Study Of Purification Effects Of The Aquatic Animals And Plants And Their Combination System On Eutrophic Scenic Waters

The population time of Waterscape is coming but the tedious maintenance jobs like getting rid of the algae,dust and insects,together with the high cost and technology problems for the maintenance of the water quality,result in many waterscape exhausting and drying out.At present,the waterscape mainly focuses on aquatic herbs which is apparently good to the waterscape construction because aquatic herbs do not need the demanding maintenance.Based on this,this essay studies the experiment that focuses on the aquatic woody plants and matches with the aquatic herbs both of which are suitable for growth,the aquatic animals,as well as the high-absorbability Biomass Char for pollution adsorption and plant support and builds a natural Ecological Integrated Purification System,thus provides theory reference and technical support for the waterscape purification,the design of waterscape and the recovery of the polluted water ecological system.And the main results are listed as below:1.11 species of woody plant have a role in purification effect for eutrophic waterscape.The experimental materials are Cleistocalyx operculatus,Bischofia javanica,Ilex rotunda,Barringtonia racemosa,Callistemon viminalis,Elaeocarpus hainanensis,Elaeocarpus apiculatus,Sapium sebiferum,Melaleuca bracteat,Metasequoia glyptostroboides and Cephalanthus tetrandrus.The result shows that the Bischofia Javanica has the best purification effect for the TN,TP and NH4+-N of the polluted water with the removal rate as52.2%,28.8% and 36.3% and Callistemon Viminalis' s purification effect for the TN and TP ranks only second to Bischofia Javanica with the removal rate as 51.9% and 25.6%.And the absorbing effect of the Cephalanthus Tetrandrus for the COD is good with the removal rate as 28.7% and 32.6%.Therefore,Bischofia javanica,Callistemon viminalis and Cephalanthus tetrandrus can be the priority choices for the water purification with the Elaeocarpus hainanensis,Barringtonia racemosa,Elaeocarpus apiculatus,Ilex rotunda,Melaleuca bracteata,Sapium sebiferum,Metasequoia glyptostroboides and Cleistocalyx operculatus ranking the second place.2.Eight kinds of aquatic herbs have the purification effect for eutrophic waterscape but the purification efficiency of them are different greatly.The materials of the purification experiment are the common aquatic herbs: Hymenocallis littorali,Scirpus triqueter,Pontederia cordata,Iris germanica,Hydrocotyle vulgaris,Hygrophila salicifolia,Vallisneria natans and Hydrilla verticillata.During the 10-day experiment,by control experiment,Hygrophila salicifolia enjoys a good purification effect for the TN,TP,COD,NH4+-N and Chroma with the removal rate as 50.3%,25.4%,38.5%,23.5% and 27.9%.And for the purification for the TN,Iris germanica,Hymenocallis littorali and Vallisneria natans rank the second place with the removal rate as 44%,39.1% and 37.4%.Scirpus triqueter getting rid of the TP ranks only second to Hygrophila salicifolia with the removal rate as 20.6%.Comprehensively,Hygrophila salicifolia can be the priority of the aquatic herbs for the water purification,and the Iris germanica,Hymenocallis littoralis and Vallisneria vatans ranks secondly.3.The four kind of the aquatic animals have different survival rate in the eutrophic water and has a significant influence on the water quality.Hypophthalmichthys molitrix and Gambusia affinis all died at the end of the experiment and for the group of Macropodus opercularis and Cipangopaludina cahayensis,there wasn't death found.With the death of Hypophthalmichthys molitrix and Gambusia affinis,the concentration of the TN,TP and NH4+-N grew rapidly and of which,TN and NH4+-N grew most with the concentration of them higher 16.37~18.35mg/L and 17.19~19.65mg/L than the initial values.Macropodus Opercularis has strong adaptability to polluted water because it cannot only eat the larvae and mosquitoes,but also reduced the TP,COD,NH4+-N and Chroma with the removal rate as 15.5%,37%,40.8% and 19.1%.And the Cipangopaludina cahayensis can help to lower the pH value and Chroma and has a good purification effect for the COD of the polluted water with the removal rate as 36.5%,which reach the removal rate of Macropodus opercularis.Concludingly,so the Macropodus opercularis and Cipangopaludina cahayensis can be the priority choice for the water purification.4.Assemblage of aquatic animals and plants has a good purification effect for the eutrophic waterscape and the larvae and mosquitoes cannot be found in this system.During the 30-day experiment,the concentration of the TN,TP,COD,NH4+-N,NO2--N and Chroma are reduced to a large extent with the removal rate as 64.4%,49.5%,65.7%,73.8%,82.6% and 68.9%,and of which,TN and COD is up to the Standard of IV Surface Water and NH4+-N reaches the standard of ?water.