Study On The Purification Of Eutrophication Water System By Combination Of Physical Materials And Submerged Plants

Eutrophication is one of the major water environmental problems the world facing. The mechanism and remediation techniques research has been the research hotspots at home and abroad. Research shows that when external pollution sources have been effectively controlled, the water body may still have a "secondary pollution" by deposition of pollutants in sediment. Therefore, the internal pollution sources should be eliminated through effective way while external pollution sources were controlled, to create favorable conditions for subsequent ecological restoration and reconstruction. As two important methods of internal pollution sources control and water ecosystem restoration, sediment capping technology and phyto-remediation have caused both academic circle's attention for its low energy consumption and good effect.In this study, physical materials and submerged plants were used to control sediment nutrient release and purify eutrophication water. This paper aims at providing theoretical basis for remediation, to explore a practical, efficient treatment measures. The results showed that:Vallisneria longipedunculata, Hydrilla verticillata, Potamgeton malaianus and Vallisneria spiralis all had a certain TN, TP purification effect, and there were significant differences between each other; the growth conditions and purifying effects on water quality of four submerged plants were:Vallisneria longipedunculata> Vallisneria spiralis> Potamgeton malaianus>Hydrilla verticillata.Single coverage of physical materials and submerged plants can not achieve the desired treatment effect. Physical material capping can inhibit the release of sediment nutrient in the short term, but long-term results are not satisfactory; Although submerged plant can purify eutrophic water significantly, its effect was limited by its own growth conditions and other factors. When Vallisneria longipedunculata and hard physical material coverage ratio is 2:3, the overall purification was relatively better.The submerged plant growth and changes in nutrient concentrations in the overlying water were influenced by temperature, pH, DO values and other environmental factors. While some water nutrient concentrations were correlated between each other. This internal mechanism requires further study.