Trondheim Fjord Basin GREENHOOD

Coordinating partner

NTNU (Norwegian University of Science and Technology)

location_on Location Svanem Biogass AS, Heim municipality, Trøndelag, Norway

The Trondheim Fjord Basin represents Trøndelag County, a region facing considerable nutrient surpluses due to high-intensity aquaculture and livestock production. While mineral fertilisers are still widely used for crop production, nutrient accumulation in soils and water bodies poses environmental risks, particularly eutrophication.

Challenges

The region experiences a significant phosphorus surplus, primarily driven by aquaculture and livestock sectors.

The region experiences a significant phosphorus surplus, primarily driven by aquaculture and livestock sectors. Although farmers continue using mineral fertilisers, this dual nutrient input leads to accumulation and nutrient runoff, threatening water quality in the fjord basin.
Key factors contributing to nutrient loading:
- Norway produces ~50% of the world’s Atlantic salmon; production is expected to triple or quadruple by 2050.
- Only 2–3% of fish sludge is currently collected from land-based smolt/post-smolt facilities.
- Fish sludge from open-sea aquaculture remains largely uncollected.
- Limited land availability to apply nutrient-rich digestate from biogas plants.
- Continued reliance on mineral fertilisers despite nutrient-rich waste sources.

These factors result in an imbalance in nutrient distribution and increased risk of eutrophication and greenhouse gas (GHG) emissions, including nitrous oxide.

Efforts needed to reduce nutrient loading:

Develop scalable supply chains for nutrient-rich biobased fertilisers (BBFs) derived from manure and fish waste.
Expand biogas infrastructure while ensuring digestate is further processed to reduce local nutrient pressure.
Improve fish sludge collection, including from saltwater farms.
Enhance nutrient monitoring and develop digital tools to support nutrient efficiency strategies.
Foster stakeholder engagement and adoption of novel circular approaches.

Objective

Support circular nutrient management in Trøndelag County by:

Reducing nutrient inputs to the Trondheim Fjord Basin.
Creating efficient supply chains for BBFs from livestock and aquaculture waste.
Substituting mineral fertilisers with sustainable alternatives.
Enabling nutrient redistribution to deficit regions.

Aerial view of Trondheim fjord, the beach and agricultural area Oesand, river Gaula and Gaulosen nature reserve in the summer

Solution

A comprehensive strategy will be implemented to improve nutrient management through innovative processing routes and stakeholder collaboration, including:

Production of high-quality BBFs such as struvite, granulates, and N-/K-enriched liquid fertilisers.
Thermal gasification of fish sludge to produce H₂-rich syngas and nutrient-rich ash for export.
Application testing of BBFs in agricultural settings.
Digital tools to monitor nutrient cycles and assess nutrient efficiency.
Bioenergy co-production (biogas, syngas) for integrated sustainability benefits.

These measures aim to reduce environmental impact while enhancing nutrient recycling and regional cooperation.

Technological approach

Key technological innovations

The project combines anaerobic digestion, drying, nutrient recovery, and gasification technologies to convert nutrient-rich waste into exportable BBFs.

Anaerobic digestion

Combining anaerobic digestion with technologies like struvite recovery and plasma treatment to produce bio-based fertilisers rich in phosphorus and nitrogen, while generating biogas as a renewable energy source.

Granulated fertilisers

Processing manure, fish sludge, and slaughter waste through drying technologies to create transportable, nutrient-dense granulates suitable for use or export to nutrient-deficient regions.

Advanced waste valorisation

Integrating gasification with nutrient recovery from digestate to produce hydrogen-rich syngas and concentrated nutrient ash, supporting both energy recovery and circular nutrient flows.

Field testing & digital monitoring

Testing bio-based fertilisers with farmers, including potassium-enriched variants, and deploying digital tools to monitor nutrient cycles and inform regional nutrient management strategies.

Get engage

Stakeholders, researchers, and businesses are invited to collaborate in advancing sustainable nutrient management solutions for the Trondheim Fjord Basin . Find out how you can contribute to ongoing initiatives and policy developments.

Get involved

Publication

20 March 2025

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GREENHOOD Webinar: Rebalancing nutrient flows in regional ecosystems across Europe

GREENHOOD hosted its first introductory webinar on 20 March 2025. The event was designed to showcase the comprehensive...

DOI 10.5281/zenodo.15056374

05 February 2025

25
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22
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GREENHOOD Press Release: A European Initiative to Rebalance Nutrient Flows for a Sustainable Future

Press release for the launch of the GREENHOOD project, a four-year Horizon Europe Innovation Action aimed at developing...

DOI 10.5281/zenodo.14809181

Partners

Affiliated partner

Subcontractor

The region experiences a significant phosphorus surplus, primarily driven by aquaculture and livestock sectors.

Support circular nutrient management in Trøndelag County by:

A comprehensive strategy will be implemented to improve nutrient management through innovative processing routes and stakeholder collaboration, including: