Duckweed Bioconversion and Fish Production in Treated Domestic Wastewater

Abstract

We evaluated the bioconversion of domestic wastewater into protein biomass through duckweed based ponds and fish farming in a pilot recirculating system. The average duckweed wet biomass yield obtained during the experimental period was 4.96 kg/m² (1.3 kg dry matter; 63 g/m²/day), with crude protein and fiber content of 38.03% and 16.17%, respectively. Tilapia final average weight, feed conversion rate, and specific growth rate when fed pelletized duckweed were similar to values with commercial feed. Duckweed production removed 30.8% and 28.7% of ammonia and phosphate, respectively, from stabilized domestic wastewater.

KEYWORDS:

• Lemna
• tilapia
• effluent
• reuse
• alternative dietary source
• production costs