Engineers at MIT and in China are aiming to turn seawater into drinking water with a completely passive device that is inspired by the ocean, and powered by the sun.
In a paper appearing today in the journal Joule, the team outlines the design for a new solar desalination system that takes in saltwater and heats it with natural sunlight.
The researchers estimate that if the system is scaled up to the size of a small suitcase, it could produce about 4 to 6 liters of drinking water per hour and last several years before requiring replacement parts. At this scale and performance, the system could produce drinking water at a rate and price that is cheaper than tap water.
Don’t you just dump it back in the sea? Diluting should make this a minor issue right?
That’s what I always thought, but the local effects of hypersalinated water can be terrible for any nearby life
This is mostly a scale dependent issue. The size of this unit means it’s probably not a concern unless you ended up making thousands of them.
While true, I consider the issue very minor compared to getting people clean drinking water. There are no perfect solutions in society. Just a series of trade-offs, maximising benefits and minimising costs.
Yeah, that coastal community probably didn’t need any fish.
Large coastal communities don’t just go down to the local jetty and cast hooks into the water by the shore. Commercial fishing is done by large ships out in the ocean, far away from the cities.
You probably wouldn’t want to fish near a city’s sewer outflows anyway.
Depends on what you mean by far away and what kind of fish you’re talking about. Big fish like tuna are often caught far out at sea, but they’re also caught by the same small boats that do charter fishing an hour or two out from the shore. There’s plenty of inshore fishing that would be at risk, especially in bays where the salt would be less easily dispersed. I used to work at a fish market, and offhand I can think of multiple fishing industries that would be put at risk by carelessly dumping salt back in the ocean. The majority of shellfish, for example, is caught within sight of the beach. I don’t know if it’s still the case, but there used to be a ton of fishing done in Boston Harbor, and I’ve heard stories of crates of lobsters being opened only to find the lobsters carrying pieces of bodies dumped by the mob off the docks and into the harbor.
i consider 🤣 ehm ehm … I consider! I CONSIDER 😁
who the hell cares about what i consider? upvote this if you don’t give a shit about my considerations 😉
Thats the big ecological question. If we do this at scale, we’ll be releasing more briny water back into the sea than we take. Over time on industrial scales, what will this do to the oceans? Is the increased salinity negligible, even at large scales? Or will it cause marine wildlife to die out?
Think of it this way. Burning a pile of wood generates CO2. So first burning a bunch of gas or coal. A couple campfires won’t make a dent on the atmospheric composition. It’s only when we go this en masse and at industrial scales that we add appreciable CO2 to the atmosphere and cause global warming.
The ideal way to handle desalination would be for us to use the salt that’s produced, so the concentration in the ocean remains unchanged with respect to desalination.
But the water is all being returned to the ocean rather quickly. It’s not quite the same with CO2.
There’s some localized issues to deal with, but it’s not going to be a global salinity increase as we aren’t changing the form of the water and storing it, like the polar ice does.
So in fact, the ocean should already be desalinating slightly from the melting ice caps.
I thought about the ice caps, yeah. It’s just something that warrants long term monitoring and observation.