NuReDrain: the end of the beginning

06 July 2023 - Published by Charlotte Boeckaert
After six interesting years, NuReDrain has ended. The consortium can only be grateful for this exciting project that presented itself as an extremely fruitful quest with great partners and an unique collaboration. But the end of the project does not mean the end of the research and development of filter systems for nutrient removal. On the contrary!


Discover here how the results and insights of the project will be further capitalized in future activities of the partners:


University of Copenhagen
“The University of Copenhagen will continue its effort on filter solutions in the coming years.
Firstly, we will be working with filters to capture phosphorus which is released when lowland soils are rewetted. Rewetting and hence the reconstruction of wet meadow soils may be an efficient way to reduce greenhouse gas emissions as drained meadow soils emit large quantities of CO2.
However, when meadow soils are rewetted, phosphorus bound to iron oxides may be released. Meadow soil filters can be used to retain the phosphorus released. A special challenge is to cope with the high concentrations of dissolved organic matter in the leaching water.
Secondly, we will continue our work with the development of engineered iron-oxide rich porous filter materials for phosphorus retention with particular focus on recyling, reuse and prevention of clogging.”

Ghent University and Inagro
“Inagro and Ghent University have decided to continue their collaboration. They will test the two dig-in filters at the Staden field site and one upscaled filter at INAGRO for an additional drainage season. They aim to assess the long-term performance of the dig-in filters and to resolve the recurring clogging problem associated with the open pond water for upscaled P filters.”

University of Rostock (UROS)
“During the NuReDrain project, UROS constructed eco-hydrological catchment models for different purposes. We used these models to evaluate the potential of constructed wetlands to reduce nitrate pollution in agricultural catchments. In the future, we will use these models for further scenario analyses. In this context, we will integrate the cost-evaluation tool that has been developed in NuReDrain 2.0. Some years ago, we built a woodchip filter near the city of Rostock. We will use the NuReDrain results to further optimize the filter configuration in order to increase the performance of this denitrifying bioreactor.”

PCS Ornamental Research
During NuReDrain, different N- and P-filters were tested at the Ornamental Research Centre in Destelbergen. A do-it-yourself filter with first a P-filter (filled with iron coated sand (ICS)) and secondly a MBBR (Moving Bed BioReactor)-filter to remove nitrogen is paired. This system is easy to construct and a manual to build a MBBR is available on the Nuredrain website .
We will further disseminate the results we obtained with these filters since we were able to remove up to 90% of the P and up to 60-70% of the N from the influent. We will also support Flemish growers to obtain funding for the installation of these filter systems.

KU Leuven
The NuReDrain project demonstrated that Moving Bed Biofilm Reactors (MBBR) offer a compact alternative to reduce nitrate concentrations in drainage water and effluent from greenhouses. With the gained knowledge, KUL can provide customized advice to companies and set up experimental research to support implementation in the field. As a research group, we would like to become a "center of excellence" for the research on MBBR technology and to develop further cooperation with technology suppliers. We see innovations concerning water reuse or nutrient recovery as challenges for the future. In particular, we are considering further research into the applicability of the zero-valent iron (ZVI) filtration technology in combination with ion exchange as an effluent polishing technique.

As a research organisation in the area of cleantech and sustainable development, VITO aims to further develop the large-scale production of iron-based filter materials from sludge materials. This large-scale production should allow for the production of iron-based filter materials without requiring an energy-intensive thermal treatment. Furthermore, we would like to demonstrate a fully automated filter material regeneration (desorption) set-up at filter systems in the field.

In follow up of the NuReDrain project, Vlakwa wants to support the actual implementation of filter systems in the field. Therefore, a close collaboration with the agricultural research centers will be set up to guide farmers to the correct solution. Furthermore, P valorisation remains important for the success of the filters. Vlakwa will further stimulate research on this topic.