Reduction and decontamination effects of Myriophyllum spicatum on livestock wastewater

ObjectivePurification effects of Myriophyllum spicatum on livestock wastewater of different concentra-tions were studied, in order to provide theoretical basis for prornoting the new aquatic plant species in treatment of live-stock residue. MethodM. spicatum was cultivated in wastewater from livestock farm treated by grade 1, 2, 3, 4 and 5 wastewater treatment. During the experiment, the concentrations of ammonia nitrogen(NH4+-N), total nitrogen(TN), to-tal phosphorus(TP), suspended solid(SS), chemical oxygen demand(COD) in wastewater of different levels were mea-sured. The change curves of the indicators were drawn. Pollutant removal rate was calculated by comparing with raw water before experiment. ResultThe concentrations of NH4+-N, TN, TP, SS and COD in wastewater treated by grade 1-5 wastewater treatment decreased sharply at the beginning of the experiment, but this decreasing trend slowed down in later time. At the end of the experiment, the total average removal rate of NH4+-N was the highest, reaching 94.5%, and that of TP was low, which was 74.6%; the total average removal rates of TN, SS and COD were 84.5%, 81.3% and 79.1% re-spectively. ConclusionM. spicatum can effectively remove various pollutants in livestock wastewater such as NH4+-N, TN, TP, SS and COD, and improve water quality environment. It has promising application prospect in treatment and re-mediation of polluted water.