Scientists at Heriot-Watt University are investigating how plant or food waste waste could be used to help microbes clean up contaminated soil.

There are over 300,000 recorded sites in the UK contaminated with pollutants like petrochemicals, with a lost economic value of over £1 billion.

Various remediation methods are available but they mostly rely on intensive treatments that require expensive onsite infrastructure, energy and resource use.

Heriot-Watt environmental microbial ecologist, Dr Tony Gutierrez, is exploring a more sustainable solution, using readily available natural resources.

With funding from the Biotechnology and Biological Sciences Research Council, he is testing a combination of 'biochar' and microbes as a soil cleaner.

Biochar is the result of putting plant or food waste under a very high heat in the absence of oxygen. It’s a charcoal-like substance that can be used to improve soil quality and yields of agricultural produce.

Dr Tony Gutierrez said: “There are indications it could be useful to help remediate soil contaminated with toxic chemicals and organic pollutants. Being highly porous, biochar could be used as a carrier of certain types of microorganisms needed to remove pollutants from contaminated soil. We’re mixing different biochars and microorganisms to find the best combination to clean up contamination.

“We’ll be trialling biochar made from agricultural waste, and we have a few microorganisms in mind that are good at degrading hydrocarbons. Soil contamination is an issue all around the world, whether from accidental spills or leaks and gradual seepage of pollutants. We’ll be using waste products and microbes to create a sustainable, inexpensive solution to a manmade problem.”