7 ms·

Unless they are adding chemicals to the water before desalination (which I don't see mentioned anywhere), that sounds like the 'brine' is just ~1.5x concentrate

Unless they are adding chemicals to the water before desalination (which I don't see mentioned anywhere), that sounds like the 'brine' is just ~1.5x concentrated seawater, which will get diluted back again? What am I missing?

blunte 8y ago
The article said the brine has chlorine and copper (added, and remaining).
- ricardobeat 8y ago
  It says 'about 1.5 liters of liquid polluted with chlorine and copper are created', but doesn't explain if these are additives or some kind of byproduct.
  - deleted 8y ago
    [deleted]
dsfyu404ed 8y ago
Even if it's just extra salty it's still a local problem. You can't just dump it all in the ocean because it would still kill everything. You'd need to dump it out slowly or over a much wider area for the concentration not to be harmful. It's like a polluted river killing everything where it dumps out even if the amount of pollution is inconsequential overall.
- ricardobeat 8y ago
  Someone correct me if I'm wrong (not the best at math), but the ocean is massive. The entire amount of brine they mention (31.5 million cubic meters) fits in one 300m square cube. Even if you drop it in an enclosed 1km-wide area of seawater, it will barely increase concentration by 0.01%. It would take millenia for us to increase sea salinity by this method, and all that treated water is eventually coming back. Even if you took the total daily water consumption of the entire human race - 150l per person * 7 billion, or 1^12 liters, and made it extra salty, it is dwarfed by the total of 1.26^21 [mostly sea]water on earth. This would be harmless assuming we are not adding anything to the byproduct, which unfortunately seems to be the case according to the other comments.
  - SolaceQuantum 8y ago
    The concern is not ocean-level damage through the salt directly but in localized ecological system destruction. The mangrove forest encompases a tiny portion of the ocean overall but removing this forest affects a large portion of sealife. The creation of 'deadzones' through salinity will have knockoff effects elsewhere that cannot necessarily be predicted.
    - Retric 8y ago
      At worst these dead zones would be tiny. They could dilute the waste stream by dumping it into the local sewage system, but I don’t think that’s going to change much. It’s on the order of building a mall parking lot. Sure bad for the local ecosystem, but we have vastly larger issues.
      - sp332 8y ago
        It's going to be dumped near the shoreline, where sea life is very different from what is supported in the open ocean. If the shoreline is made uninhabitable, the marine life there might not have anywhere else to go.
        Retric 8y ago
        Near in this case would need to basicly be directly into. Actual desalination plants don’t do this. Further by parking lot I mean an actual parking lot. Dump it even 1000 feet from the shoreline and you would have trouble detecting the extra salt in the surf.
        WillPostForFood 8y ago
        There are over 7500km of shoreline in Saudi Arabia, so marine life can move along the coast away from the salt water outlets.
        SolaceQuantum 8y ago
        Shoreline is also highly variable and localized, and effects to the shoreline have staggering effects even if the region affected is small. I'd recommend looking at mangrove forests, coral reefs, and the mouths of rivers.
- deleted 8y ago
  [deleted]
- swebs 8y ago
  How about dumping it into a shallow pit and letting the water evaporate, creating new salt flats.
  - ryanmercer 8y ago
    >Saudi Arabia emits 31.5 million cubic meters of liquid effluent a day You'd need some massive pits and you'd have to displace way more than 31.5 million cubic meters of soil as it isn't all going to evaporate in a day. Ideally you'd want really shallow pools so you'd eat up an insane surface area. For some reference an Olympic sized swimming pool is about 2,500 cubic meters so you'd need 12,600 (pools) just to hold one day worth of the contaminated water. For a fun little compassion (that amuses me and might someone else) it is estimated that all of the silver ever mined adds up to about 166,375 cubic meters Source: https://www.usgs.gov/faqs/how-much-silver-has-been-found-world?qt-news_science_products=0#qt-news_science_products https://www.usgs.gov/faqs/how-much-silver-has-been-found-wor... And only about 8000 cubic meters of gold has been mined. Source: https://www.jmbullion.com/investing-guide/james/gold-supply/ https://www.jmbullion.com/investing-guide/james/gold-supply/ Edit: derpity-derp-derp fix
    - utexaspunk 8y ago
      Couldn't they just run a big pipe out into the middle of the desert and pump it there? Maybe they could create giant salt flats and extract rare earth elements from them, even...
    - z2 8y ago
      Wait. Do you mean a cube of silver|gold that's 55|20 meters on one side, as in the width of the cube and not its volume? As in 55^3 = 166,375 m^3 of silver, and 20^3 = 8000 m^3 of gold? That 5.36m diameter cube illustration representing a single year's gold production in the source is already 154 cubic meters.
    - itcmcgrath 8y ago
      A cube 55 meters on a side, not 55 cubic meters. That's a huge difference: 166K+ cubic meters
tomatotomato37 8y ago
It's from anti-fouling and general corrosion. Not sure what makes these plants special though since a population's regular water supply infrastructure would end up producing the same type of waste from pumps and what not.
cronix 8y ago
> which will get diluted back again Also raising the concentration of salts in the oceans, especially in the immediate area where they're dumping it back into the ocean in the gulf that has weak ocean currents (due to being a gulf). I can't imagine the wildlife will enjoy that much. It also makes it harder for future desalination, as it's having to desalinate an ever increasing percentage of salt since they just dump it back into the ocean. https://www.scientificamerican.com/article/desalination-breakthrough-saving-the-sea-from-salt/ https://www.scientificamerican.com/article/desalination-brea...

