Using bacteria to recycle precious metals from e-waste
E-waste and EV batteries are currently recycled through processes called pyrometallurgy and hydrometallurgy. However, they involve searing temperatures with a high energy demand and deep carbon footprint, and toxic chemicals, harmful to the environment. Alternatives are therefore being sought.
A team of scientists from the University of Coventry are scaling up one such alternative. They have been using non-toxic bacteria to oxidise and recover the precious metals – a process known as ‘bioleaching’. They’ve shown that copper is widely recoverable from discarded e-waste, and that all metals present in EV batteries can be recovered using microbes. ‘Most of the time we are using very common bacteria that have evolved to oxidise metals as part of their natural metabolism; rarer bacteria that oxidise things like silver, gold and platinum can be readily cultivated,’ says leader of the ‘Bioleaching Research Group’, Sebastien Farnaud. ‘We’re working with methods that have been on Earth for billions of years and mimicking them to solve a modern issue: that’s essentially what all biotech does.’ Read more in Geographical.
Recycling symbol can’t appear on non-recyclable items
California: “The recycling symbol—those three arrows stamped on myriad plastic items—doesn’t mean what most people think it does, and a California bill wants to change that.
The California Legislature passed a bill yesterday that would ban companies from putting the recycling symbol on items that aren’t regularly recycled throughout the state. The bill is now awaiting Gov. Gavin Newsom’s signature, and if signed into law, it would end a labelling practice that has confused consumers for decades and created major headaches for the solid-waste industry.
The ubiquitous “chasing arrows” symbol wasn’t originally meant to appear on all plastics. Rather, it was designed by a college student for a contest in the early 1970s to symbolize paper recycling. The company that sponsored the contest released the symbol to the public domain. Confusion over the chasing arrows began in the late ’80s and early ’90s, when oil and plastic companies lobbied states to make resin identification codes—which included the arrows—mandatory on all plastic, even if it couldn’t be recycled easily.
While all plastics can technically be recycled, only a small percentage actually are. Only about 9% of all plastics are recycled in the US annually, and around 9% of all plastics ever produced have been recycled. The rest are incinerated or, more likely, landfilled or scattered as litter.” Read more here.