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Floating cyanobacteria in Taihu Lake and Its Mechanism

Author: WuKai
Tutor: LiZhengKui
School: Nanjing University
Course: Environmental Engineering
Keywords: Floating Cyanobacteria Carbohydrates Blooms Taihu Simulation
CLC: X524
Type: Master's thesis
Year: 2011
Downloads: 301
Quote: 2
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Abstract

In recent years, outbreaks of algal blooms in Taihu been widespread concern, the environmental community outbreak mechanism has also become a hot research. Floating algal blooms which is a critical stage of the outbreak, if the float mechanism clearly, you can effectively control the outbreak of algal blooms, thus easing the water crisis. Therefore, the study of cyanobacteria Microcystis particular floating buoyancy regulation and vertical migration feature to reveal cyanobacteria bloom formation mechanism, to understand the mechanism induced algal blooms has very important significance. In this thesis, the National Key Basic Research and Development Program (973 Program), \: 2008CB418003) funded by in situ monitoring and the method of combining laboratory experiments to study the temperature, pH, and other factors on the characteristics of pollutant formation of surface waters China investigated physical and chemical factors driving algal blooms floating in the water column combined effect of the floating algal blooms law; discusses algal blooms floating the main driving factor, trying to reveal cyanobacteria bloom formation and transport law. Mainly studied in situ monitoring of the physical and chemical factors and the Taihu Lake algae blooms floating status characteristics and features indoor simulated using cylindrical pilot reactor simulation cyanobacteria floating process, discusses the physical and chemical factors and regulation of cyanobacteria floating interaction in order to reveal and medium-sized shallow lake Taihu cyanobacteria bloom biology and ecology, and integrated mechanism for the outbreak of algal blooms in the scientific basis of the forecast and early warning, as well as the establishment of cyanobacterial blooms principle of eco-technology integrated control system, proposed cyanobacteria prevention and control of water China The strategy for the realization of ecological safety of water to provide a solid scientific basis for the strategy. The main conclusions of this paper are as follows: (a) dominant species in Taihu Lake, China dominated by cyanobacteria, dominant species of Microcystis (microcystis), algal bloom season biomass was 1.35 × 108 个 · L-1, in addition there is water green algae, diatoms and algae hidden, cyanobacteria and green algae competitive relationship exists between; (2) Spring Lake Taihu nitrate, ammonia, total nitrogen reached the maximum, and total phosphorus, orthophosphate salt and phosphorus ratio changed insignificantly, RDA analysis found that total nitrogen on the growth of cyanobacteria is greater than total phosphorus, total nitrogen and total phosphorus cyanobacterial biomass, DIN / SRP and nitrite has significant correlation should control both nitrogen and phosphorus, especially soluble reactive phosphorus inorganic nitrogen DIN and SRP, as algal blooms control provides a scientific basis; (3) in-situ chemical factors cyanobacteria floating rate and no significant correlation analysis of the reasons may cyanobacteria in situ habitat is more complex, more influential factors, in addition to chemical factors relations, hydraulic conditions may also be affected by other effects; (4) reactor surface algae floating rate was significantly greater than at the bottom, below the surface floating rate no significant variation with time, at different times floating rate variation is r22: 00 gt; r10: 00 gt; r14: 00; (5) pH and orthophosphate variation is greater than the value of the surface and the bottom middle of cyanobacteria in situ for orthophosphate showed strong absorption capacity; (6) carbohydrates, ammonia, DO is the impact of floating algae reactor main physical and chemical factors, cyanobacteria may be mainly through changes in intracellular content of ballast and by synthesizing pseudo- vacuoles to adjust its float.

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CLC: > Environmental science, safety science > Environmental pollution and its prevention > Water pollution and its control > Lakes and reservoirs
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