Researchers in Hong Kong have discovered that ground-up circuit boards can be used to absorb toxic heavy metals found in water, Chemical & Engineering News reports.
Scientist Gordon McKay and his colleagues at the Hong Kong University of Science & Technology began looking into the potential of e-waste's non-metallic components, primarily plastic and aluminosilicate.
They had previously developed adsorbents, capable of mopping up heavy metal toxins, from wastewater effluents generated by the microelectronics industry. In the latest research, the scientists discovered that aluminosilicate e-waste from circuit boards could also absorb heavy metals, if it was powdered and treated with potassium hydride, then added to solutions of copper, lead and zinc.
They also found that this treated material was more effective than three commonly used industrial adsorbents. McKay's team is speaking with a Hong Kong recycler about expanding the pilot project up to industrial scale. If the e-waste is used to treat the waste water effluents generated by electronics production, McKay believes that would be tantamount to completing the circle.
About 20 million to 50 million tons of electronic waste is generated each year and the bulk of this finds its way to landfills. E-waste generated from cell phones, computers and other devices is an environmental hazard, since burning it produces toxic compounds and sending it to landfills risks the contamination of ground water from metal components. E-waste also represents an ecological and health hazard in developing countries that end up processing most of it.
In June, Frost & Sullivan said that rapid industrialization and advancements in technology have led governments in Asia-Pacific to pass regulations mandating e-waste recycling, as electrical and electronic waste accumulates. Apart from government impetus, the e-waste recycling market has also gotten a boost from the increasing awareness of the potential value of resources within e-waste.
