1. Grouper Farming in Recirculated Aquaculture Systems
By M.Sc. Tom Serholt

2. Basic Principles of the Recirculated Grouper Farming System

3. Project Presentation Mechanical Filtration Biological Filtration
Bacteriological Filtration

4. Example of Recirculated Wastewater Treatment

5. Recirculation Principles

6. Excretion products and uneaten feed pellets

7. Particular Waste Products
Dissolved Waste Products
Ammonia/Ammonium

8. Mechanical Filtration

9. Mechanical Filters

10. Filtration Principle

11. Particular Waste Products
Dissolved Waste Products
Ammonia/Ammonium
(Removed by mechanical filtration)
NH4+ 

12. Project Presentation Mechanical Filtration Biological Filtration
Bacteriological Filtration

13. CO2 Stripping and areation (O2)

14. Particular Waste Products
Excrements
Feedpellets
Dissolved Waste Products
Ammonia/Ammonium
(Removed by mechanical filtration)
(Removed by mechanical filtration) O2
NH4+ 

15. Pump Sump

16. Bio Filter Pumps

17. Submerged Filter

18. Submerged Filter
Fixed Film Technology
BIO-BLOK 150

19. Convertion of Amonia to nitrite by Nitrosomonas bacteria sp.

20. Particular Waste Products
Dissolved Waste Products
Ammonia/Ammonium
(Removed by mechanical filtration)
(Convertion of ammonia to Nitrite)
Nitrite O2
NH4+ 
NO2- 

21. Trickling Filter

22. Trickling Filter
Fixed Film Technology
BIO-BLOK 200

23. Convertion of Nitrite to Nitrate by Nitrobacter bacteria sp.

24. Particular Waste Products
Excrements
Feedpellets
Dissolved Waste Products
Ammonia/Ammonium
(Removed by mechanical filtration)
(Removed by mechanical filtration)
(Convertion of ammonia to Nitrite)
Nitrite
(Convertion of Nitrite to Nitrate)
Nitrate O2 O2
NH4+ 
NO2- 
NO3- 

25. Convertion of Nitrate to Nitrogen by anaerobic bacteria sp.

26. Particular Waste Products
Excrements
Feedpellets
Dissolved Waste Products
Ammonia/Ammonium
(Removed by mechanical filtration)
(Removed by mechanical filtration)
(Convertion of ammonia to Nitrite)
Nitrite
(Convertion of Nitrite to Nitrate)
Nitrate
(Convertion of Nitrate to Nitrogen)
Nitrogen O2 O2
Carbon source
NH4+ 
NO2- 
NO  N2

27. Backwash System

28. Overview Ammonia  Nitrite  Nitrate  Nitrogen
Submerged- and trickling filter Denitrification filter
Ammonia  Nitrite  Nitrate  Nitrogen
Aerobic conditions Anaerobic conditions
O O Carbon source
NH4+  NO2-  NO  N2

29. Particular Waste Products
Particular Waste (Removed by mechanical filtration)
Dissolved Waste Products
Ammonia/Ammonium (converted in the submerged filter)
Nitrite (converted in the trickling filter)
Nitrate (converted in the denitrification filter)
Nitrogen (emmission to the atmosphere)
Furthermore BOD is converted into Water and CO2

30. Project Presentation Mechanical Filtration Biological Filtration
Bacteriological Filtration

31. Bacteriological Filtration
In order to reduce the bacteriological ”pressure”, the following technologies can be used:
UV Filtration
Ozone
Membrane Filtration

32. Propeller Pumps & UV-Filters

33. Propeller Pumps

34. UV-Treatment

35. Principle of UV Filtration

36. Project Presentation Mechanical Filtration Biological Filtration
Bacteriological Filtration

37. Oxygenation

38. Production Figures:
500 fish harvested per day with an average weight of 700g. Per fish.
Size of fingerlings: 30g. Per fish.
Size of fish at harvest: 700g. Per fish.
Growth per day: kg. Fish per day.
FCR (Feed Convertion Rate): 1,5
Fish Feed fed per day: 503kg. Per day
Feeding Rate: 1,2%

39. Production Figures:
500 fish harvested per day with an average weight of 700g. Per fish.
Standing Stock kg. Fish (total)
Temperature: Degrees Celcius
Daily ”make up” water: 156m3 of water
Circulating water Volume: m3 water per hour

40. Thank You