3种湿地植物对农田沟渠水体氮、磷的消减作用

由于农业生产过程中过量施放化肥，农田氮、磷流失从而对周边水体产生一定的面源污染。为探讨水生植物种植对农田排水沟渠中流失氮、磷的吸附拦截效果，在农田沟渠内种植水芹Oenanthe javanica，石菖蒲Acorus tatarinowii和刺苦草Vallisneria spinulosa，测定植物对农田沟渠内氮、磷营养物质的消减作用。结果表明:通过种植植物，沟渠内总氮去除率为56.18%~74.58%，铵态氮去除率为36.23%~59.33%，硝态氮去除率为34.35%~66.88%，总磷去除率为44.38%~76.35%；随水流路径的延长沟渠中氮、磷的质量浓度均呈递减趋势；随时间增加，沟渠内各采样点氮、磷质量浓度呈明显下降趋势。表明水芹、石菖蒲和刺苦草对农田沟渠中氮、磷具有较好的去除效果，可应用于湖泊及其周边等污染水体的生态修复治理。

Removal of nitrogen and phosphorus in farmland ditches using three aquatic plants

Due to heavy fertilizer application and improper management in the process of agricultural production, large amounts of nitrogen (N) and phosphorus (P) in farmlands have been lost and have affected surrounding water bodies. To study the effect of aquatic plants on the absorption of N and P in farmland drainage ditches, Oenanthe javanica, Acorus tatarinowii, and Vallisneria spinulosa were planted in ecological ditches. In June 2015, the change of N and P content with the water flow in the ditch were estimated through field investigation and laboratory bioassay. Results showed that plants in ditches had a total nitrogen (TN) removal rate of 56.18% -74.58%, an ammonium (NH₄+) nitrogen removal rate of 36.23% -59.33%, a nitrate (NO₃-) nitrogen removal rate of 34.35% -66.88%, and a total phosphorus (TP) removal rate of 44.38% -76.35%. From the point of view of the monitoring sites, the concentration of N and P in ditches decreased overall with a prolonged water flow path. Also, with an increase in time, the concentration of N and P in different sampling sites showed a strong downward movement. Thus, this study could be a guide for ecological restoration projects in lakes or other water bodies with aquatic plants.