The Study Of The Potential Of Filamentous Algae On The Eutrophicated Water Remediation

The phenomenon of water eutrophication has become a global environmentalproblem and the primal problem of natural water in our country like ponds, lakes andrivers is Blue-green algal. For eutrophication problems, both at home and abroad,have developed many related researches, but the problems are still not solved. Thisthesis uses two large filamentous algae of Spirogyra and Cladophora glomerata toinvestigate the restoration experiment of eutrophication water. From both theinfluence of algae community and the effect of water quality, the paper discussed therepair potential of the two filamentous algae for eutrophication water at the algaerecovery stage, and compared the differences of Spirogyra and Cladophora glomeratain water eutrophication repair process.To study the effect of filamentous algae on the recruitment of cyanobacteria（mainly Microcystis） in eutrophic water body, a simulative experimental appliancewas designed. Meanwhile the effect of nutrients was also investigated in the presentstudy. Intact surface sediments from an open pool of eutrophic water were put into theappliance bottom and the water was gently added on preset surface sediments. Threelevels of filamentous algae biomass (high42mg·L^-1, low21mg·L^-1, control0mg·L^-1) were adopted and the experiment was carried out under natural light fromMarch to May2010. The results stated clearly that Spirogyra could prominentlyaltered the water environment. Shading rate could reach93%at a high dose ofSpirogyra, and even84%at a low dose. Spirogyra could lower the temperature ofsediment surface and greatly absorb nitrogen and phosphorus nutrients of the water.The shading effects of Spirogyra on the water environment might be the main reasonthat Spirogyra inhibited the recruitment of cyanobacteria and changed the algalcommunity structure. Even with abundant nutrition, the effect of Spirogyra oncyanobacteria recruitment was still significant. The shading effects of Spirogyraplayed a key role in inhibited the recruitment of cyanobacteria and changed the algalcommunity structure.The Cladophora glomerata can effectively remove the nitrogen and phosphoruspollutant and reduce the turbidity of water. The inhibitory action to blue-green algaefrom Cladophora glomerata derived from the competition of nutrient, and enoughnutrient could influence the inhibiting effect of Cladophora glomerata to blue-greenalgae.