Nuredrain 2.0 started

24 January 2022 - Published by Charlotte Boeckaert
Last summer, the Interreg secretariat for the North Sea Region approved our proposal for the extension of NuReDrain until June 2023! With NuReDrain 2.0, we continue our research into the development of filters and filter materials for phosphorus and / or nitrogen removal in drainage water and effluent from greenhouses and their usability in practice.


In the past years, different nutrient removal filter systems have been developed and tested in Belgium, Denmark and Germany. The nitrogen (N) and phosphorous (P) removal efficiency varies between 60 and 95%, depending on the flow and nutrient concentration in the water. Filter systems can be used for tile-drain water and effluent from greenhouses. Moreover, investment and operational costs have been determined confirming that the filter systems are cost efficient and valid mitigation measures.

In NuReDrain 2.0 following activities will be set up:

  • Ghent University will upscale its prototype filterbox for P removal. It will be investigated whether a mean 80% P removal can also be attained when the filterbox is enlarged treating water from a collector tile-drain rather than an individual tile-drain. The system will no longer be put in the ditch but at the edge of the field. Inagro will continue monitoring 5 filterboxes in the field. By doing so, the P removal efficiency can be mapped throughout consecutive years.
  • Inagro will continue its work at the Godelieve test site. This site entails 3 different N removal systems being a constructed wetland, a moving bed bioreactor (MBBR) and a wood chips basin. Long term monitoring will elucidate removal efficiencies, required maintenance works and costs of the 3 systems.
  • KU Leuven and Copenhagen University will join hands by combining their proper systems: the MBBR and Zero Valent Iron (ZVI) filter will be combined to remove high and low nitrogen concentrations and to valorize nitrogen to an ammonium fertilizer. The combined filter system will be tested at a greenhouse in Belgium.
  • PCS Ornamental Plant Research will further test its do-it-yourself filter systems in which a MBBR is combined with a P filter to simultaneously remove N and P from greenhouse effluent. The 2-in-1 filter system will be installed and monitored at 5 different horticultural growers.
  • VITO will focus on the regeneration of P saturated filter material as P is removed from the water by binding P to iron oxide granules. VITO has a pilot enabling the regeneration of material in the order of kilograms.
  • Rostock University will draft a step-by-step manual to be used as a blueprint for the identification of appropriate places for N or P removal technologies in other catchments in the North Sea Region. This manual offers an important starting point for the implementation of filter technologies.
  • Finally, Vlakwa will elaborate viable financial models for the practical implementation of the filter systems. Stakeholders involved will be among others farmers’ organizations, agrifood processing companies, drinking water production companies, the Flanders Environment Agency and the Flanders Land Agency. This activity will foster the acknowledgement of the filter systems and will hopefully result in acceptance and uptake of the filter systems. By doing so, we hope to realize a boost in the number of organizations that will adopt our solutions by the project end in June 2023.