Environmental Remediation of Tilapia Aquaculture Wastewater Using Ceratophyllum demersum and Lemna minor

Abstract

Two aquatic macrophytes, Ceratophyllum demersum and Lemna minor, were used in aquaculture wastewater treatment. Tilapia fish (Oreochromis niloticus) with total body weight of 50-60 g were placed in 60 L aquaria. Four treatment groups were included: control (no plant treatment, depended on artificial filtering for purification), Lemna minor (Lm), Ceratophyllum demersum (Cd), and mixed plants group (Lm+Cd). Each group had three replicates (5 fish/replicate). The experiment was conducted for 4 weeks. Physicochemical parameters of aquaculture wastewater including pH, total dissolved solids (TDS), conductivity, turbidity, dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total phosphorous (TPO4), nitrate (NO3), nitrite (NO2), and ammonia were determined. The results reflected more effective removal of pollutants from fish aquaria by both plants than that by the artificial aeration/filtering. The effectiveness of pollution removal was higher in Cd group > Lm > Lm+Cd, compared to the control. This order of phytoremediation was confirmed by improvements in tilapia fish health status including liver function (AST, ALT, albumin), kidney function (creatinine, urea, uric acid), in addition to other nutritional and hematological parameters. It could be concluded that the phytoremediation using C. demersum is ecofriendly and effective in removing contaminants from Tilapia aquaculture wastewater and therefore, it is recommended to be applied in tilapia farms.