Study On The Restoration Effect Of Aquatic Ornamental Plants Combination On Eutrophic Water

Water eutrophication has become a common environmental problem in the world.Water eutrophication will damage the landscape effect,endanger human health,and cause a bad impact on the ecological environment.On the other hand,in recent years,the global warming trend continues,and the rising temperature and the salinization caused by it make water eutrophication more likely to occur,which hinders the restoration of water eutrophication.Among the remediation technologies for eutrophication of water,phytoremediation is currently a research hotspot for eutrophication due to its environmental protection and low cost.Especially,the use of aquatic ornamental plants for the restoration of eutrophic water has not only good purification effect,but also beautify the water environment.In Wuhu in Anhui province Dapu Country World of upstream near the sewage treatment plant area of Puxi lake water eutrophication as the background,selecting optimum was born in six kinds of aquatic plants,the Yangtze river basin of six kinds of aquatic ornamental plants combination,first explores the different combination of aquatic ornamental plants with different concentrations of eutrophication of water body purification effect and the response of the growth and development of,The combination of aquatic ornamental plants with ecological value and landscape value was selected.Secondly,the plant combination with the best purification effect was selected as the research object to explore whether and how its restoration effect on eutrophic water under the background of global warming was affected by high temperature and salinity.It provides some reference basis for the restoration of eutrophic wate,the plant design of ecological waterscape,and the planting and application of aquatic ornamental plants under the trend of global warming.(1)The purification effects of the six aquatic ornamental plants combinations were different in different eutrophication concentrations.In the eutrophic water with low concentration,the combination of Iris pseudacorus + Nymphaea tetragon + Ceratophyllum demersum and the combination of Scirpus validus + Nymphaea tetragon + Ceratophyllum demersum showed good removal effect on total phosphorus(TP),total nitrogen(TN)and chemical oxygen demand(COD),while the combination of Scirpus validus + Nymphoides peltatum + Ceratophyllum demersum can effectively remove TN and ammonia nitrogen(NH3-N).In the later stage of the experiment,the removal effect of TP could be gradually exerted by Lythrum salicaria + Nymphaea tetragon + Ceratophyllum demersum.In the medium concentration eutrophication water,the combination of Iris pseudacorus +Nymphaea tetragon + Ceratophyllum demersum has the best purifying effect on TP,TN and COD,while the combination of Nymphaea tetragon + Ceratophyllum demersum has the best purifying effect on TP,NH3-N and the aeration effect on water.In high concentration eutrophication water,the combination group of Iris pseudacorus + Nymphaea tetragon +Ceratophyllum demersum can effectively remove the nutrients TP,TN,NH3-N and COD,while the combination of Scirpus validus + Nymphaea tetragon + Ceratophyllum demersum has a good purification effect of TP,TN and COD.During the experiment,among the emersion plants,Lythrum salicaria grew the fastest.The growth of the submerged plants combined with Nymphoides peltatum was generally weaker than that of the submerged plants combined with Nymphaea tetragon,and a similar situation existed among the emergant plants in the eutrophic water with low concentration,suggesting that there might be a competitive relationship between plants in the plant assemblages.(2)The effects of high temperature and salinity on the phytoremediation of eutrophic water bodies were studied with the best combination of aquatic ornamental plants: Iris pseudacorus + Nymphaea tetragon + Ceratophyllum demersum The results showed that both high temperature and salinity had certain effects on the growth of aquatic plant combinations and the purification effect of eutrophic water.In the high temperature treatment,the growth status of the three plants in the plant combination is good;The effect of plant combination on the removal of TP is obvious,while the effect on the purification of TN,NH3-N and COD is relatively small.However,in the extreme high temperature,the growth of plants was inhibited by the extreme high temperature stress to some extent,and the purification effect of plant assemblages on nutrients was significantly lower than that of normal temperature group and high temperature group.On the other hand,salinity has a certain inhibition effect on plant growth.The higher the salinity,the more obvious the inhibition effect is.In the high salinity treatment,the purification effect of plant to each nutrient salt was obviously inhibited;In the low salt treatment,the plant combination has a certain purification effect on COD,and the purification effect on TP and NH3-N is better in the middle and late stage.