blunte 8y ago

The article said the brine has chlorine and copper (added, and remaining).

ricardobeat 8y ago
It says 'about 1.5 liters of liquid polluted with chlorine and copper are created', but doesn't explain if these are additives or some kind of byproduct.
- deleted 8y ago
  [deleted]

dsfyu404ed 8y ago

Even if it's just extra salty it's still a local problem. You can't just dump it all in the ocean because it would still kill everything. You'd need to dump it out slowly or over a much wider area for the concentration not to be harmful. It's like a polluted river killing everything where it dumps out even if the amount of pollution is inconsequential overall.

ricardobeat 8y ago
Someone correct me if I'm wrong (not the best at math), but the ocean is massive. The entire amount of brine they mention (31.5 million cubic meters) fits in one 300m square cube. Even if you drop it in an enclosed 1km-wide area of seawater, it will barely increase concentration by 0.01%. It would take millenia for us to increase sea salinity by this method, and all that treated water is eventually coming back. Even if you took the total daily water consumption of the entire human race - 150l per person * 7 billion, or 1^12 liters, and made it extra salty, it is dwarfed by the total of 1.26^21 [mostly sea]water on earth. This would be harmless assuming we are not adding anything to the byproduct, which unfortunately seems to be the case according to the other comments.
- SolaceQuantum 8y ago
  The concern is not ocean-level damage through the salt directly but in localized ecological system destruction. The mangrove forest encompases a tiny portion of the ocean overall but removing this forest affects a large portion of sealife. The creation of 'deadzones' through salinity will have knockoff effects elsewhere that cannot necessarily be predicted.
  - Retric 8y ago
    At worst these dead zones would be tiny. They could dilute the waste stream by dumping it into the local sewage system, but I don’t think that’s going to change much. It’s on the order of building a mall parking lot. Sure bad for the local ecosystem, but we have vastly larger issues.
    - sp332 8y ago
      It's going to be dumped near the shoreline, where sea life is very different from what is supported in the open ocean. If the shoreline is made uninhabitable, the marine life there might not have anywhere else to go.
      - Retric 8y ago
        Near in this case would need to basicly be directly into. Actual desalination plants don’t do this. Further by parking lot I mean an actual parking lot. Dump it even 1000 feet from the shoreline and you would have trouble detecting the extra salt in the surf.
      - WillPostForFood 8y ago
        There are over 7500km of shoreline in Saudi Arabia, so marine life can move along the coast away from the salt water outlets.
        SolaceQuantum 8y ago
        Shoreline is also highly variable and localized, and effects to the shoreline have staggering effects even if the region affected is small. I'd recommend looking at mangrove forests, coral reefs, and the mouths of rivers.
deleted 8y ago
[deleted]
swebs 8y ago
How about dumping it into a shallow pit and letting the water evaporate, creating new salt flats.
- ryanmercer 8y ago
  >Saudi Arabia emits 31.5 million cubic meters of liquid effluent a day You'd need some massive pits and you'd have to displace way more than 31.5 million cubic meters of soil as it isn't all going to evaporate in a day. Ideally you'd want really shallow pools so you'd eat up an insane surface area. For some reference an Olympic sized swimming pool is about 2,500 cubic meters so you'd need 12,600 (pools) just to hold one day worth of the contaminated water. For a fun little compassion (that amuses me and might someone else) it is estimated that all of the silver ever mined adds up to about 166,375 cubic meters Source: https://www.usgs.gov/faqs/how-much-silver-has-been-found-world?qt-news_science_products=0#qt-news_science_products https://www.usgs.gov/faqs/how-much-silver-has-been-found-wor... And only about 8000 cubic meters of gold has been mined. Source: https://www.jmbullion.com/investing-guide/james/gold-supply/ https://www.jmbullion.com/investing-guide/james/gold-supply/ Edit: derpity-derp-derp fix
  - utexaspunk 8y ago
    Couldn't they just run a big pipe out into the middle of the desert and pump it there? Maybe they could create giant salt flats and extract rare earth elements from them, even...
  - z2 8y ago
    Wait. Do you mean a cube of silver|gold that's 55|20 meters on one side, as in the width of the cube and not its volume? As in 55^3 = 166,375 m^3 of silver, and 20^3 = 8000 m^3 of gold? That 5.36m diameter cube illustration representing a single year's gold production in the source is already 154 cubic meters.
  - itcmcgrath 8y ago
    A cube 55 meters on a side, not 55 cubic meters. That's a huge difference: 166K+ cubic meters

tomatotomato37 8y ago

It's from anti-fouling and general corrosion. Not sure what makes these plants special though since a population's regular water supply infrastructure would end up producing the same type of waste from pumps and what not.

cronix 8y ago

> which will get diluted back again Also raising the concentration of salts in the oceans, especially in the immediate area where they're dumping it back into the ocean in the gulf that has weak ocean currents (due to being a gulf). I can't imagine the wildlife will enjoy that much. It also makes it harder for future desalination, as it's having to desalinate an ever increasing percentage of salt since they just dump it back into the ocean. https://www.scientificamerican.com/article/desalination-breakthrough-saving-the-sea-from-salt/ https://www.scientificamerican.com/article/desalination-brea...