Abstract:By constructing multi-surface flow wetland,the effects of wetland system were examined and the control of rural non-point source pollution around Poyang Lake was discussed.Results showed that the total reductions of COD,TP,NO-_3—N,and NO-_2—N in the wetland system were 608.46,3.22,8.14,and 0.62 kg/a and the reductions of COD,TP,NO-_3—N,and NO-_2—N per hectare were 3976.83,21.04,53.21,and 4.05 kg/(hm2·a),respectively.The removal rates of COD,TP,NO-_3—N,and NO-_2—N in the wetland system were 48.9%,73.5%,58.7%,and 54.7%,respectively,and the COD and TP removal mainly occurred in the first reed wetland.Because the constructed wetland had a strong function of recovering oxygen,denitrification of NO-_3—N was limited.In order to enhance NO-_3—N removal rate,we discussed the mechanisms of nitrification and denitrification in wetland system and put forward the effective measure that part of the wastewater drained directly into the end of three wetlands and the end of three wetlands changed into subsurface flow wetland.In short,the wetland system not only provided a technical foundation for the control of rural non-point source pollution around Poyang Lake,but also afforded a demonstration for other lakefronts.