Study On Water Purification Effect Of Aquatic Plants On Fuhe River In Baoding

With the continuous development of society and economy and the imperfect control measures for water pollution,the phenomenon of water pollution in urban rivers continues to occur.Eutrophication occurs in water bodies leads to algae growth and water pollution,due to nitrogen and phosphorus and other nutrients into the water.Fuhe River is one of the important inland rivers in Baoding City.The water flow rate is relatively slow,there is no steady water supply,and it's supplemented by unconventional water resources such as rainwater and sewage treatment plant effluent.The survey showed that the content of nutrients such as nitrogen and phosphorus in the Fu River water body is rich,and it is in an eutrophic state all year round.Therefore,it is necessary to study the restoration of eutrophic water in Fuhe River and it is also an important way to ensure the quality of the downstream water environment.Firstly,the aquatic plants that can normally grow in the local area are screened through preliminary experiments.Then,the best planting density of the plants is found through static tests,and the plants with the best repair effect on eutrophic water bodies are selected.10 test devices with effective capacity of 90 L are placed side by side on the test site,and three kinds of aquatic plants Hansan grass,Water Hibiscus and Canna are planted according to different planting densities(1/3,2/3,and 3/3 of the total surface area).At the same time,blank plants without plants were used as controls.Water samples were taken at intervals of 24 h from the time the plants were placed and the COD,total nitrogen,ammonia nitrogen,total phosphorus and turbidity,pH,and dissolved oxygen were measured.The results showed that Hansan grass at the removal rate of ammonia nitrogen and total nitrogen average reached 78.74% and 48.79% at 1/3 planting density,and Water Hibiscus at the net removal rate of COD and total phosphorus average was 58.72% and 79.38% at 1/3 planting density.In order to increase the effect of phytoremediation of eutrophic water bodies,the related effects of reoxygenation on phytoremediation of eutrophic water were studied.T Place 12 test devices with an effective volume of 90 L in the test site,and place a small aeration pump in the device for aeration and reoxygenation.Combine the screened plants and artificial reoxygenation with no plants.The blank device is the control group.The selected plants are combined with artificial reoxygenation in the optimal planting area.A plastic bucket without plants is used as a control group.Water samples were taken at intervals of 24 h from the time the plants were placed.Chemical indicators such as COD,total nitrogen,ammonia nitrogen,total phosphorus and turbidity,pH,and dissolved oxygen were measured.The results showed that the average removal rate of ammonia nitrogen was 86.41% in A.Hansan grass-artificial reoxygenation,and Water Hibiscus-artificial reoxygenation,the average removal rates of COD,total nitrogen and total phosphorus were 80.28%,62.07% and 92.24%.Study on the practical application effects of plants in eutrophic waters by Simulating the flow of rivers in the test room.On the basis of static tests,HanSan grass,Water Hibiscus were selected and planted at a density of 40% according to a 1:1 mixture.Seven plastic buckets with an effective volume of 90 L were used as test devices in series.The test plants were planted from the second plastic barrel,and representative points were selected as sampling points.The flow rate of the device was adjusted to 0.01m/s.Water samples were taken at intervals of 24 h from the time the plants were placed.Chemical indicators such as COD,total nitrogen,ammonia nitrogen,total phosphorus and turbidity,pH,and dissolved oxygen were measured.The plants with growing evenly were selected before and after the experiment.And measure the total nitrogen and total phosphorus contents of the plants above and below ground.The results showed that the removal rates of COD,ammonia nitrogen,total nitrogen,nitrate nitrogen and total phosphorus reached 68.50%,83.93%,83.85%,89.49% and 76.76% respectively.The content of nutrients in the plant after the end of the experiment was before the test.1.3 to 2.5 times.The results show that aquatic plants can effectively remove nutrients in eutrophic water and have a positive effect on water restoration.The removal effect of nitrogen on HanSan grass was better,and Water Hibiscus had a better removal effect on phosphorus,which all could achieve the effect of restoring eutrophic water.