Typical of industrial construction, precious metals such as gold, platinum and palladium are sometimes lost given the difficulties of effectively extracting them. However, researchers from the School of Biosciences at the University of Birmingham have found a way to use microbes, similar to the common soil bacterium Desulfovibrio desulfuricans, to recover palladium from useless industrial waste. Researchers hope that by using such forms of bacteria, high quantities of precious metals can be recaptured and recycled for use in industries. While the whole process to reclaim this little bit of metal seems overly tedious, the end result holds considerable value. Palladium itself is one of the most precious resource metals on Earth, boasting unique chemical properties. This metal can in fact be used as an active element in autocatalytic converters able to reduce greenhouse gas emissions.
Photo credit © Flickr Nickster 2000
According to Dr Kevin Deplanche, who is leading the research team, “These metals are a finite resource and this is reflected in their high market value. Over the last 10 years, demand has consistently outstripped supply and so research into alternative ways of recovering palladium from secondary sources is paramount to ensuring future availability of this resource.” In turn, by getting microbes to harvest particles of metal, they could be doing their part to save the environment.
During their research, the science team discovered that Desulfovibrio desulfuricans was able to reduce palladium in industrial wastes into metallic nanoparticles with biocatalytic activity. Now that the team have discovered the molecules involved in this process, they believe that Hydrogenase enzymes located on the surface membrane of the bacterium would be able to carry out the reduction of palladium, which would in turn result in the accumulation of catalytic nanoparticles. The bacterial cells coated with palladium nanoparticles are known as ‘BioPd” and are believed to be the microbes with the greatest potential for generating clean energy.
“Research in our group has shown that BioPd is an excellent catalyst for the treatment of persistent pollutants, such as chromium, that is used in the paint industry. BioPd could even be used in a proton exchange fuel cell to make clean electricity from hydrogen,” said Dr. Deplanche. “Our ultimate aim is to develop a one-step technology that allows for the conversion of metallic wastes into high value catalysts for green chemistry and clean energy generation.”
Lead photo credit: Kevin Deplanche