Comparative Performance of Water Hyacinth (Eichhornia crassipes) and Water Lettuce (Pista stratiotes) in Preventing Nutrients Build-up in Municipal Wastewater

Studies on removal of nutrients from domestic wastewater using water hyacinth (Eichhornia crassipes) and water lettuce (Pista stratiotes) were conducted. The plants were grown in 68 L of wastewater with 21-day retention period in fiber-glass tanks with another similar tank as control. Eichhornia crassipes performed better than P. stratiotes in reducing the concentrations of nitrate-nitrogen and ortho-phosphates while P. stratiotes performed better than E. crassipes in reducing the concentrations of ammoniacal-nitrogen (NH4-N) and nitrite-nitrogen. On average, E. crassipes reduced the NH4-N concentration by 72%, P. stratiotes reduced the concentration by 83% and the concentration in the control was reduced by 95%. On average, E. crassipes reduced the phosphate concentration by 55%, P. stratiotes reduced the concentration by 60% and the concentration in the control increased by 28%. Algae significantly reduced the concentration of NH4-N.