GREENER solutions for contaminated soil and water

Tauw Group participates in the EU-Horizon2020 project 'GREENER - Integrated Systems for Effective Environmental Remediation'. GREENER proposes the development of green, sustainable, efficient, and low-cost solutions for soil/sediment and water bioremediation, by integrating several remediation strategies with innovative bio-electrochemical technologies.

02 October 2020

Every year millions of tons of inorganic and organic substances from industrial, domestic, and agricultural sources enter our soils and aquatic systems, negatively affecting human health, living organisms and essential ecosystem services. Not only the number of contaminated sites worldwide but also the costs to treat or dispose contaminated soil and water have significant economic consequences.

Integration of bio-electrochemical remediation approaches

Within the EU-funded project GREENER - Integrated Systems for Environmental Effective Remediation – a consortium of 16 European and 4 Chinese partners are working together on bio-based remediation technologies for treatment of contaminated soil and water. The final aim is to develop more sustainable -GREENER- but also cost-competitive remediation approaches that substitute or minimize the use of energy-intensive and waste-generating physical-chemical technologies. The project kicked-off in March 2019 and will go on for a total of four years.

To achieve this purpose the GREENER consortium is working on the development of various soil and water bioremediation approaches that stimulate the activity of microorganisms (bacteria, archaebacteria and fungi), algae or plants to transform chemicals into non-hazardous products.

At the core of this project is the integration of bioelectrochemical systems with other bioremediation approaches into so-called hybrid remediation strategies. Bioelectrochemical systems are based on the principle that some microorganisms are electrochemically active. That is, they can exchange electrons with conductive solid materials such as electrodes; thus, promoting either oxidative or reductive reactions. This “electroactivity” enables some microorganisms to obtain energy for growth and cell maintenance very much the same way as we humans and other living beings transfer electrons from the food we consumed to oxygen. Taking advantage of these capabilities energy positive processes can be stimulated that result in microbial activity with the concomitant generation of electricity and hydrogen. 

From lab to real environmental settings

The utilization of microorganisms and plants for treatment of contaminants is historic but also eminently modern. For instance, well-established biotechnological processes such as activated sludge and anaerobic treatment systems that remain active today were developed at the beginning of the 20th century. The expansion of biogas plants in the last two decades has highlighted further the potential of microorganisms to provide an alternative renewable source of heat and power.

While processes in environmental biotechnology work according to well-established principles of microbiology and engineering, the application of these principles in real environmental settings, that is, outside of the test tube or the laboratory reactor is not straightforward. Real environments are inherently complex and heterogeneous in space and time, making the gap between the lab and the field a huge milestone.

Bioremediation was a field burgeoning with promise three decades ago, but the applications have been slow in coming. Inappropriate implementation at settings or contamination levels not amenable for biological transformation or poor site characterization -with presence of additional contaminant sources- often resulted in poor treatment performance. The lack of knowledge and acceptance by regulators has been a drawback for considering biodegradation as remedial treatment. In addition, sustainability-related parameters such as energy consumption, emissions and waste generation are often not taken into account in technical-cost assessments for treatment selection. As a result conventional approaches (e.g. excavation, pump & treat) are still the most widely adopted options.

Link-building by environmental engineer

As awareness raises for better environmental standards and waste disposal costs become more expensive, society needs to move into a more bio-based economy, further exploiting the potential of renewable energy sources, biological systems and nature-based solutions. This means also new opportunities for innovative biotechnological applications in the field of soil and water decontamination.

However, for successful implementation of bioremediation at real environmental settings it is critical to prevent mistakes from the past, appropriately guide the transition from the lab to the field and reinforce the link between scientists, regulators and stakeholders. It is equally important to inform and encourage regulators to consider alternative remedial options and provide opportunities to test new technologies.

And this is particularly the stage at which the environmental engineer comes into play. Without profound knowledge of site characteristics and contamination extent, the regulatory framework as well as the stakeholder responsibilities and needs, implementation of biological treatment is not possible. At the same time lack of technology understanding by the environmental engineer will result in missed opportunities for implementation, poor remedial design and process control or lack of solid argumentation to convince regulators of the technological benefits.  

Tauw’s role in the GREENER project

Within the GREENER project Tauw has taken over major responsibilities including:

  • Supply of site contaminated materials to partners
  • Scaling-up of biotechnologies
  • Leading pilot testing in the field for water treatment
  • Evaluate technology competitiveness and compatibility to existing treatments
  • Support in communication and dissemination activities.


In order to do this, Tauw relies on multidisciplinary expertise as well as on an international European network of Tauw offices and colleagues that is truly “alive” and is also lived within the company. During the first year of GREENER a total of 10 Tauw offices from Spain, Belgium, the Netherlands and Germany were involved in supplying site materials to our partners at universities and research centers. Without their involvement and the will of the clients and site owners to support the development of novel and more sustainable technologies, this effort would not have been possible.

Together with the GREENER partners Tauw is working during this second year of the project on the development of “Key Performance Indicators”, that is, general and technology specific metrics that allow evaluation of technology performance and progress as well as comparison to other existing treatment technologies.

In addition, Tauw is looking at the potential of various sites where testing of bioremediation approaches and bio-electrochemical systems in real settings may add an alternative or a complementary approach to ongoing remedial measures. Some of these applications include the removal of metals from groundwater by bio-precipitation, the combination of bio-electrochemical systems with plants to create a natural hydraulic gradient for groundwater containment and contaminant treatment, or the removal  of both metals and organic compounds from wastewater streams.

The focus for the last two years will be on field testing of the most promising biotechnologies. Tauw will lead the implementation of bioremediation technologies for water treatment.

Re-thinking sustainable progress

As we enter the third decade of the 21st century in the middle of a climatic and now a global pandemic crisis both related to the long-term non-sustainable exploitation of our natural resources it is time to critically re-think the way we want to shape our present and future for ourselves and the generations to come.

The participation of Tauw in R&D Programs is crucial to remain competitive and keep offering innovative, greener, and nature-based solutions to both the private and public sectors. For over 90 years the consultants and engineers of Tauw have been providing impactful and sustainable solutions by combining strong expertise with valuable partnerships. Over the years, this has resulted in many tangible and innovative solutions for soil and groundwater related challenges.

The synergistic effort of scientists, environmental engineers and authorities is essential to provide sustainable strategies and solutions for the challenges of the 21st century that receive social acceptance and contribute to a better environment.


“The GREENER project receives funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 826312”. The content of this article expresses the author's view. The EU-Commission is not responsible for any use that may be made of the information it contains.

<The Dutch version of this article is published in the magazine 'Land + Water' of september 2020>

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