Research On Phosphorus Migration And Transformation In Potamogeton Crispus Rhizosphere Environment

The submerged plants as main plant populations in rivers or lakes are of greatsignificance to regulated phosphorus in overlying water and sediment from riversor lakes. The law of phosphorus migration and transformation in the submergedplant rhizosphere will be explored in this project. It’s purposed to provide a basisfor the practical application of submerged plant to control and repair theeutrophication of rivers or lakes.In this study, Potamogeton Crispus would be selected for the research object.Through the indoor stmulation of Potamogeton Crispus growth in the static riversor lakes cross section, the different forms of phosphorus within the overlying waterand sediment were initially monitored. Then, phosphorus distribution and variationcharacteristics were analyzed, and the relationship between different phosphoruswas speculated. Next, the number of phosphorus bacteria in the sediments fromPotamogeton Crispus rhizosphere was explored. Finally, phosphorus adsorptioncharacteristics of the the sediments were studied. Based on this, the switchingdirection and potential of phosphorus exchange in the water-sediment interfacewere discussed, and phosphorus flux based on an experimental basis wasestimated.The main results are as follows:(1) In the Potamogeton Crispus rhizosphere, TP, DTP and SRP in theoverlying water were efficiently reduced, SUP and PP weren’t. SRP wasthoroughly consumed in three reduction phosphorus forms. SRP as the principalform in the initial time was gradually replaced by SUP.(2) Potamogeton Crispus had no effect obviously on TP, IP, OP, NaOH-P andHCl-P in the sediment.(3) The phosphorus loss in the overlying water depended on SRP; SRP wasmigrated from the overlying water to the sediment and transformed into NaOH-P;then NaOH-P could be into OP in the seiment. The addtion of SUP in the overlyingwater was caused by OP of the sediment. The above process of conversion betweenthe various forms of phosphorus could be strengthened in the Potamogeton Crispusrhizosphere. Total phosphorus of Potamogeton Crispus was24.688g. Phosphorusof Potamogeton Crispus from the overlying water was1.202mg, and phosphorus ofPotamogeton Crispus from the sediment was23.486mg. The contribution ratio was4.87%and95.13%respectively. The source of phosphorus of PotamogetonCrispus was mainly sediments.(4) The process of sediment adsoring phosphorus could be described accurately by the pseudo-second-order kinetic equation. Adsorption in0~0.5h wasfast and in0.5~24h was slow. Modified Langmuir Isotherm Model coulde be welldescribed the adsorption behavior. value assessment method based on theModified Langmuir Model was a better assess to determine phosphorus exchangedirection and potential in the water-sediment interface. Phosphorus was adsored bythe sediment Potamogeton Crispus rhizosphere in the primary time, but wasreleased from the middle time to the end. Phosphorus flux could be declined underthe condition of the Potamogeton Crispus growth.