Study on purification performance of nitrogen and phosphorus in landscape water by enhanced combined ecological floating bed

Abstract

Taking Hornwort, Hydrilla verticillata, Iris, Calamus and Loosestrife as the research objects, under the static water condition of a university landscape lake in Xi’an, the combined ecological floating bed composite system of emergent plant submerged plant matrix microorganism enhancement was constructed to carry out the simulated hydroponic experiment for the investigation of the absorption to nitrogen and phosphorus in the water and the purification ability of the ecological floating bed composite system. The results showed that: (1) The best group of combined plants in the landscape lake water was calamus + Hydrilla verticillata, and their removal rate on Total nitrogen, Total phosphorus, Chemical oxygen demand, and ammonia nitrogen are 92.72%, 81.26%, 68.55%, 93.69% respectively. (2) Under the composite floating bed matrix system, the optimal substrate group and ratio are ceramsite and vermiculite (1:1), and their removal rates on Total nitrogen, Total phosphorus, Chemical oxygen demand, and ammonia nitrogen are 61.68%, 86.96%, 79.65%, and 78.12% respectively. (3) The best residence time of AM bacteria in the enhanced combination floating bed was 25 days, and the removal efficiency of total nitrogen and total phosphorus was 67.31% and 93.20% respectively.