1. Sustainabel use of Baltic Sea natural resources based on ecological engineering and biogas production - a good exampel on land and water management Fredrik Grndahl, Industrial Ecology, KTH SE-100 44 Stockholm, Sweden Fredrik Grndahl (fgro@kth.se) Industrial Ecology KTH, Stockholm, Sweden Fredrik Grndahl, Industrial Ecology, KTH

2. Fredrik Grndahl, Industrial Ecology, KTH

3. Eutrophication the most serious environmental problem of the Baltic Sea Action plan by the Helsinki Comission (HELCOM) 21 000 tonnes N, 290 tonnes P Good ecological status 2021 Fredrik Grndahl, Industrial Ecology, KTH

4. Sustainable use of Baltic sea biomass resources based on ecological retrieval of biomass (reed and algae) for production of energy and new innovative products (including fertilizers) with an associated waste stream. Blue squares indicate technology dependent processes and the yellow clouds shows the sustainability and feasibility aspects. Grndahl et. al. 2008 Fredrik Grndahl, Industrial Ecology, KTH

5. Objectives of the study Compare the efficiency of reed and macro algae harvesting and mussel farming with respect to nutrient removal from the Baltic Sea. Provide and compare energy budgets for the full process chain from harvesting of biomass to biogas production for reed, macro algae and mussels. Fredrik Grndahl, Industrial Ecology, KTH

6. Rivers 706 000 tons/y Agriculture Traffic Atmospheric N-Fixation by deposit Cyanobacteria 264 000 tons/y 400 000 tons/y Baltic Sea Traffic 909 000 tons/y Sediments and Biomass Point Sources Loss 39 000 tons/y Denitriphication Waste water 500 000 tons/y treatment

7. Fredrik Grndahl, Industrial Ecology, KTH

8. Figure 1: Nodularia spumigena (Helcom, 2004) dw 16 - OP dw 16 - N dw 22 - GPT dw 19 - N dw 20 - OPB Figure 11: The forming fabrics after being pulled through algal rich water

9. Forming fabric Figure 7: Forming fabric is Figure 6: Outline of an oil boom with attached to the oil boom skirt forming fabric attached

10. Fredrik Grndahl, Industrial Ecology, KTH

11. Reed Grows as large monospecific stands along the Baltic coast of Sweden Swedish total reed area: 100 000 ha Biomass above ground in the middle, and south of Sweden in august: 1 kg dw/m2 Fredrik Grndahl, Industrial Ecology, KTH

12. Aquatic Plant Harvester RS 2000 Floating device with front conveyors Makes harvest of water plants possible (i.e. both algae and reed) Fredrik Grndahl, Industrial Ecology, KTH

13. Algae Heavy algal blooms and growth due to surplus of nutrients, and internal distribution of N and P. Harvestable amount of algae along the South coast of Sweden: 43 000 tonnes dry weight Collection take place in the water (within an area 100 m from the coastline) Assumptions of quantities per hectare is based on the present collection performed by the municipality of Trelleborg Fredrik Grndahl, Industrial Ecology, KTH

14. Fredrik Grndahl, Industrial Ecology, KTH

15. Fredrik Grndahl, Industrial Ecology, KTH

16. Fredrik Grndahl, Industrial Ecology, KTH

17. Fredrik Grndahl, Industrial Ecology, KTH

18. Fredrik Grndahl, Industrial Ecology, KTH

19. Fredrik Grndahl, Industrial Ecology, KTH

20. Fredrik Grndahl, Industrial Ecology, KTH

21. Fredrik Grndahl, Industrial Ecology, KTH

22. Mussels Grow on hard substrates down to dephts of 30 m, prefers salinity above 18 PSU. Reduced growth rate, and size compared to the North Sea (3 cm in Baltic Sea). Dominate the Baltic Sea 90 % of the animal biomass growing on hard bottoms Clean water Filter feeding through their gills Feed on phytoplankton Filtration rate: 1-4 liters per hour Fredrik Grndahl, Industrial Ecology, KTH

23. Long line mussel farming Rope wires are held up by floating barrels Mussel lines are hanged from the rope wires The larvae settle on the mussel rigs from where they feed on foodstuffs that naturally exists in the surrounding water. The mussels are harvested through scraping the mussels off the lines by a machine Fredrik Grndahl, Industrial Ecology, KTH

24. Photo; Pia & Karl Norling

25. Kalmarsund, 14 month The biomass after 1 year was 4 kg m-1 or 16 kg for a long line. Fredrik Grndahl, Industrial Ecology, KTH

26. Fritt val av foder Kokt musselktt Vanligt foder

27. Kompostering av musslor

28. Biogas Biogas is formed when volatile solids are broken down anaerobically by methane forming microorganisms. Biogas mainly consists of methane (50-60 volume-%) and CO2 (25-40 volume-%) (hydrogen gas, sulphur-hydrogen, and steam) Formation occurs in four steps Methane formation Sensitive step High concentration of ammonia, phosphorus, potassium, heavy metals, sulphur and certain fatty acids can restrain the sensitive methane forming bacteria Different factors have influence on the biogas production, such as temperature and technique of the biogas production process, pre- treatment of the substrate and chemical composition of the substrate Fredrik Grndahl, Industrial Ecology, KTH

29. System boundaries Fredrik Grndahl, Industrial Ecology, KTH

30. Nutrient removal efficiency Comparison of nutrient contents of the three biomasses, based on living weight Nitrogen content of mussels > 3 times higher Phosphorus content of mussels > 2 times higher Harvest of mussels is most efficient according to nutrient removal Fredrik Grndahl, Industrial Ecology, KTH

31. 2500 En erg y co n ten t [M J/to n n e w w ] 2000 1500 1000 500 0 Algae Reed Mussels Sludge Fredrik Grndahl, Industrial Ecology, KTH

32. Energy demands 600 Energy demands [MJ/tonne ww] 500 400 300 200 100 0 Algae Reed Mussels Fredrik Grndahl, Industrial Ecology, KTH

33. Energy balance 6.E+05 Net energy benefit [MJ/tonne N] 5.E+05 4.E+05 3.E+05 2.E+05 1.E+05 0.E+00 Algae Reed Mussels Fredrik Grndahl, Industrial Ecology, KTH

34. Conclusions Reed has the highest net energy benefit, followed by macro algae. Blue mussels are not suitable for biogas production, but are better than reed or algae when the ambition is to remove nitrogen or phosphorus from the Baltic Sea. Biogas production from reed and macro algae may be important in the future but need further investigations. Fredrik Grndahl, Industrial Ecology, KTH

35. Advantage with Biomanupulation and the production of Biogas Biogas means less CO2 and is thus an important contributor to decreasing climate change. The establishment of wetlands will stimulate biological diversity in the region and will deal with the nutrient load from surrounding farm land. Harvesting of the reed belt will remove the nutrients from the wetland area. Harvesting of macro algae will remove nutrients and heavy metals from the Baltic Sea and improve local beaches for recreation purposes. The removal of Cyanobacteria will remove nutrients from the Baltic Sea, but perhaps the most important contribution is that it will improve recreational value in the region. When the shallow coastal waters are cleansed from oxygen-depleting, decaying accumulated macro algae, large areas will again become available to sustain the growth of juvenile fish.