利用3种栽种植物的美人蕉(Canna indica Linn)湿地(M)、狼尾草[Pennisetum alopecuroides (Linn.) Spreng]湿地(L)、苏丹草[Sorghum sudanense (Piper) Stapf]湿地(S)和未栽种植物的对照湿地(CK),研究高、中、低出水口及不同植物对垂直流人工湿地污水净化效果的影响.垂直流人工湿地进水来自常熟农业生态试验站生活污水厌氧池,以间歇式进水方式运行,进水水力负荷为0.15 m3·m- 2·d-1.结果表明:不同出水口位置对NH4+-N(铵态氮)、NO3--N(硝态氮)、COD(化学需氧量)的去除率存在显著性差异.随着出水口位置的降低NH4+-N的去除率显著增加,最大去除率达到98 3%.出水口位置升高NO3--N与COD的去除率则显著增加,高出水口的去除率分别达到-47.4%和64.5%.与中、低出水口处理相比,高出水口的TN(总氮)去除率提高22.5%～27.6%.而对TP(总磷)的去除率恰恰相反,高出水口处理TP去除率比中、低出水口低20.6%～28.9%.3种有植物湿地—美人蕉湿地,狼尾草湿地、苏丹草湿地对NO3--N、TN、TP、COD去除率显著高于未栽种植物的对照湿地,分别提高74.4%～98.6%、11.3%～17.8%、8.60%～16.3%与14.1%～19.0%.3种植物湿地之间对NO3--N、TN,TP、COD去除效果没有显著差异.对NH4+-N的去除效果,美人蕉温地显著低于其他3种湿地.以上结果表明,通过对垂直流人工湿地的出水口位置控制和栽种湿地植物,可以有效地改变污染物的去除效果.%In this study, four different types of engineered vertical flow constructed wetland (VF-CW) - Canna indica Linn wetland (M), Penmsetum alopecuroides (Linn.) Sprcng wetland (L), Sorghum sudanense (Piper) Stapf wetland (S) and control wetland without plant (CK) - were used to determine the effects of outlet positions (high, middle and low position) and plant species on pollutant removal efficiency in rural domestic sewages. Domestic sewages from anaerobic tanks in the Changshu Agro-ecological Experimental Station were intermittently used to irrigate VF-CW at hydraulic loading rate of 0.15 m3m-2d-1. Results showed that the outlet position significantly determined the removal efficiency of NH4+-N, NO3 -N and COD (chemical oxygen demand) in rural domestic sewages. The removal rate of NH4+-N significantly increased with lowering of the outlet position. The maximum removal rate of NH4-N was 98.3%. However, the removal rate of NO3~-N and COD significantly decreased with lowering of the outlet position. The removal rates of NO3~-N and COD of the highest outlet were -47.4% and 64.5%, respectively. The removal rate of total nitrogen (TN) of the high outlet increased by 22.5%~27.6% compared with that of the middle and low outlets. On the contrary, the removal efficiency of total phosphorus (TP) of the high outlet was 20.6%~28.9% lower than that of middle and low outlets. Compared with the control treatment (CK), the removal rates of NO3~-N, TN, TP and COD in VF-CW with C. Indica, P. Alopecurvidesand S. Sudanense significantly increased by 74.4%~98.6%, I1.3%~17.8%, 8.60%~16.3% and 14.1%~I9.O%, respeclively. However, no significant differences were noted among VF-CWs with three plant species regarding the removal of NCV -N, TN, TP and COD. In term of the removal rate of NH/-N, C. Indica wetland performed significantly less than the other plant species VF-CWs. These results suggested that pollutant removal efficiency improved by controlling outlet position and growing plants in VF-CW systems.
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