1. Innovation Sludge from RAS Keep it simple
Martin Vestergaard, Production Manager
NCE Aquaculture og Skrettings Settefiskforum
Bodø 2016, August

2. Agenda Aquapri and Pike perch farm Sludge from RAS
Concentration methods
Disposal
Sludge – ressource or problem
Circular economi

3. AquaPri Main production Rainbow trout (6000 t), Trout roe
Danish family owned company that has been
in the seafood industry for over 100 years.
Main production
Rainbow trout (6000 t),
Trout roe
Pikeperch (600t).
Facilities
17 land based farms
6 sea cage sites
Slaughter house
Transport facilities for live fish.
Employees
70 people full time
70-80 seasonal workers

4. What is a Pike perch? Gjørs
A freshwater, carnivorous fish found in lakes and river systems of europe, north Africa and west Asia as well as the Caspian Sea and Baltic Sea (brackish water).
Perceived as one of Europe’s most valuable food fishes.
Pikeperch has a white flesh which is described as having a delicate taste and juicy consistency, as well as being relatively boneless compared to other freshwater white fleshed fish species.

5. Pike perch farm Phase 1: 600 tons production pr year of
1 kg pike perch for consume
Phase 2:
Utilize 1. floor for integrated Broodstock and
Fingerling production

6. Pike perch farm Groundwater 50-150 l/kg feed 150 M3/day Temp. 21-23 C
Ground area M2
1. Floor M2

7. Pike perch farm

8. Pike perch farm

9. Pike perch farm

10. Pike perch farm– water treatment

11. Drumfilters and hydrolyse tank
From hydrolysetank, water goes to Denitrification filter

12. A question of final disposal…......
How much thickening of the sludge?
A question of final disposal…......
Discharge to nearby sea, river etc
Stored at a landfill
Used for biogas (min. 12% DM)
Used as a fertilizer
Etc.

13. Regulations and cost Cost for disposal
Regulations for sludge and rejectwater restrict possibilities –
The rest is economics and technology
Cost for disposal
Preparation (concentration)
Investment
Running cost and maintance
Transport
Compensation end user

14. Sludge thickening 1-2% DM
A simple way:
Sludge tank and lagune
Pure sedimentation
No flocculants
Sludge tank M3
Wastewater reservoir M3

15. Irrigation and sludge Sludge used as fertilizer on agriculture land.
20-25 ha is needed for 600 tons pike perch production
Own land is to prefer 

16. Sludge analyse, example
Kvælstofnorm, N
100
kg/ha/år
Phosphornorm, P 30
Årlig gyllemængde, Total volumen
3000
M3 gylle
Prøveresultater fra d.
max værdier
kg/M3 gylle
Kg i alt
Nødv. Ha
Tørstof
0,74 %
7,400
22.200
Kvælstof, total
470
mg/kg
0,470
1.410
14,10
63000
mg/kg ts
0,466
1.399
Phosphor, total
9400
0,070
209
6,96 70
210
Bly 3
120
0,000
0,07
Bly pr. phosphorenhed
160
mg/kg TP
10000
Cadmium
0,41
0,8
0,01
Cadmium pr. phosphorenhed 44
Chrom
2,2
0,05
Kobber 20
1000
0,44
Kviksølv
0,04
0,00
Kviksølv pr. phosphorenhed
4,2
200
Nikkel
2,6
0,06
Nikkel pr phosphorenhed
270
2500
Zink
4000
0,002 5

17. If increased concentration is needed….
No landspace available nearby
Different methods for thickening

18. Sludge thickening 5% DM Coagulant pH-regulation Polymer Belt-filter
Mixer tank
Coagulant
pH-regulation
Polymer
Belt-filter
Chamber 1: High turbulence  Coagulation phase
Chamber 2: Flocculation phase, small particles  bigger particles
Chamber 3: Particles ready to sediment – mixing high enough to avoid that sedimentation

19. Sludge thickening 15% DM
Coagulant
pH-regulation
Polymer
Geotube

20. Sludge thickening 25% DM Coagulant pH-regulation Polymer
Chamber filter press

21. Sludge thickening 30% DM Coagulant pH-regulation Polymer Belt-filter
Centrifuge or screw …

22. Sludge thickening +90% DM
Coagulant
pH-regulation
Polymer
Belt-filter
Composting

23. Sludge thickening – Alternative
Sludge mixed with woodchips and composting by use of worms

24. A resource or a problem? So far more a cost than a ressource
Nutrients (Mainly N and P)
Much cheaper and easier to use artificial fertilizer
Energi (Organic carbon boundings)
Energi source for microbiology in soil
Sustainability and long perspective

25. Circular economi
Integrated multi-trophic aquaculture (IMTA)

26. Using a mass balance approach:
The production of 1 tonne (t) of salmon releases app. 50 kg of nitrogen into the environment which could support the growth of 10 t of seaweed or 5 t of mussels over the course of the production cycle of the salmon.
From the 10 t (w/w) of seaweed produced for every tonne of fish, it would be possible to produce 164 kg of protein and 9 kg of marine lipids.
Need for area:
cage culture of fish produces between 1125 to 1750 T/ha,
mussels 76 T/ha
and for aquatic plants 1 T/ha
1 ha of salmonproduction would require between 17 and 23 ha of seaweed to sequester 10% of the nitrogen output.

27. IMTA
To make this meaningful to the farmer, there needs to be a proven case that these products can be sold at above their production costs plus an acceptable margin.

28. Nitrify / Fertilize some wood land area?

29. Thank you for your attention