Study On Purification Effect And Partial Resistance Of Different Flowers And Plants To Eutrophic Water Under Ecological Floating Bed System

Since the reform and opening up,with the rapid development of China's economy,a series of environmental problems have emerged,such as land desertification,acid rain,air pollution,toxic chemicals pollution and so on.The eutrophication of water body in China has existed since ancient times,but the modern human activities aggravate this environmental problem.Eutrophication of water body not only destroys the ecological environment system of water body,but also directly affects the water supply of water source,so it is increasingly urgent to repair the polluted water body.Artificial ecological floating bed technology is a water restoration technology,which has the characteristics of economy,high efficiency and no secondary pollution.In recent years,remarkable achievements have been made in the treatment of reservoirs and lakes.At present,researchers mostly use some common aquatic and terrestrial plants in the local area,and few use flower plants for floating bed experiment,and usually pay more attention to the purification effect of various nutrients in the water body.Therefore,this study starts with the static experiment of floating bed of plants,selects the common and ornamental,practical flower plants in Anhui area to construct the ecological floating bed system,and carries out parallel experiment The plant species with better treatment effect were tested,and the stress resistance under heavy metal stress was further studied to provide certain basis for the selection of test plants in the actual engineering experiment.The main conclusions are as follows:?1?In the two experiments,the growth of each group of plants was good,in which the biomass of Spathiphyllum kochii increased by 78g in the experimental cycle,the growth rate was 15.6%,which was the lowest growth rate among all kinds of plants and combinations.The adaptability of Polygonum lapathifolium was strong,and the growth rate was the highest,191.6%.In the two experiments,the growth rate of Hydrocotyle chinensis was 111.6%and 102.4%respectively.Seven kinds of plants can effectively inhibit the growth of algae in the water.In the two experiments,the inhibition effect of Hydrocotyle chinensis and Polygonum lapathifolium is the best,which can reduce the growth of algae density in the water to a lower level.Seven kinds of plants have good purification effect on ammonia nitrogen and total phosphorus,among them,Epipremnum aureum,Hydrocotyle chinensis and Polygonum lapathifolium have the best purification effect,which can degrade ammonia nitrogen and total phosphorus to a lower level.Although the two groups of blank control also had degradation effect on ammonia nitrogen and total phosphorus,excessive algal eruption not only made the water quality turbid,dissolved oxygen decreased,but also sent out odor,which damaged the aquatic ecosystem.?2?In the case of mixed planting of Epipremnum aureum,Spathiphyllum kochii,Chlorophytum comosum and Hydrocotyle chinensis.The combination of Epipremnum aureum and Spathiphyllum kochii,and Epipremnum aureum and Hydrocotyle chinensis can better inhibit the growth of algae,while the combination of Epipremnum aureum and Chlorophytum comosum can increase the density of algae when they are planted separately.Compared with the mixed planting of the other three plants,the pure effect of Epipremnum aureum and total phosphorus can be slightly improved by the separate planting of the Spathiphyllum kochii and the Chlorophytum comosum,but the combination of Hydrocotyle chinensis a can not obviously see the gain effect.?3?After adding heavy metal copper into the eutrophication water,the results showed that the algae density of the water tank with heavy metal copper was kept at a low level no matter in low concentration or high concentration.Under the stress of1.15mg/L copper,the removal rates of ammonia nitrogen,total phosphorus and Cu²⁺were higher in the same concentration,which were 23.47%,2.72%and 3.01%higher than those of Rohdea japonica?Thunb.?Roth.For the increase of heavy metal concentration,there was no significant change in the purification effect of Hydrocotyle chinensis on ammonia nitrogen,total phosphorus and Cu²⁺,while the purification effect of Rohdea japonica?Thunb.?Roth on copper was significantly reduced.With the increase of heavy metal concentration,The activities of all kinds of enzymes in the body of Hydrocotyle chinensis and Rohdea japonica?Thunb.?Roth all changed in different degrees,but the change trend of the same enzyme activity was the same.The activities of peroxidase?POD?and malondialdehyde?MDA?increased with the increase of copper ion concentration,and the activities of catalase?CAT?decreased with the increase of copper ion concentration.In contrast,Rohdea japonica?Thunb.?Roth had poor tolerance to heavy metal copper...