Mexican researchers have developed a peanut shell-based biofilter capable of removing industrial solvents and other pollutants from the air.
Relying on bacteria that naturally inhabit the insides of peanut shells, the innovative filter resembles a conventional kitchen extractor. However, it does not only separate and store toxic pollutants; it degrades them into carbon dioxide and water, which are used by the bacteria to grow.
"The peanut shell is special for these applications because it is naturally hollow and has an area of contact with air, which favours the development of microorganisms," said Raul Pineda Olmedo, a biotechnology expert at the National University of Mexico who led the team behind the invention.
The prototype has been designed to clean air contamination in factories handling inks and solvents. Yet the researchers believe it could find many other applications. For example, it could be used in cars to clean incoming air by not only filtering dust, but degrading harmful pollutants to harmless substances.
Two types of microorganisms – Fusarium and Brevibacterium – are responsible for the air-cleaning properties of the peanut filter. To make the technology efficient, the filter requires a 28-day period for the microorganisms to multiply sufficiently to be able to handle the task.
Peanut shells are a plentiful and cheap material in Mexico for which there is presently little use.
The researchers are currently looking for partners to help them commercialise the technology and develop further applications.