Efficiency of active barriers attaching biofilm as sediment capping to eliminate the internal nitrogen in eutrophic lake and canal.

Three active barrier materials (zeolite, ceramicite and light porous media) were applied for preventing nitrogen (N) release from eutrophic lake sediments. Long term experiment of two different lake sediments were carried out and the effect of zeolite dose was evaluated. The results indicated that about 90%-100% of total N in overlying water was eliminated by using zeolite. While the N removal efficiency by ceramic was lower than that by zeolite, and light porous media present the lowest efficiency of 59%. Long term sediment incubation experiments indicated that two eutrophic sediments were both effective in preventing N release in spite of different release characteristics. Bio-zeolite capping technology was able to effectively inhibit the release of N from the sediment, and the zeolite dose was independently from N removal.