Effects Of Different Aquatic Plants On Silting And Phosphorus Sedimentary Characteristics In Shifosi Constructed Wetland

The restoration of aquatic plants is an important measure for the ecological restoration of eutrophic lakes.Studying the role of aquatic plants in eutrophic waters is of great significance for the treatment of eutrophication of constructed wetlands and lakes.In this paper,several representative aquatic plants in Shifosi constructed wetland were studied,and the effects of siltation and phosphorus deposition on aquatic plants were studied.Field investigations and laboratory experiments were conducted to analyze and discuss different aquatic plants in sediments.The effects of phosphorus content and depth change,while comparing the biomass differences of aquatic plants in different sediments,studied the effects of nutrients in the sediment on the growth of aquatic plants.Through research,the main conclusions are as follows:(1)Studying the different aquatic plants in the sediment by collecting and comparing the sediments of four different aquatic plants(mixture of lotus,bulrush,reed,submerged,and floating plants)and main rivers in the constructed wetland of Shifo Temple The influence of TOC content and sedimentation depth.The results indicate that the siltation-promoting effect of aquatic plants can cause the sludge to become loose,thereby increasing the depth of the sludge.Due to the cultivation of aquatic plants,the depth of sediment in the wetland increased by about 0.261 m.Overall,the lotus area has the strongest silt-promoting effect,which can bring a sedimentation depth of 0.101 m,the reed area is 0.067 m,the pupa area is0.063 m,and the mixed plant area is 0.030 m.At the same time,the aquatic plants reduce the flow rate and inhibit the suspended matter.Suspension and other effects will produce some non-biofouling.The residues of aquatic plants in the wetland should be harvested and utilized in time to reduce the biodeposition burden of the entire wetland.(2)The sediments and biological plants in the two different aquatic plants of Phragmites australis and P.humilis were collected and compared in the artificial wetland of Shifosi Reservoir.,and the effects of sediments with different nutrient characteristics on aquatic plant biomass were compared..The results showed that the nutrient characteristics of the sediments had a certain correlation with the biomass of aquatic plants in each period.In the early growth stage,the biomass of the reeds and the grasses was negatively correlated with the nitrogen and phosphorus in the sediments.The correlation with TP content reached a significant level(p < 0.05),that is,the higher nutrient content in the sludge inhibited the growth of aquatic plants.With the further growth of aquatic plants,this inhibition gradually became more Small,and gradually transformed into a promoting effect,the correlation between nutrient content and aquatic plant biomass in the sediment changed from negative correlation to positive correlation.After the aquatic plants entered maturity,,the biomass of reed and raupo reached the maximum,and the contents of TN and TP in the sediments were significantly positively correlated with the biomass of aquatic plants.;this relationship gradually disappears as the aquatic plants die.The nutrient level of silt affects the growth of aquatic plants,mainly in the accumulation of biomass.The growth of different aquatic plants is affected differently,and the biomass of the grass is more correlated with the nutrient content in the sediment.(3)Collecting and depositing sediments in four different aquatic plants(mixtures and blanks of lotus,bulrush,reed,submerged,and floating-leaf plants)and blank areas in the artificial wetland of Shifo Temple to study the phosphorus deposition in different aquatic plants.The impact of features.The results showed that aquatic plants could effectively inhibit the release of phosphorus from sediments,and the phosphorus deposition characteristics of different plant regions were different.Among them,the phosphorus content in the sediments of the reeds was the highest,and the phosphorus release ability in the sediments was strong.The content of phosphorus in the sediment in the Pucao area was the lowest,and the release of phosphorus in the sediment was weak,while the blank area without plants had no significant effect on the deposition characteristics of phosphorus in the sediment.When winter aquatic plants begin to rot and decompose,the phosphorus content in the sediments in areas where aquatic plants are grown will increase significantly.