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2017 IWA Symposium of Lake and Reservoir Management
Shanghai, China, 22-26 May, 2017
Environmental Influence and Growth Characteristics of Cyanobacteria in
Qingcaosha Reservoir
Xianyun Wang*
(Shanghai Engineering Research Center of Urban Water Resources Shanghai National Engineering Research Center of Urban
Water Resources Co.，Ltd.Shanghai, China)
Presenting Author: Xianyun Wang
Keywords: Qingcaosha Reservoir; Cyanobacteria; Growth variation; Nutrients limiting factor
Introduction
Environmental influence and growth characteristics of Cyanobacteria in Qingcaosha reservoir were studied and analyzed.
The results revealed the growth characteristics of Cyanobacteria and influence mechanism to Cyanobacteria in Qingcaosha
reservoir , especially the nitrogen and phosphorus nutrient use ,which provided the basis for cyanobacteria outbreak control.
Materials and Methods
1. Sampling sites
Fig.1 Sampling sites diagram in Qingcaosha reservoir
2．Logistic model
Microbial growth was in accordance with the following formula
- dA =kA
dt
,In the formula,A —algae cell density;k—growth rate
Amax was potential limit value of algal cells,and the growth rate formula was below
- dA =k- k A
Amax
, Adt
,then through Differential Equation, Finally could get SLogistic model for the growth of algal
A=
cells:
Amax
1+ea-kt
,In the formula,a —undetermined parameter.
3. The cell growth rate formula
Monod formula
half-saturation constant.
, In the formula, μm is maximum growth rate, C is limit nutrient concentration, Kμ is
4. Analysis software
SPSS 19.0 Origin8.0 Canoco5.0 SPLUS8.0
Results and Discussion
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2017 IWA Symposium of Lake and Reservoir Management
Shanghai, China, 22-26 May, 2017
Fig.2 Correlation analysis between algae density and wind speed
Fig.3 Correlation analysis between blue-green algae density and velocity
Fig.4 Correlation analysis between algae and blue-green algae density and water temperature
Fig.5 The influence of water temperature on different algal growth competition in Qingcaosha reservoir
Conclusions
1.The wind speed of high algae biomass (> 20 μg/L) is mainly 2 ~ 3 m/s
2.The Cyanobacteria density decreased with the velocity index In the form of index and the fitting curve equation is y =
3.03153E21*exp(-x/ 1.95212E-4) + 8.61951E6*exp(-x/ 0.01192) +1.22271E6，R2=0.2284.
3. 25 ℃ is the optimal and peak temperature of algae growth; 15.2 ℃ is competition turning point between diatoms and
blue-green algae ; 20.3 ℃ is stagnation temperature of Planktothrix increasing rapidly.
4.N is the main limiting factor of the growth of algae and blue-green algae, especially NO3N.
References
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rates[J]. 1990,12(6):1117-1151.
[2]Laws E A. Evaluation of in situ phytoplankton growth rates: a synthesis of data from varied approaches[J].
2013,5:247-268.
[3]Moreira Santos M, Soares A M, Ribeiro R. A phytoplankton growth assay for routine in situ environmental
assessments[J]. 2004,23(6):1549-1560.
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