Author:
Sharylo Dmytro,Kovalenko Vasyl
Abstract
Modern technologies of cultivation of hydrobionts in recirculating aquaculture systems require significant volumes of biological filters (about 10% of the total volume of the fish farming system), which makes it relevant to search for new fillers that would have a larger specific surface area for colonisation by microorganisms than conventional polymer filling, which would reduce the size of the biofilter and, accordingly, the cost of water and electricity for the production of aquaculture products. The purpose of the study was to evaluate the effectiveness of using highly porous foamed glass as a biofilter filler, compared to conventional floating polymer loading. To achieve this goal, a systematic approach to a particular problem and general scientific research methods were used: experiment, modelling, comparison, analysis, synthesis, and generalisation. The model experiment was conducted in the educational and scientific laboratory of the Centre for Aquatic Bioresources and Aquaculture of the National University of Life and Environmental Sciences of Ukraine. Based on the results of the experiment, it was found that the test material has a significantly higher bio-cleaning potential than polymer loading for biofilters. The maximum concentration of ammonia in the water of the recirculating aquasystem for growing sturgeon fish, which is oxidised by a biofilter with 1 dm3 of foamed glass as a filler (32 mg/dm3) during the day, was determined. Calculations of the potential biological load during the cultivation of hydrobionts in the aquasystem were carried out, and it was found that 10 md3 of this filler maintains an optimal level of nitrogen content when growing sterlet fish planting material with a planting density of 41.6 kg/m3 or 84.8 kg/m3 of commercial fish. It is determined that the required volume of the biofilter is reduced by 4.55 times, and the cost of water and energy supply for the operation of the recirculating aquasystem will also be proportionally reduced. Thus, the use of foamed glass as a filler for biofilters of recirculating aquasystems will increase the profitability of fish production at aquaculture enterprises
Publisher
National University of Life and Environmental Sciences of Ukraine
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