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Catalan Researchers Use Bacteria to Recover Smartphone Metals

The proliferation of smartphones and the speed at which they are being discarded is creating a huge environmental problem. The rate of replacing a smartphone is estimated at one and a half years in the U.S. and Europe, with higher-end models being replaced every four years. Cheaper units get discarded earlier because they can’t support the latest applications.

Most manufacturers are also adding to the problem by building obsolescence into the design. They limit access to new applications and versions of the operating systems, as well as prevent repairs by making the phones serviceable only by their own technicians and making the components difficult or impossible to replace.

Electronic scrap accounts for 70% of the overall toxic waste currently found in the world’s landfills. “For every million cell phones we recycle, 35 thousand pounds of copper, 772 pounds of silver, 75 pounds of gold and 33 pounds of palladium can be recovered,” according to the U.S. Environmental Protection Agency (EPA).

The energy costs and the environmental impact associated with current recycling methods make the bacteria option a very interesting proposition for the industry.

The bacteria solution

This idea entails using the metabolic activity of certain microorganisms (essentially bacteria) to regenerate the agents that are holding the metals in place and thereby unlocking them.

Compared to traditional methods, the energy requirements are minimum, since the bacteria works at room temperature, instead of the 1200-1500º C needed for melting the components. Toxic waste is also reduced by avoiding aggressive chemicals such as sulfuric or cyanuric acids currently used in hydrometallurgical procedures.

The research team, led by professor Antonio David Dorado, of the mining engineering department of the UPC, has been successful recovering most of the copper and other metals, such as gold, silver, aluminum, and platinum.

Spain is already a European leader in mobile phone recycling, with an 80% recovery rate, higher than the UK (75%), Germany and France (67%), and Italy (69%).

A serious pollution problem

As far back as ten years ago, Greenpeace slammed Apple for toxic components found in the original iPhone. Greenpeace showed tests demonstrating that the iPhone contained a number phthalates and chemicals that were reproductive toxins or carcinogens, and already banned by California law, or required a warning label.

After the European RohS 1 directive took effect in July 2006, and the subsequent RohS 2 version in 2015, the use of 10 different pollutants has been banned for all products manufactured or imported into the European Union. Those products are Lead (Pb), Mercury (Hg), Cadmium (Cd), Hexavalent chromium (Cr6+), Polybrominated biphenyls (PBB), Polybrominated diphenyl ether (PBDE), Bis(2-ethylhexyl) phthalate (DEHP), Butyl benzyl phthalate (BBP), Dibutyl phthalate (DBP), Diisobutyl phthalate (DIBP). DEHP, BBP, DBP and DIBP were added as part of DIRECTIVE (EU) 2015/863, which came into effect on 31 March, 2015.

Fortunately for factory workers and consumers worldwide, most manufacturers design their mobile devices and other electronic products to comply with EU directives irrespective of where they are sold, because otherwise it would overly complicate the supply chain.

At the same time, there are billions of mobile phones and other portable devices manufactured before the directives took effect. That means that recycling them still poses a serious environmental hazard.

Even without those polluting substances present, recycling smartphones and recovering their useful metals poses a big challenge. Current methods are based on separating the components by brute force and then melting them at high temperature — a system that is energy intensive and water intensive and releases toxic fumes into the environment.

UPC researchers, encouraged by the success rate in recovering metals and the environmental benefits of this bacteria technology, plan to open a pilot factory for smartphone recycling in Manresa outside Barcelona this year, which will be operated by UPC together with a leader in the recycling industry. 

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