First Danish delivery of recycled nitrogen fertiliser

Denmark has now also received its first delivery of nitrogen fertiliser produced by side streams from water treatment.

Denmark has now also received its first delivery of nitrogen fertiliser produced by side streams from water treatment. The fertiliser is produced within the LIFE RE-Fertilize project, a collaboration between EasyMining, owning the process, Ragn-Sells, BIOFOS and Lantmännen. 

In March 2022, the first Swedish delivery took place at a farm just outside Uppsala in Sweden, before moving the pilot plant to Lynetten in Copenhagen, Denmarks biggest wastewater treatment plant. This time, about 17 m3 liquid ammonium sulphate produced by the nitrogen captured in the reject water from the wastewater treatment plant, got delivered to Eriksholms Gods, an hour from Copenhagen, Denmark’s capital.

Therese Åström, plant nutrition specialist at EasyMining, points out that the fertiliser produced at BIOFOS wastewater treatment plant in Lynetten have very low levels of heavy metals, showing great results from the recovery process.

– In particular, it was important that it appeared to be free of important impurities, says Thomas Lundgren, CEO at Lantmännen Agro A/S.

Ole Hou, manager at Eriksholms Gods, is planning to use the ammonium sulphate mixed with N32, a conventional nitrogen fertiliser, spreading it in liquid form. But for future deliveries he thinks it is possible to mix it with plant protection products for fungal control in the field.

– The intention is to use it as foliar fertiliser in the spring since it will have best effect at that time. This delivery was fine and without impurities, which is important for the smaller nozzles used for spraying it on the leaves since the product must flow without particles, says Ole Hou.

All three agree that the ammonium sulphate coming out of the process today with just 11% concentration, would increase in value and application possibilities as a more concentrated product.

– We are during the fall trying out different ways for the product, both as a more concentrated liquid and crystallised, and a greenhouse pot trial performed together with Lantmännen, will evaluate the fertilisers efficiency compared to other ammonium sulphates, says Therese Åström.