Taking the high (tech) road
E-waste like computers and TVs isn't cheap or easy to recycle, but environmental scientists are fine-tuning a solution that could revolutionize the industry. They can actually turn your old computers into roads. Seriously.
Fri, May 22, 2009 at 05:21 AM
Researchers in China could be paving the way for something productive to come from mountains of electronic waste across the globe.
Of the 2.2 million tons of TVs, cell phones and computer products discarded in 2007, just 18 percent was recycled, according to the EPA; 82 percent, or 1.8 million tons, are choking landfills — and that's just in the United States.
Glass and paper, the low-hanging fruit of the recycling world, are relatively easy to separate and turn into "new" products. E-waste, on the other hand, is usually a complex mesh of plastic and metal that's difficult and so far expensive to "undo." Since the Information Age commandeered most of our lives, electronic waste has either been dumped into landfills or poisoned children who scavenge through it in developing countries.
Zhenming Xu and colleagues at China's Shanghai Jiao Tong University are working on new ways to remove the toxic metals from the glass and plastic in the printed circuit boards found in many of our electronic throwaways. After they're separated, the glass fibers and plastic resins are turned into a fine, metal-free powder. That powder is being tested as an additive for asphalt, to make roads longer-lasting.
Voila: From the remnants of the information superhighway to a freeway improvement project.
Jiuyong Guo says that, so far, the testing looks both safe and promising. "The new recycling process that separates the heavy metals from the other components is called 'corona electrostatic separation,' which has proved to be highly efficient, economical, and environmentally friendly," says Guo, one of the authors of the research in the American Chemical Society's journal, Environmental Science and Technology.
For decades, road construction has provided an environmentally sound answer to another nasty product: old tires. Ground-up rubber tires have served well as an asphalt additive. (Anyone who has come within a couple of miles of the raging smoke and stench of a "tire graveyard" fire knows what a scientific breakthrough that discovery provided.)
Extensive field studies will be needed, however, to determine if the Shanghai laboratory findings can translate to the real world.
"It is a good idea but it needs more work," says chemist Neal Langerman of Advanced Chemical Safety Inc.
Langerman is not involved in this Chinese study, but is an expert on a wide range of industry standards, safety and environmental contamination issues.
He says it's critical to make sure the heavy metals (arsenic, chromium, cadmium, lead) have been completely removed from the concoction that will go onto the roads.
"Researchers need to go out and lay 10-kilometer (6.2-mile) test tracks in 15 different locations or so, and monitor them," Langerman says.
There could be some differences in how the material reacts in hot and cold climates. The lab results show the powder creates a stronger paving material less likely to soften at high temperatures.
The obvious answer to electronic waste is to create less of it. But with hundreds of millions of people discarding their gadgets as soon as some sexy new incarnation of a phone or laptop hits the market, that's not likely.
The EPA reports some progress in lightening the world's load of all this electronic detritus. Both U.S. and European Union mandates are reducing the amount of lead and flame retardants in electronics. And manufacturers are increasingly identifying where the toxic components are located inside products so they're safer to handle during recycling. Recycling the old products is still prohibitively labor-intensive.
While there's no national mandatory electronics recycling program, 18 states and New York City have laws mandating "take back" and recycling of some used electronics.
The Chinese research team is optimistic that their research could help deal with a pollution problem that's both economically and politically damaging to China.
"Private companies and governments are being persuaded to get ready to start investing in the solution, but it will take some time," Guo says.
(MNN homepage photo: BenGoode/IstockPhoto)
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