Phytoremediation is the use of plants to clean up contaminated soil and groundwater, isn’t it?
The plants are in fact the hosts of a “cleaning team” of bacteria. The bacteria on or inside the plants interact with the bacteria at the contaminated sites and the plants convert the pollutants into carbon dioxide (CO2) and water. If the pollution is concentrated in the groundwater deep under the surface, we plant trees such as poplars, which grow quickly and can suck up large quantities of water. In a few years, plants can clean up an entire field in an organic way.

What are the main advantages of this method?
It’s relatively cheap and the ecological footprint is very low. You only need to plant and care for the flora, which use the power of the sun to fulfil their task. Classic remediation methods consist of digging off a layer of soil or pumping out the groundwater, after which the soil or water is purified at specialised centres. This way of working requires a lot of energy and transport activity, resulting in a big impact on the environment.

Why is it not the standard technique yet?
First of all, you cannot always apply this green method; it’s impossible if buildings are in the way for example. We also need to keep refining the technique, but the main reason is that the enterprises of the sector are not acquainted enough with phytoremediation. Fortunately, the situation is changing. Since we started this research in the middle of the 1990s, we have opened many eyes here and abroad.

You’re now providing expertise for a demonstration project by consultancy firm Arcadis
The goal of Arcadis and the Flemish waste management agency OVAM, which is partly financing this project, is to raise awareness of this natural method among actors in the land remediation sector. The Arcadis project is taking place at Genk, where our team is also involved in cleaning up a site of car manufacturer Ford. We are also collaborating with partners from 10 countries in the European project Greenland.

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