中文摘要：

选取四季常青苦草、普通苦草、黑藻、狐尾藻和马来眼子菜等5种沉水植物构建表面流人工湿地系统,观察不同沉水植物品种对模拟污水厂尾水中主要污染物的去除效果,筛选出具有最佳去污效果的沉水植物,为优化沉水植物表面流人工湿地系统的处理效果提供理论依据。结果表明：沉水植物表面流湿地系统和无植物表面流湿地系统对各污染物的去除效果均呈现出随着实验时间的延长先波动变化后逐渐趋于稳定的规律。四季常青苦草、黑藻和狐尾藻湿地系统出水COD、TP浓度均低于10 mg·L^-1、0.1 mg·L^-1,分别达到了《地表水环境质量标准》（GB 3838^-2002）Ⅰ和Ⅱ类水标准。除马来眼子菜外,其余4种沉水植物对主要污染物的净化效果存在较大差异,以四季常青苦草的综合净化效果最好,出水COD、TP、NH＋4-N、NO-3-N和TN的平均浓度分别为36.83、0.269、1.17、0.563和3.31 mg·L^-1,平均去除率分别达到41.32%、72.77%、84.29%、79.28%和76.72%。黑藻次之,接着是狐尾藻,而普通苦草的去污效果较差。综合考虑其对模拟城市污水处理厂尾水的深度处理效率,宜选择四季常青苦草作为表面流人工湿地的优选沉水植物。

英文摘要：

Five submerged plants（ evergreen Vallisneria natans,ordinary Vallisneria natans,Hydrilla verticillata,Myriophyllum elatinoides,and Potamogeron malaianus） were used to establish surface flow constructed wetlands（ SFCWs）. The purification performance of the SFCWs for simulated tail water treatment was investigated,and the optimal submerged plant was chosen for the designed system. The purification performance for simulated tail water by SFCWs was indicated by indexes of COD,TP,NH＋4-N,NO-3-N,and TN. The main conclusions of this study follow. The removal efficiency of pollutants in the six SFCWs was unstable at the beginning of the operation but gradually reached stability. The effluent concentrations of COD and TP in the system of evergreen Vallisneria natans,Hydrilla verticillata,and Myriophyllum elatinoides were 10 mg·L^-1and 0. 1 mg·L^-1,respectively. These met the standards of Class Ⅰ and Ⅱ of the Chinese Environmental Quality Standard of Surface Water（ GB 3838-2002）. Except for the one with Potamogeron malaianus,all the other systems showed significant disparity in their capacity for removal of the respective main pollutants in simulated tail water. The evergreen Vallisneria natans system exhibited the best comprehensive purification performance,of which the average effluent concentration of COD,TP,NH＋4-N,NO-3-N,and TN,was 36. 83,0. 269,1. 17,0. 563,and3. 31 mg · L^-1, respectively. Their average removal efficiency reached 41. 32%,72. 77%,84. 29%,79. 28%,and 76. 72%,respectively. In view of its purification performance,the evergreen aquatic plant Vallisneria natans is considered the optimal submerged plant for surface flow constructed wetland systems.