沉水植物水槽对农村水体净化效果与机制的模拟

实验设计中试水槽装置,模拟研究2种沉水植物轮叶黑藻(Hydrilla nerticillata)和苦草(Vallisneria natans)对农村水体的净化效果,并探讨沉水植物在水体氮、磷去除中的作用.结果显示,沉水植物系统均能显著降低水体中总氮、铵态氮、硝态氮和磷酸盐浓度,去除率分别达到50.5%、84.4%、41.9%和64.6%,且轮叶黑藻组选择20 g/m2,苦草组选择40 g/m2为适种密度.水体流经各串联单元时氮、磷去除负荷存在显著差异,其中总氮、硝态氮、磷酸盐浓度在有植物单元高于无植物单元,铵态氮浓度相反,结合单元内溶解氧浓度、硝化与反硝化细菌总数表明,有植物单元可显著发生反硝化作用,无植物单元可显著发生硝化作用,有无植物串联单元更有利于氮的去除.

Simulation on rural water purification effect and mechanism with submerged macrophytes' sink

This experiment examined the purification effect of two submerged plants (Hydrilla verticillata and Vallisneria natans) on rural pond, and the nitrogen and phosphorus removal function of the plants in water, which was experimentized in pilot sink.The results showed that the plants can significantly decrease the concentration of total nitrogen, ammonium nitrogen, nitrate nitrogen, phosphate with a removing rates reached 50.5%, 84.4%, 41.9%, 64.6%, respectively. The density of H. verticillata and V. natans setting to be 20 g/m², and 40 g/m² would be the best options. As water flew through the series unit, there was obviously difference in nitrogen and phosphorus removal efficiency.The removal rates on total nitrogen, nitrate nitrogen, phosphate in planting area were higher than the ones in open area, while to the removal rate on ammonium nitrogen, is higher in open area. Combining dissolved oxygen of the units and the total number of nitrification and denitrification bacteria, it showed that plant units may have significant denitrification, while open units have significant nitrification. Tandeming the open unit and planting unit together could have a better total nitrogen removal effect.