Are willow trees into Heavy Metal?

A fresh perspective on risk management

The province of Groningen has started a project in Appingedam where risk management of contaminated locations is viewed in a new way. Research is conducted to check if the area, which is polluted with heavy metals, can be managed in a sustainable manner by cultivating willow trees and processing the obtained wood to a sustainable product.

The contaminated location is an old part of a business area of the former strawboard factory ‘De Eendracht’. The intention is to transform this former industrial site into an attractive area for recreational activities, like hiking and cycling. However, a part of the site (about 3 hectares) is contaminated with heavy metals and is not open to the public. To achieve this willow trees have been planted. The dense cultivation of the trees ensures that people can’t access the area, which prevents direct contact with the contamination.

The beauty of willow trees is that they are capable of accumulating or binding the heavy metals, thereby decreasing the risks and cleaning the soil in a natural way.

Do risk management and the creation of a sustainable product go hand in hand?

The province of Groningen desires the answers to several questions during this project.

Is it possible to create sustainable added value with willow trees, which are planted on contaminated soil and does the quality of the soil improve? To obtain the answers the province of Groningen has asked Bioclear earth to monitor the site of ‘De Eendracht’ located in Appingedam for a period of six years.

We will determine if the health and quality of the soil is actually improving. To this end innovative soil screenings are applied like the iSQ test. This test, developed by Bioclear earth and the Vrije Universiteit Amsterdam, determines the toxicity of the soil in a very effective manner.

Bioclear earth also investigates how the produced willow wood can be processed in a sustainable way. Options one can think of are the use of wood for heat supply of the building on the premise. Another option is to use the willow wood as feedstock in the form of fibres.  

Research is conducted to see if the trees absorb the metal or if the trees bind the metals in complex forms in the soil and how this affects the soil’s health. In short, do the ecological risks decrease? If the results are positive this concept could be attractive for other locations as well, to effectively manage risks and create sustainable products at the same time.

Now let’s hope willow trees are big fans of “Heavy Metal”. 

Do you want to know more about this project, please contact Freek van den Heuvel.

Freek van den Heuvel
Consultant water quality and phytoremediation