Effect Of Algae Population Structure And N、P By Ecological Floating Bed

Nowadays, eutrophication in China is very hard, not only undermined the ecological environment of the water system, but also a direct impact on the water source of water supply, so the problem of repairing lakes has become environmental hot spots. Artificial floating bed is a water body restoration, have the advantages of efficient, economical, no secondary pollution, and so on. But the effect is produced by plants, so the ecological floating bed combined by animal and plants has an important value.The study is to improve the water quality of Chaohu water source by ecological floating bed as the research objectives, using a combination of simulation and lake monitoring test to study the effects by plant unit, animal unit, and flora and fauna coupling effects on the body of water algae population structure, adsorption, blocking role effects, water purification, further study the impact of Microcystis aeruginosa which is the advantage algae in Chaohu by plant extracts. The main conclusions are as follows:(1)In the outdoor simulation, Eichhornia crassipe、Alternanthera philoxeroides、Hypophthalmichthys molitrix are to reduce the total biomass of algae in water, the Eichhornia crassipe+Hypophthalmichthys is best, though Hypophthalmichthys molitrix only can reduce algae biomass, but the total number is increase,by the end of the experiment, the inhibition efficiency of each treatment is79.9%.78.9%.4.6%.83.2%.79.3%; the inhibitory effects of blue、green algae is different between the each treatment, Hypophthalmichthys molitrix can effectively inhibit Bacillariophyta and Euglenophyta with big bodies. But have the poor results on blue、green algae. The floating bed can adsorp and interceptor the algae to bed line region, which has greater biomass than the control region.So the eological floating bed can reduce the aggregation of cyanobacteria in the core area of the water intake. (2)In the indoor simulation experiment, three kinds of plants can inhibit the growth of Microcystis aeruginosa in the symbiotic condition, which Pistia stratiotes is the best, followed by Eichhornia crassipe, the worst is Alternanthera philoxeroides. when the plants are planted6.3g/L, the inhibitory rate of Microcystis aeruginosa is reaching90.1%、86.8%、75.7%. Growing liquid of Three kinds of plants culture Microcystis aeruginosa and found that low concentrations of Pistia stratiotes can promote the growth of Microcystis aeruginosa, but high concentrations have the inhibit effaces, medium of Eichhornia crassipe and Alternanthera philoxeroides have the same inhibitory effects. Inhibition rate is Eichhornia crassipe> Alternanthera philoxeroides> Pistia stratiotes.(3)Results of plant extracts cultureing Microcystin aeruginosa test show that The three plant extracts inhibited the growth of Microcystis aeruginosa, inside Alternanthera philoxeroides is best,12d of the expriment, Microcystis aeruginosa were all dead, Pistia stratiotes stem have good inhibitory effect, which have48.35%inhibitory rate under the same conditions, the higher of the concentration of extracts and the higher of inhibition of the effect of Microcystin aeruginosa, when add4%of the root and stem extracts of plants, Microcystin aeruginosa were all died at12d.(4) Eichhornia crassipe and Alternanthera philoxeroides can effectively ab-sorb TN、TP in the water, and Eichhornia crassipe is better than Alternanthera philoxeroides; the inhibitory effects of Eichhornia crassipe is better than Alternan-thera philoxeroides,the nitrate removal rate was78.9%,75.0%,73.7%,67.1%,11.8%by Alternanthera philoxeroides+Hypophthalmichthys、Alternanthera philoxeroides、 Eichhornia crassipe+Hypophthalmichthys、Eichhornia crassipe Hypophthalmichthys, which plants+Hypophthalmichthys> plant> Hypophthal-michthys. At the Purifying effect on nitrate, Eichhornia crassipe+Hypophthalmich-thys> Alternanthera philoxeroides+Hypophthalmichthys> Eichhornia> Alter-nanthera philoxeroides> Hypophthalmichthys, among all the treatments, the nitrate removal rate of Eichhornia crassipe+Hypophthalmichthys up to53.6%, but Hy-pophthalmichthys just12.4%.In summary, ecological floating bed can effectively inhibit the growth of algae, affecting algae population structure, improve the water quality of water sources and landscaping.