中文摘要：

以图们江下游的塔头苔草、大穗苔草和芦苇三种典型湿地植物为试材,研究三种植物对当地污水的净化效果。结果表明：三种植物中塔头苔草的综合去污能力最强,其次为大穗苔草和芦苇,这与三种湿地植物根际土壤微生物的数量具有极显著的相关性。另外,植物对污染物的去除率与水力停留时间（HRT）有关：当HRT=3d时,化学需氧量（COD）的去除率达到最大值,而后去除率趋于稳定;随着停留时间的增加,系统中溶解氧（DO）的含量逐渐减少,使得氨氮（NH3-N）的去除率也逐渐降低,但各植物系统中总氮（TN）去除率却呈现逐渐上升的趋势;当HRT=5d时,对磷酸盐（P）去除率达到最大值。

英文摘要：

The sewage purification effects of three types of wetland plants, including Carex heterolepis,Carex rhynchophysa, and Phragmites australis in the downstream of Tumen river, were analyzed in this paper. The results showed that Carex heterolepis has the highest ability of comprehensive decontamination among the three plants, followed by Carex rhynchophysa and Phrag- mites australis. The finding was in significant correlation with the number of rhizosphere microbes of the three types of wetland plants. Moreover, the decontamination rates for the plants were correlated to the hydraulic retention time （HRT）. When HRT was 3 days, the removal rate of COD reached its maximum value and then tended to be stable. With the increasing of HRT, the content of dissolved oxygen （DO） in the system decreased gradually, which resulted in the decreasing of removal rate of ammo- nia nitrogen （NH3-N） but the increasing of removal rate of total nitrogen （TN） in each plant system. When HRT was 5 days, the removal rate of phosphorus reached its maximum value.