Phytoremediation of fish pond effluent in constructed wetland using three aquatic macrophytes: water lettuce, duckweed, and water hyacinth

Abstract

Fish pond wastewater (effluent) was collected from World Bank SEEFOR empowered fish farm in Umuoko-Aluu, Ikwerre Local Government Area (21o55’ 46”S and 47o22’ 24”W) Rivers State, for a period of four weeks. Within the first two weeks of the 28 days subjection of the macrophytes: water hyacinth (Eichhornia crassipes), water lettuce (Pistia stratiotes), duckweed (Lemna minor) and control (without plant) to fish pond wastewater (effluent), turbidity was reduced by 21-24.9% by the water lettuce, 13.98-27.98% by duckweed and 22.86- 25.71% by water hyacinth. Total dissolved solids (TDS) were removed at 4.75 – 5.06% by water lettuce, 1.16 – 5.51% by duckweed and 4.48% by water hyacinth. Equally, Nitrate-Nitrogen (Nitrate-N) was reduced at 90.48% by water lettuce and 94.74% by duckweed. Foul smell vanished in all the test plant units within the first week. Duckweed (Lemna minor) was adduced the best in terms of the measured parameters and availability.