四种挺水植物生理生态特性和污水净化效果研究

采用人工气候室水培系统以人工污水培养慈姑(Sagittaria trifolia)、花皇冠(Echinodorus berteroi)、菖蒲(Acorus calamus)和芦苇(Phragmites australis) 4种挺水植物，比较它们的根和地上部分生物量、根长、根寿命、根孔隙度、根径向泌氧量(ROL)、光合作用等生理生态特性及对总氮(TN)、总磷(TP)、化学需氧量(COD)的去除效果。结果表明，ROL与根孔隙度、光合速率、地上生物量呈显著正相关(P<0.05)，与根长极显著正相关(P<0.01)；TP的去除与光合速率、COD的去除与ROL显著正相关; TN的去除与生物量极显著正相关(P<0.01)，但与根生物量和地上部分生物量的比值(根茎比)显著负相关(P<0.05)。慈姑和花皇冠拥有庞大生物量和发达的根系，根孔隙度、ROL和光合作用等生理指标较高，在水培系统中的污水净化效果接近甚至优于菖蒲和芦苇，是构建人工湿地的优良植物。

Eco-physiological Characteristics and Decontamination Efficiency of Four Emergent Macrophytes

Four emerged Macrophytes, Sagittaria trifolia, Echinodorus berteroi, Acorus calamus and Phragmites australis, were cultured with synthetic wastewater in phytotron hydroponic system. The eco-physiological characteristics, such as biomass, root length, root lifespan, root porosity, root radial oxygen loss (ROL), photosynthesis and decontamination efficiency of total nitrogen, total phosphorus and COD were compared. The results showed that ROL positive correlated to root porosity, photosynthetic rate and biomass (P<0.05), and significant to root length (P<0.01). The removal rate of TP and COD correlated to photosynthetic rate and ROL, respectively, while the removal rate of TN significantly positive correlated to biomass (P<0.01), and it is negative to root/shoot ratio. Compared with A. calamus and P. australis, S. trifolia and E. berteroi had large biomass, well-developed root system, relatively high physical index in root porosity, ROL and photosynthesis, and a closer or even better decontamination efficiency. It suggested that S. trifolia and E. berteroi might be excellent species for constructing wetlands.