Abstract:
The aquaculture sector in Africa has great potential for growth; however, it faces several challenges, one of them
being the scarcity of clean water. This prompts the need for water recycling. The present study was conducted to
investigate the effects of rearing Nile tilapia (Oreochromis niloticus) using municipal wastewater treated with
membrane bioreactor (MBR) technology. A total of 270 Nile tilapia fingerlings (0.15±0.05 g) were reared in
three treatment groups in triplicate. There were 2 treatments, including; MBR treated wastewater and
stabilization pond treated wastewater (maturation pond), while the municipal tap water was used as the control.
The growth performance (weight and length) of the fish was monitored over a 24-week period. After the
experimental period, the biochemical composition of the fish muscle was analysed using standard AOAC
methods. The results showed that the highest weight gain, length gain, survival rate, and specific growth were
obtained in the fish in the control followed by the MBR treatment. Additionally, the crude protein, as well as the
crude fiber and dry matter, were significantly higher in the fish in the maturation ponds at 23.10%, 0.29%, and
25.35%, respectively, while the crude ash was highest in the MBR at 1.22%. Results also showed that the MBR
and maturation pond treatments meet the permissible levels for BOD, COD, NH4, and NO3 for water to be used
in aquaculture. The bioaccumulation of heavy metals in the fish was mainly from the feed, with copper being the
highest contaminant at 1.75 mg/100 g. In conclusion, both the MBR and maturation pond treated wastewater are
viable for use in the rearing of Nile tilapia without adverse effect on the growth. However, MBR treatment
showed better growth performance, suggesting that it could be used to increase productivity in fish farming.
