June 1, 2009

1 min read

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Old Circuit Boards Hit the Road

By Mark Fischetti

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Millions of printed circuit boards from discarded electronics are tossed into landfills every year. In addition to the volume of waste, the material can leech chemicals into the soil. As an alternative, researchers at Shanghai Jiao Tong University in China are finding various ways to reuse the panels, including as an additive in asphalt.

Xu Zhenming and his colleagues stripped the boards of all components, pulverized the remains into a powder and used an electrostatic separator to remove fine bits of any remaining metals, leaving a pulp of glass fibers and resin. They then added those remnants to warmed asphalt, to see if the pulp would act as a binder. Binders such as ground tire rubber and charcoal are typically added to improve asphalt’s stiffness at high temperatures (to reduce rutting) and its pliability at low temperatures (to prevent cracking). The pulp improved both properties, especially when the powder grains were made as small as possible. Zhenming’s team is testing the modified asphalt to check how it holds up to outdoor conditions over time. It is also experimenting with forming the pulp into sheets that could be made into structures such as park benches and fences.

Rights & Permissions

Mark Fischetti was a senior editor at Scientific American for nearly 20 years and covered sustainability issues, including climate, environment, energy, and more. He assigned and edited feature articles and news by journalists and scientists and also wrote in those formats. He was founding managing editor of two spin-off magazines: Scientific American Mind and Scientific American Earth 3.0. His 2001 article “Drowning New Orleans” predicted the widespread disaster that a storm like Hurricane Katrina would impose on the city. Fischetti has written as a freelancer for the New York Times, Sports Illustrated, Smithsonian and many other outlets. He co-authored the book Weaving the Web with Tim Berners-Lee, inventor of the World Wide Web, which tells the real story of how the Web was created. He also co-authored The New Killer Diseases with microbiologist Elinor Levy. Fischetti has a physics degree and has twice served as Attaway Fellow in Civic Culture at Centenary College of Louisiana, which awarded him an honorary doctorate. In 2021 he received the American Geophysical Union’s Robert C. Cowen Award for Sustained Achievement in Science Journalism. He has appeared on NBC’s Meet the Press, CNN, the History Channel, NPR News and many radio stations.

More by Mark Fischetti
SA Special Editions Vol 19 Issue 2sThis article was published with the title “Old Circuit Boards Hit the Road” in SA Special Editions Vol. 19 No. 2s (), p. 10
doi:10.1038/scientificamericanearth0609-10a
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