VATIS UPDATE Article

Scientists from the National University of Singapore (NUS) have re-engineered the Chromobacterium violaceum bacterium to give it the ability to create enzymes that can recycle metals such as gold, platinum and palladium from e-waste. This means barrels of poisonous chemicals such as cyanide or concentrated acids – now often used to dissolve metals in e-waste before they are recovered through electrolysis – could one day be replaced with pools of this common soil bacterium. When immersed in the bacteria, the metals are dissolved and then converted into solids without the need for electrolysis.

“This method is safer and more environmentally sustainable,” said Yew Wen Shan, at NUS. Using the example of cyanide, which is often also used in gold mines to extract the precious metal, he said that, as it is highly poisonous, extra safety infrastructure is needed to prevent its fumes from escaping the facility. It is also harder to scale up operations using such harmful chemicals as there are regulations that limit how much can be used. They can also stay effective for at least three months, compared to chemicals which lose their effectiveness after a few uses.