The objective of this task is developing of a prototype technological solution for obtaining organic fertilizers, such as foliar spray, granulated ferment and vermicompost, from fish processing and other side streams It will provide fish waste processing solution for dispersed communities, where there is no local fish (and other bio)waste treatment facility and where transportation of the waste would not be cost efficient The main treatment is bokashi fermentation and further developments include pelletizing, producing vermicompost and separation of liquid Different pelletizing methods were tested to find an optimal solution that would not damage microbiology but would be strong enough for fish waste processing As a result, extrusion together with hammer mill was found to be most suitable, also because it allows the input material to consist of up to 50 of moisture (compared to the 5 applicable to the matrix method) For drying the pellets, a solar powered tumbler dryer was developed It is an off grid system on a trailer that uses sun power 12 ( volts), which capacity ranges up to 2000 L per month Another main aim has been intermediate products development and testing Bokashi fermentation method was tested on different combinations of side streams and optimal fertilizer formulations were studied.
It was established that fish waste can be bokashi fermented alone as effectively as together with other types of food waste That allows fish waste producers to start fermenting on spot, saving them from the cost of freezing or the problem with rotting.
Fig 1: Testing results for granulation methods
Fig 2: Solar powered tumbler dryer development
Further information: Video
Authors: Nutriloop OÜ
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