The Research On Purification Of 5 Species Aquatic Plants In Eutrophic Water

As the economy grows, people’s living standards improve, environmental problems followed.The problem of eutrophication of water body in city park is becoming more serious, water governance is increasingly a matter of concern. Now, aquatic plant as the core of the wastewater treatment and eutrophication water body restoration are great ways to landscape water management. Aquatic plant is one of the indispensable elements to create the water landscape. It’s not only beautify the environment,but also it can adsorb or remove pollutants in water, so as to achieve the effect of purifying water. Paper uses sample method to investigate and analysis the eutrophication status of water body and the application situation of aquatic plant in 9 city parks in Changsha. Then 5 species are selected out as the try plant, and planted in self-made eutrophic water in groups.Next, paper uses phosphorus molybdenum blue Spectrophotometric method and alkaline potassium persulfate digestion-UV spectrophotometry method, potassium bichromate method for determination, Nessler’s reagent colorimetric determination of eutrophication to gauge relevant index in water regularly, and obtains the purification ability of the try plant through data processing and analysis. According to the different purification ability, combined with the theory about aquatic plant and methods, Presented in plan configuration modet about eutrophication water in changsha, In order to provide a reference for landscape design of eutrophication water in changsha park. Results were as follows:(1)According to the selection in Park waters obtained the nutrition level 4, That are serious eutrophication, respectively to eutrophication, eutrophication, medium-eutrophication. Among them, The martyrs’Park water status is serious eutrophication, The Moon Lake Park is eutrophication of the water, The Xiaoyuan Park is middle eutrophication, The South Park and West Lake Park water are eutrophication. And then through the survey found aquatic plant species there are 54,44 genera belonging to 24 families, mostly for macrophytes, floating leaf and floating plants, submerged plants appear less. Suit focuses on purple, white, yellow, pink or red. Such as Thalia dealbata, Iris Wilsonii and so on. Plant height is centered largely in the 100-200cm,30-60cm etc, and appropriate depth for 40-50cm.(2)According to the frequency analysis and principles of aquatic plants in landscape analysis as well as remediation, Filter out high frequencies and excellent ornamental effect of 5 types of aquatic plants:Hydrilla verticillata, Pistia stratiotes, Thalia dealbata, Typha orientalis, Iris Wilsonii as tested plants, with single and combination treatment is divided into 7 groups (including a control group).(3) The 7 treatment groups plants were planted in the self-distribution eutrophic water sample. The results were analysed by observeing and testing for 60d. The results showed that the 7 treatment groups plants had different purification effects to the TP, TN, CODcr and ammonia nitrogen of the selected water bodies. The pH value of the selected water bodies were 6.5 to 8.5, The removal rate of TP was Combination>Thalia dealbata> Pistia stratiotes>Hydrilla verticillata>Iris wilsonii>Typha orientalis>Blank. Combination of TP removal rate as high as 97%; The removal rateof TN was Thalia dealbata> combination> Pistia stratiotes> Typha orientalis> Hydrilla verticillata> Iris Wilsonii> blank, Thalia dealbata of TN removal rate ashigh as 94.75%; The removal rate of CODcr was Iris Wilsonii> Thalia dealbata> combination> Pistia stratiotes> Typha orientalis> Hydrilla verticillata> blank, Iris Wilsonii of CODcr removal rate as high as 97.5%; The removal rate of NH3-N was Thalia dealbata> Hydrilla verticillata> combination> Iris Wilsonii> Typha orientalis> Pistia stratiotes> blank, Thalia dealbata of NH3-N removal rate as high as 99.34%; The improved effects of DO levels were Hydrilla verticillata> combination> Iris Wilsonii> Thalia dealbata> Pistia stratiotes> Typha orientalis> blank.(4)By summarizing the previous studies on the plants with better purification water and inducing common species of aquatic plants in eutrophic water. Based on these results and eutrophication plant basic principles, to analysis the selection of park landscape water case optimize allocation.For example, Martyrs park available configuration for’.Typha orientalis+Arundo donax+Pontederia cordata+Nymphoides peltatum-Nelumbo nucifera+Potamogeton distinct; Gui Hua park available configuration for.Canna indica+Polygonum hydropiper+Acorus tatarinowii; Province Botanical Garden configuration for:Thalia dealbata+Iris Wilsonii+Pistia stratiotes+Hydrilla verticillata; Moon Lake Park configuration for.Scirpus validus+Calla palustris+Ceratophyllum demersum, Thalia dealbata+Iris Wilsonii+Euryale ferox+Elodea nuttallii.