Frederike Gröner, Christin Höhne, Mathias Kunow and Werner Kloas IGB Berlin. Technical instructions and potential research questions

Transcription

1 Frederike Gröner, Christin Höhne, Mathias Kunow and Werner Kloas IGB Berlin Technical instructions and potential research questions

2 Introduction to Aquaponic aqua = aquaculture ponic= hydroponic rearing tank solids removal biofilter hydroponic reservoir Optimal aquaponic arrangement accoding to Rakozy and Hargreaves (Integration of Vegetable Hydroponics with Fish Culture: A Review)

3 Why land-based integrated aquaculture? Minimize interactions between water quality and cultivated organisms Optimal use of existing resources nutrient rich effluents of fish tanks are used to fertilize growing plants (aquaponic)

4 Aim Gain a sustainable value chain by closing water and nutrient cycles in the project area, leading to water security as well as food availability and further income options.

5 Potential integrated nutrient cycle based on the INNOVATE concept in Itacuruba, Pernambuco spray irrigation in agriculture aquaculture hydroponic AQUAPONIC Green Liver agriculture (semi-aquatic plants) Itaparica Reservoir local people biogas eutrophication agriculture diatomeen(/green algae cyanobacteria industry

6 Aquaponic model system (1) Volume chosen to demonstrate self-supply option for local population (2 m³ total water volume to rear about 100 kg tilapia with optimal conditions) All mandatory elements included, up- (and down-)scaling of the pilot facility is feasible and volumes can be adapted to demand

7 Aquaponic model system (2) The aquaponic model system consists of two fish tanks (0,5 m³ each), a mechanical filter unit (sedimentation tank 1 and 2) followed by a biological filter (trickling filter) and a hydroponic unit consisting of two plant channels. Trickling Filter Fish tanks Sedimentation tank 2 Sedimentation tank 1 Plant channels Plant water supply with float gauge

8 Aquaponic model system (3) Water Flow: Trickling filter Sedimentation tank 2 Sedimentation tank 1 Plant channels Fish tank 1. Effluents of the fish tanks flow into sedimentation tank 1 followed by tank 2, where flow velocity is highly reduced. 2. Afterwards, the water is pumped through the trickling filter (filled with biocarrier), where nitrification takes place and water oxygenates. 3. Water flows down into a storage tank and can be used to provide treated water for the fish tanks. 4. Before passing the trickling filter, nutrient rich water can be redirected to a water storage tank for the plant channels. A float gauge then regulates water flow into the plant channels demand-based. Water cannot flow back into the fish tanks.

9 First commissioning (1) 1. Fill up with water (tap water* 1 or water from the Green Liver System* 2 or the Itaparica Reservoir* 3 ): Start filling water into the Sedimentation tank 2, where the pump is located. Switch on the pump if this sedimentation tank is full and wait until the whole system is filled with water. The sprinkler of the trickling filter should start to run. Check for possible leaks. (Let the system run for 2-3 days, so that the chlorine that may be in the tap water can evaporate.) * 1 Disadvantage: Brazilian tap water contains chlorine. If you take this let the chlorine evaporate for 2-3 days. Just do nothing and wait before you put the first feed inside. Advantage: It s mainly free of organisms. * 2 Disadvantage: May contain fish fry or fertilized eggs because many fish live in there. Make sure you don t have them in your system. Contains algae and other plants. Advantage: No chlorine. Filtered by the Green Liver System. * 3 Disadvantage: May contain fish fry or fertilized eggs because many fish live in there. Make sure you don t have them in your system. Contains algae and other plants. Advantage: No chlorine.

10 First commissioning (2) 2. You may insert plants into the plant channels. Do not take seeds, but seedlings which have already roots. Plants should grow on soil-free material like mineral wool or coconut fiber! 3. Measure nitrite and nitrate. 4. Take 200g fry feed (more expensive; powder) or fattening feed (cheaper; pellets: before usage let them soak with water so that they are viscous) and put it into the fish tanks every day. 5. Water monitoring over 2 weeks (more or less): Measure nitrite and nitrate. First there will be a high increase, because there are no bacteria for nitrification. After about 14 days there should be a decrease in nitrite which indicates that bacteria have settled on the small plastic bodies (biocarrier) inside the trickling filter. Now the filter works properly. 6. Always compensate for water losses due to evaporation. Use chlorine free water. Examples of plastic bodies in a biological filter

11 First commissioning (3) 7. When the filter works and the water parameters have stabilized: You may insert the first fish Things you have to pay attention to when inserting fish (1):! The amount of fish depends on the amount of feed you put into the system. BUT the amount of feed you can put into depends on the performance of the filter!! At the moment, the trickling filter is half filled (2m 2 ) with plastic bodies, for bacterial growth. The area on which they can settle is about 200m 2 (1m 3 plastic particles ~ 100m 2 area). Under optimal conditions (e.g. T=25 C, optimal water parameters) you may put 1.5kg food inside. Now you calculate how many fish (kg) can feed on 1.5kg food. Therefore you often have tables, e.g.: Fish size (g) Water temperature ( C) ,72 1,16 1,74 2,17 2,61 2,9 2,61 2, ,58 0,93 1,39 1,74 2,08 2,32 2,08 1, ,46 0,74 1,11 1,39 1,67 1,85 1,67 1, ,37 0,59 0,89 1,11 1,33 1,48 1,33 1,19 Feed recommendation: Amount of feed (kg) per day for 100kg of fish n/tilapia/6-mm

12 First commissioning (4) Things you have to pay attention to when inserting fish (2):! ATTENTION: In the beginning you put only 200g food inside (Do you remember?). You should not suddenly put 1.5kg food! Otherwise your nitrite will increase because the bacteria need time for growing and adjusting to the higher nutrient level. And your newly inserted fish may die.! So you gradually increase the amount of food from 200g to 1500g over weeks (maybe months) and adjust the fish stock. Monitor the water parameters.! If the water gets too hot: You may have to set up a sun protection cover over the water tanks. Otherwise the fish may get problems with oxygen level. If it is still too hot for tilapia you may think about another fish species like Arapaima gigas.

13 Potential research questions 1) Potential hydroponic plants should be identified with special interest for the local market (e.g. tomatos, onions ) 2) Potential fish species (e.g. Arapaima gigas) 3) Fish size that is proper for the system 4) Potential of upscaling the plant channels (more than 2 channels possible) 5) Upgrading the biological filter by putting more plastic bodies inside (until 4m 3 )

14 Potential research questions 6) Examination of evaporation and investigation of solutions for decrease 7) Maintenance costs and productivity could be examined 8) Nutrient load of fish tank waste waters could be investigated

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