, as well as chemicals like copper and chlorine, can make it toxic to marine life. >…

Yes, just like exhaled breath is a waste product full of C02 and containing very little oxygen. If other people had to breath that they would become very sick or even die.

Actual question, how many time can air be breathed? I think you can live on second-hand breath.
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