Globally, rainbow trout (Oncorhynchus mykiss) stands out as an important aquaculture species, accounting for around one seventh of total production in the EU-28 and a quarter of all farmed salmonid species worldwide. The sector's growth potential is increasingly constrained by factors such as limited access to freshwater and stricter environmental regulations. To overcome these limitations, recirculating aquaculture systems (RAS) have been developed as a viable and environmentally friendly alternative. In these closed recirculation systems, water is continuously treated, and water consumption is reduced by up to 99% compared to conventional methods. This efficiency is achieved through advanced mechanical and biological filtration, which ensures optimum water quality for fish growth. The sludge from the pilot scale RAS of the University of Ljubljana was characterized and treated by anaerobic digestion in order to assess the energy potential of this effluent. The tests were performed in batch conditions at 38°C, according to the Biochemical Methane Potential (BMP) standards. Digestate from a commercial scale, 1MWe biogas plant fed with dairy manure and silages was utilized as inoculum in the process. Two different ratios of VSinoculum/VSsubstrate were adopted, 10 (thesis 1) and 5 (thesis 2). The methane yields of the two theses resulted almost identical, indicating that the process was capable of reaching the maximum BMP with both inoculum/substrate ratios. The methane yield referred to the VS content resulted of 576.1 NL/kgVS for thesis 1 and 576.5 NL/kgVS for thesis 2, to indicate a relevant energy potential of this effluent.
Anaerobic Digestion of Sludge from Recirculating Aquaculture Systems (RAS) Trout Production
Chiumenti A.
;da Borso F.;Owono Owono B.;Tulli F.;Paolin D.;Cardinaletti G.
2025-01-01
Abstract
Globally, rainbow trout (Oncorhynchus mykiss) stands out as an important aquaculture species, accounting for around one seventh of total production in the EU-28 and a quarter of all farmed salmonid species worldwide. The sector's growth potential is increasingly constrained by factors such as limited access to freshwater and stricter environmental regulations. To overcome these limitations, recirculating aquaculture systems (RAS) have been developed as a viable and environmentally friendly alternative. In these closed recirculation systems, water is continuously treated, and water consumption is reduced by up to 99% compared to conventional methods. This efficiency is achieved through advanced mechanical and biological filtration, which ensures optimum water quality for fish growth. The sludge from the pilot scale RAS of the University of Ljubljana was characterized and treated by anaerobic digestion in order to assess the energy potential of this effluent. The tests were performed in batch conditions at 38°C, according to the Biochemical Methane Potential (BMP) standards. Digestate from a commercial scale, 1MWe biogas plant fed with dairy manure and silages was utilized as inoculum in the process. Two different ratios of VSinoculum/VSsubstrate were adopted, 10 (thesis 1) and 5 (thesis 2). The methane yields of the two theses resulted almost identical, indicating that the process was capable of reaching the maximum BMP with both inoculum/substrate ratios. The methane yield referred to the VS content resulted of 576.1 NL/kgVS for thesis 1 and 576.5 NL/kgVS for thesis 2, to indicate a relevant energy potential of this effluent.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
