Cleaning up fuel spills with bacteria

Published: 18 October 2018

The growing world population demands more and more industry and agriculture. In turn, they result in more soil and groundwater pollution. Incidental leak near storage tanks or during waste disposal allow pollutants containing non-organic or organic compounds to enter the soil.

Organic pollution sounds natural, but it isn’t

The term ‘organic pollution’ sounds natural but it really does mean aromatic and aliphatic hydrocarbons such as benzene and pyrene. Both are proven carcinogens for humans and animals. It is important to investigate how we can clean up these contaminated water and soil systems, preferably without adding other substances. This approach to cleaning using natural methods is known as ‘bioremediation’.

Also effective with fuels like petrol

Bioremediation is seen as a cost-effective and sustainable solution to accelerate natural degradation. It is already being used and studied in a few locations (Grift Park in Utrecht, for example). In her thesis, Marcelle van der Waals (Deltares, Wageningen University & Research) looked at how substances from fuels such as petrol degrade (substances like methyl tert-butyl ether (MtBE), ethyl tert-butyl ether (EtBE), tert-butyl alcohol (TBA) and benzene). She identifies the relevant micro-organisms, describes where they are located exactly and how they absorb the substances and break them down. A better understanding of this area allows us to determine whether, and how, we can work with the micro-organisms to get our soil clean again.

Marcelle van der Waals found out that we can, for example, actually teach bacteria in the laboratory to eat more and more. In the case of MtBE, that was actually remarkably successful. Marcelle: ‘It took time – we have been working on this for about three years – but of course it is encouraging that the bacteria are doing what we want now. The more contaminants you can get them to eat, the more interesting things actually become’.


From the laboratory to the field

The results are so encouraging that Marcelle’s colleagues from Deltares are now at work in the field in Amersfoort, and actually using these omnivorous bacteria on polluted soil. The aim is to find out whether the bacteria will indeed eat up contaminants outside the laboratory. Marcelle: ‘Obviously, as a researcher, you want to take the next step and put your research into practice.’

Marcelle obtained her doctorate at Wageningen University & Research on 18 October.