Environmental and sustainability aspects of a recirculating aquaculture system

This article presents some new exergy-based parameters for Recirculating Aquaculture System (RAS) for Black Sea trout (Salmo trutta labrax) at the Trabzon Central Fisheries Research Institute, Turkey. On the basis of the actual data employed, some environmental and sustainability aspects of the RAS are parametrically studied in terms of exergy parameters. In this regard, the exergetic parameters, such as exergetic efficiency, waste exergy ratio, exergy recoverability ratio, exergy destruction ratio, environmental impact factor, and exergetic sustainability index are proposed and investigated. The results show that mainly based on the operating principle of the RAS, increasing waste exergy ratio decreases the exergetic efficiency and exergetic sustainability index. However, any increase in waste exergy ratio results in an increasing environmental impact of the RAS. Thus, the RAS requires much more improvement because of the higher environmental impact factor and lower exergetic sustainability index during the operating the system. This is evident from the exergy recoverability ratios ranging from 0.27 to 0.37. Furthermore, studying these parameters indicates how much improvement is possible for the RAS to achieve better sustainability.