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 (Environ. Sci. Technol. 2013, DOI: 10.1021/es4001664).
About 20 to 50 million tons of electronic waste is produced worldwide each year, and most of it is incinerated or dumped into landfills. Environmental scientists worry about the ecological and human health hazards caused by this e-waste, especially in developing countries that receive the bulk of the waste. Burning the plastic-metal mix in printed circuit boards releases toxic compounds such as dioxins and furans. In landfills, the metals on the boards can eventually contaminate groundwater.
But recycling circuit boards is expensive. Only the metal parts of the boards have reuse value, so the nonmetallic parts must be separated out from the e-waste, which is a costly process.