Application of floating aquatic macrophytes in treating wastewater from the recirculating aquaculture system of catfish, Clarias macrocephalus

Recirculating aquaculture systems (RAS) present a problem involving the accumulation of NO3-and PO43-atthe end of the culture. The study aimed to identify native aquatic plants ofPistia stratiotes, Lemna minor, Salvinia molesta, and Eichhornia crassipeswith wastewater treatment capabilities in RAS. The catfish, Clarias macrocephalus, weighing 60 g each, were stocked at a density of 65 fish/100L and fed a diet of floating pellets containing 41% crude protein. Pistia stratiotes was the most effective macrophyte for treating wastewater from the catfish culture system during the first 10 days of the experiment. Following treatment with P. stratiotes, the concentrations of CO₂, COD, TAN, N-NO₃⁻, P-PO₄³⁻, and TP in the wastewater decreased by 65.83, 34.28, 40.70, 46.70, 24.56, and 9.16%, respectively, while dissolved oxygen increased by 37.68% compared to the initial concentrations. Further research isrequired to thoroughly comprehend the efficacy and long-term effects of the P. stratiotesin RAS.