Research on the annual changes of nitrogen removal efficiency in a combined ecological floating bed system

Abstract:

A new type of ecological floating bed system that combined emergent aquatic plant, submerged plant and biofilm was developed in this study.The purification effect of the system was determined all the year round. And the kinetics of TN and NH₄⁺-N treatment,curtailing model and contribution rate of different media were also studied.The results indicated that the new ecological floating bed system has high nitrogen removal rate,of which the contribution rate of the upper layer accounted for 15.6%±1.2%, the middle layer accounted for 37.6%±2.2%, and the lower layer accounted for 23.8%±1.8%. It shows that the middle layer played a major role in nitrogen removal.During the period,the highest removal rate of NH₄⁺-N and TN was over 93% and 94%, respectively.Compared with control, NO. 5 pool wich contains both the middle layer and lower layer got the highest nitrogen removal rate (P<0.10). Curtailing models of NH₄⁺-N and TN were calculated by kinetics curves. The present study provided technical support to the application of the ecological floating bed system in the future.