Cristina Moisescu, Mirela Iordan, Cristina Alina Dumitrache, Ioan I. Ardelean
Full Text PDF | activated sludge, bacterial denitrification, microbial consortia, recirculating aquaculture system.
In Recirculating Aquaculture System (RAS) the water effluent from fish tanks is reused after cleansing mainly with respect to organic substances, nitrate (NO3-), nitrite (NO2-), ammonium (NH4+) and phosphate (PO4-3) ions. One of the most used and promising cleansing techniques in modern RAS is the biological treatment of wastewaters performed by denitrifying bacteria which can convert the NO3- to N2. In this study we estimated the aerobic denitrifying performances of different microbial consortia isolated from various sources, feasible to be further used in RAS. The kinetics of NO3- consumption in either batch or discontinuous conditions, on synthetic culture media with acetate or ethanol as sole carbon source and nitrate as the main final electron acceptor, has been characterized. The experimental data showed that the selected microbial populations can clean water with efficiencies between 86% to 100%, matching the requirements of international laws and making them suitable for employment in wastewater treatment in RAS.