Study On The Denitrification Mechanism With (Nh4+)-N-15 Isotopic Tracer Method In The Zeolite Vegetation Concrete

N-15-labelled NH4+ was used to study the denitrification mechanism of the zeolite vegetation concrete in the eutrophication water. The removal ratio of NH4+ was 99% by the zeolite vegetation concrete after incubation of 6 days. The experimental results showed that 14(+/- 2)% of NH4+ was adsorbed by the zeolite, 26(+/- 5)% of NH4+ was transferred into the plants to form the organic nitrogen, 35(+/- 10)% of NH4+ was retained in the soil due to the adsorption and the absorption by the mineral and microorganism, and the left wasn't detected. The plant paspalum notatum flugge exhibited a high NH4+ uptake rate of 14mg N kg(-1)d(-1). Our results suggested that zeolite vegetation concrete functioned effectively as a sink for NH4+ in treating eutrophication water.