Abstract

Vertical flow constructed wetland nitrogen concentration vertical distribution in the simulation system

Author(s): Xing-guan Ma, Tao Jiang, Qiu-ju Zhao, Yi-da He, Dan Liu

The research under different working conditions,the vertical flow constructed wetland simulation system packing various forms of nitrogen in the vertical distribution of concentration,by measuring the depth of denitrification effect,to determine the effective height of packing. Use with zeolite ceramsite and packing,willow food for wetland plant four units of vertical flow constructed wetland system. 1#:ceramsite,growing plants,aeration; 2#:zeolite,no plant,no aeration; 3#:zeolite,plant,no aeration; 4#:zeolite,a plant,aeration. Four devices were separately measured the depth of oxygen,nitrogen concentration and conversion rate. Four units in the depth of the packing for 20 to 30 cm DO drops rapidly, to DO to achieve the minimum 50 cm, respectively is 1.55 mg/L,0.71 mg/L, 0.68 mg/L,5.39 mg/L.1#,4# processing unit average removal rate of TN were 27.9%,25.3%,35.1%,19.6%. The four processing unit of NH4 +-N average conversion rate were 87%,89%,89.8%,91.6%;Of NO3 --N in the system did not decrease,accumulation. The simulation system,the working condition of 3# for nitrogen removal effect is best.3# unit transformation of NH4 +-N and TN removal at a depth of 30 cm maximum,so are made valid by means of the zeolite packing of artificial wetland are 30 cm deep. NO3 -_N concentrations in the four units is higher,the main reason is lack of carbon source,the denitrification reaction is weak,cause the accumulation of NO3 -_N,appropriate supplementary carbon source for denitrification reaction.