Enhanced purification of eutrophic water by microbe-inoculated stereo floating beds

This study was conducted to investigate the feasibility of using floating beds of tall fescue plants (Festuca arundinacea) inoculated with denitrifying polyphosphate accumulating microorganisms (DPAOs). In the presences of DPAOs, tall fescue showed greater removal of NH₄⁺-N, NO₃⁻-N, total N (TN), and orthophosphate (ortho-P) after a 20-day treatment. The average removal rates were 86.32%, 93.60%, 90.12%, 72.09%, and 84.29%, respectively, for NH₄⁺-N, NO₃⁻-N, TN, total P (TP), and ortho-P. Tall fescue plants grew well on the floating beds and the average growth rate was approximately 5.4 g DM m⁻²·d⁻¹. Tall fescue plants, being rich in crude potein, Ca, Mg, Fe, and Mn, can meet the daily feed requirements of livestock and poultry and were found safe to be used as animal feed.