三种水华藻类在振荡条件下的磷吸收动力学及生长预测研究

COMPARATIVE STUDIES ON PHOSPHORUS UPTAKE KINETICS AND GROWTH PREDICTION OF THREE BLOOM-FORMING ALGAE UNDER TURBULENCE

为了探讨水动力对不同水华发生和演替的影响,以3株常见水华藻类,铜绿微囊藻(蓝藻)、普通小球藻(绿藻)和汉氏冠盘藻(硅藻)为材料,研究了不同流速条件下(0,0.38m/s)3种水华藻类的磷吸收动力学行为,并根据磷吸收动力学参数对3种水华的生长进行预测。结果表明,振荡(0.38m/s)能显著降低铜绿微囊藻(Microcystis aeruginosa)和汉氏冠盘藻(Stephanodiscus hantzschii)的磷吸收速率和亲和力(p<0.05),但显著提高普通小球藻(Chlorella vulga)的磷吸收速率和亲和力(p<0.05)。根据Monod模型预测,水体扰动能不同程度的抑制铜绿微囊藻和汉氏冠盘藻的生长而促进普通小球藻的生长。3种水华藻对扰动条件的不同生理响应可能是导致河流中优势藻规律性分布与演替的原因之一。因此随着河流水体流速的减慢和磷浓度的升高,可能出现硅藻水华向蓝绿藻水华演替的风险。

In order to explore the effect of hydrological regimes on algae bloom and succession,3species from different phylum,Microcystis aeruginosa(Cyanophyta),Chlorella vulga(Chlorophyta)and Stephanodiscus hantzschii(Bacillariophyta),were used in present study to compare the effects of turbulent conditions(0and 3.8m/s)on the phosphorus(P)uptake kinetics in different bloom-forming algae.The growth rates of three algae were predicted under standing and turbulent conditions according to their P uptake kinetic parameters.Our result showed that hydrodynamic can significantly affect the growth of algae by changing the P uptake rates and hydrodynamic impacted different algae differently.Compared to standing condition,the P uptake rates and P affinity of M.aeruginosaand S.hantzschii under turbulence declined markedly(p<0.05),however,the P uptake rates and P affinity of C.vulgaincreased significantly(p<0.05).Based on Monod model,the turbulence could inhibit the growth of M.aeruginosa and S.hantzschii in different degrees but boost the growth of C.vulga.Our results reveal that the difference characteristic of phosphorus uptake kinetics in three bloom-forming algae under turbulent and standing conditions might result in distribution and succession of algae in rivers.With the increase of P concentration and decrease of flowing rate in rivers,the risk of blooms from diatoms to cyanobacteria will be increased.