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Earth Technology

Repurposed: Ground Circuit Board Waste Can Clean Up Toxic Metals 33

ckwu writes "Researchers in Hong Kong have found a beneficial new use for the electronic waste from discarded cell phones, computers, and other gadgets. Ground up into a powder, printed circuit boards from these products could sponge up another type of pollution — toxic heavy metals in water. The researchers processed the nonmetallic fraction of waste circuit boards into a powder and found that it adsorbed metals like copper, lead, and zinc more efficiently than commercially available industrial adsorbents."
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Repurposed: Ground Circuit Board Waste Can Clean Up Toxic Metals

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  • by Kaenneth ( 82978 ) on Thursday August 01, 2013 @03:59PM (#44450525) Journal

    When Winter comes, the Gorillas will all freeze to death.

    • by HairyNevus ( 992803 ) <hairynevus@gm a i l . com> on Thursday August 01, 2013 @05:18PM (#44451283)
      For those scratching their heads:

      Skinner: ahh, but as it turns out the lizards where a god send since they've eaten all the pigeons.
      Lisa: Isn't that a little short sighted, what happens when where up to our ears with lizards?
      Skinner: Ah, well we shall simply release wave after wave of Chinese needles snakes.
      Lisa: then what about the snakes?
      Skinner: We simply import gorillas who will eat all the snakes.
      Lisa: Well what happens when we're up to our ears in gorilla's!
      Skinner: Ah that's the beauty of the thing, come winter the gorillas will freeze to death.

  • by kermidge ( 2221646 ) on Thursday August 01, 2013 @04:35PM (#44450859) Journal

    This is good tech stuff, for real-world use and valid "news for nerds, stuff that matters" - oops, we don't do that here anymore. It's one of the ways tech is supposed to work.

    Somebody had a thought, "I wonder..." or "What if..." and tested it.
    It worked; in fact, it worked very well. The need is not restricted to China, either.

    What's not to like? Where's the applause?

    • by slew ( 2918 ) on Thursday August 01, 2013 @05:09PM (#44451187)

      FWIW, it's not as if non-metallic recycled parts of circuit boards aren't in wide use today.

      The groundup non-metalic parts of circuit boards are used in plastic lumber, insulating concrete, asphault, and as a structural filler for some composite materials which are used for various types of products from furniture, to lunch trays and picture frames. Generally this pcb-waste-resin composite material is considered a high-quality replacement for wood-plastic material resulting in material that handle better bending stresses.

      The use of this in pulverized power form after treatment with KOH as heavy metal adsorber/filter is perhaps interesting/novel, but as stated in the article...

      Although the boards can become effective adsorbents, he says the method for making the materials may not be as energy efficient and cost effective as for other adsorbents, such as granular ferric hydroxide, because of all the processing steps needed to produce the treated powder.

      And since there are many other current uses for the waste circuit board material that require less energy and processing steps, it's not clear that this result is anything other than a novelty result...

      • Thanks for the clarification and info on other, more energy-efficient uses for the material - I hadn't thought to look into it - my bad. I like the way that people are finding more ways to use things that otherwise would be sent to the dump. (I recall from the late 70's a push to look into ways to scavenge and re-use stuff for fun and profit, and it looks like that mindset is paying off.)

    • I think here people are waiting for the "The circle is now complete.... once I was e-waste now I am the cleaner product." jokes.
      • Ah, yes; I think to draw the line at using cremains for making stronger concrete, tho. Then again, when I'm done with my bod and whatever use the medical folks can get from it, it might make sense for the remains to end up in a highway bridge or something - might as well get some use for the stuff rather than getting buried in the ground or sitting in an urn on some shelf. Another possibility might be as part of compost.

  • Too bad if the old PCB's don't use lead free solder. They're already covered in the copper they're trying to absorb.

    • by iksbob ( 947407 )

      Not even reading the summary, now? It says right there "the nonmetallic fraction of waste circuit boards". So were talking about a ground-up mixture of fiberglas and epoxy resin here.

  • From the article:

      Although the boards can become effective adsorbents, he says the method for making the materials may not be as energy efficient and cost effective as for other adsorbents, such as granular ferric hydroxide, because of all the processing steps needed to produce the treated powder.

    Conclusion - its dead before its even starts.

    • From the article:

      ...method for making the materials may not be as energy efficient and cost effective as for other adsorbents...

      Conclusion - its dead before its even starts.

      Right, because no one has ever figured out how to make a chemical process more energy efficient or cost effective before.

  • Ok, so now I have ground up circuit board contaminated with heavy metals.

    What can I do with this? Sell it to China for incorporation into dog food and baby formula?

  • Next thing you know the Chinese will be using petroleum products to clean up oil spills. Crazy Asians.
  • "The researchers processed the nonmetallic fraction of waste circuit boards into a powder and found that it adsorbed metals like copper, lead, and zinc"

    I'm not going to read the article (I am a slashdot user after all), but where in the world of electronic waste do you find PCBs without any metal? That would mean they don't have any traces or solder joints... unlikely to say the least.

    • by Ignacio ( 1465 )

      Either as wire-wrap perfboards, or you heat up 2-layer PCBs (to burn out the adhesive holding down the traces) and strip out the vias.

    • by erice ( 13380 )

      "The researchers processed the nonmetallic fraction of waste circuit boards into a powder and found that it adsorbed metals like copper, lead, and zinc"

      I'm not going to read the article (I am a slashdot user after all), but where in the world of electronic waste do you find PCBs without any metal? That would mean they don't have any traces or solder joints... unlikely to say the least.

      Two layer PCB's with the surface metal already stripped off. More likely left over material when odd shaped PC boards were cut from rectangular sheets.

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