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  • Some plants are totally metaland I'm not just talking about venus fly traps.

  • There are plants that literally ooze metal!

  • And we're farming them!

  • But first, we gotta back it up a little bit.

  • In the ground beneath our feet, there can be all kinds of different metals.

  • Not in the form you and I might picture them, like in a can or in your car, but in a much

  • more unrefined, elemental form.

  • And turns out, some plants have evolved to absorb lots of metal from these soils, through

  • their roots.

  • These helpful superstars are called hyperaccumulators, and there are lots of different kinds.

  • After sucking up all that tasty metal, hyperaccumulating plants do just thatthey accumulate that

  • metal in their bodies.

  • (If you can call them that.

  • Do plants have bodies?

  • Whatever, you get the point.)

  • Now the metal is inside them, it's literally running through their vascular structures

  • in their sap, or even their shoots, seeds, and leaves.

  • So now, we can extract it from the plant, which has so handily brought it all together

  • for us.

  • A group of researchers working on a small trial farm on the Malaysian side of the island of Borneo

  • is already trying this with a plant that accumulates nickel.

  • Every six to twelve months or so, the farmer can harvest about this length of metal-filled

  • plant tissue, and through purification, then have all this metal, no mining required.

  • Nickel in particular is an essential component of stainless steel, like what you might see in your kitchen,

  • and we're seeing increasing demand for both it and its derivatives

  • for things like electric car batteries and even

  • your cell phone.

  • But mining it - just like mining other heavy metals and rare earth elements - is extremely

  • destructive.

  • Not only because you're literally cutting open the earth, but because you're leaving

  • behind some really intense chemical pollution as you refine it, too.

  • The process we humans have traditionally used to extract the metal from its raw form in

  • the ground is calledsmelting,” and it involves lots of energy-intensive heating

  • and melting, plus purifying chemicals and lots of waste products.

  • So, as our world's boundless appetite for things like cobalt, zinc, and other heavy

  • metals continues to grow, we're seeing a serious environmental impact.

  • That comes in the form of water, soil and air pollution - not only from smelting's

  • byproducts, but also from the metal itself, which can be really poisonous when inhaled

  • or ingested.

  • So, being able to farm these metals, instead?

  • Yes, please.

  • The plants are basically natural, solar-powered smelters: they do the whole thing for us in

  • a totally self-contained way.

  • And this concept is calledbioharvesting,” or more specifically, “phytomining.”

  • Which basically means we're farming metal, which just sounds way too cool for this reality.

  • But that's not all.

  • Because remember that pollution I was just talking about?

  • In addition to being a sustainable source of heavy metals and maybe eventually rare

  • earth elements, they can also be used to clean up heavy metal pollution.

  • Another research group has been studying copper- and zinc- accumulating plants.

  • They've shown that plants - specifically Brassica juncea, a kind of mustard plant and

  • Sedum alfredii, a common Asian herb, could uptake heavy metals

  • from a polluted copper-zinc mine.

  • This helped clean up the site, a process called phytoremediation.

  • Then the team was able to process those plant tissues and use the bio-accumulated metal

  • to make carbon nanotubes and carbon zinc-oxide nanoparticles, both of which can be used to

  • advance all kinds of exciting electronics and energy technologies.

  • So, not only did you clean up the pollution, but you then were able to still use that material

  • instead of having to find a way of safely disposing of it, and you made

  • something really useful out of it.

  • It kinda feels like we could really be on our way to getting this recycling thing down, you guys.

  • Exciting as it is, all of this is still in its beginning stages.

  • Scientists are working hard on optimizing growing techniques and understanding ideal

  • growth and accumulation conditions to make this phytomining thing a really strong competitor

  • to the existing methods.

  • They even say with further development of the science, they think this process could

  • expand all over the globe... really changing what we mean when we say a "grassroots solution."

  • One last fact: scientists think that it may have been helpful for hyperaccumulators to

  • evolve the ability to store these metals in their tissues so they would be toxic to predators.

  • Pretty cool.

  • If you want more surprising melding of nature and tech

  • check out my other video on graphene-enhanced

  • mushrooms over here.

  • And keep coming back to Seeker for all of your news on botanical advancements.

  • As always, thanks so much for watching, and I'll see you next time!

Some plants are totally metaland I'm not just talking about venus fly traps.


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B1 中級

植物からの金属の養殖は、持続可能な技術の未来になるかもしれない (Farming Metal From Plants Could Be the Future of Sustainable Tech)

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    Summer に公開 2021 年 01 月 14 日