REMOVAL OF NITROGEN AND PHOSPHORUS FROM SEWAGE BY FOUR AQUATIC PLANTS

In this study, Ceratophyllum demersum L., Myriophyllum verticillatum L., Oenanthe javanica (Bl.) DC., and Hydrocotyle vulgaris were selected to treat wastewater with the goal of reducing its nitrogen and phosphorus content. Overall, each of the four selected aquatic plants efficiently remove total phosphorus (TP) and total nitrogen (TN) in sewage. However, the alkaline environment of wastewater (pH 8.7-9.5) is not suitable for growing Hydrocotyle vulgaris, The TP concentration of the test sewage treated by Ceratophyllum demersum L., Myriophyllum verticillatum L., Oenanthe javanica (Bl.) DC., and Hydrocotyle vulgaris meets the standard of surface water type I or II from surface water type IV. However, the TN concentration of the test sewage treated by these four plant species did not reach the standard of surface water type II. High concentrations of TP and TN could have a negative impact on the aquatic plant purification effect, and aquatic plants were more suitable for treating wastewater with lower concentration of TP and TN.