Mechanism of the influence of hydrodynamics on Microcystis aeruginosa, a dominant bloom species in reservoirs
Mechanism of the influence of hydrodynamics on Microcystis aeruginosa, a dominant bloom species in reservoirs
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水动力对水库水华优势种铜绿微囊藻的影响机制
DOI：
10.1016/j.scitotenv.2018.04.257
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发表时间：
2018
影响因子：
9.8
通讯作者：
Zhang Yao-Wen
中科院分区：
文献类型：
--
作者：
Song Yang;Zhang Ling-Lei;Li Jia;Chen Min;Zhang Yao-Wen
水动力条件对水华的发生起着重要的作用，水华对水环境尤其是水库的威胁日益严重，而微囊藻（Microcystisaerodiosais）是水库水华的优势种，在水华发生时会释放大量的藻毒素。利用定制的水力旋转装置，探讨了藻类生长特性及水动力条件影响的相应机理。长期实验结果表明：（1）相对于静水，中等流速能提高藻类生长速率，延长藻类寿命;（2）中等水流扰动能促进藻类细胞的能量代谢和营养吸收;（3）中等切应力能降低藻类细胞的氧化水平，改善藻类细胞形态;（4）扫描电镜（SEM）显示，在水力作用下，藻细胞发生了变形，由0.5m/s的水流引起的0.0104Pa的高剪切应力可能破坏了藻细胞的形态，干扰了活性氧（ROS）的代谢;（5）藻细胞形态学评价（包括圆率、偏心率、直径增长率和变形率）;（6）根据藻类生长状况和具体影响，（包括“正促进”、“中促进”、“负促进”、“过渡”和“抑制”）和流体动力学阈值系统（包括流速，湍流耗散，和剪切应力）建立;和（7）为M。铜绿假单胞菌的最佳流速为0.24 m/s，静态等效流速为0.47 m/s。这些结果为水动力对藻类生长的影响提供了一个基本的总结，也为M.水库中的高空气球
Hydrodynamic conditions play a key role in algal blooms, which have become an increasing threat to aquatic environments, especially reservoirs.Microcystisaeruginosais a dominant species in algal blooms in reservoirs and releases large amounts of algal toxins during algal bloom events. The algal growth characteristics and the corresponding mechanism of the influence of hydrodynamic conditions were explored using custom hydraulic rotating devices. The long-term experimental results were as follows: (1) a moderate flow velocity increased the algal growth rate and prolonged algal lifetime relative to static water; (2) moderate water turbulence promoted energy metabolism and nutrient absorbance in algal cells; (3) moderate shear stress reduced oxidation levels in algal cells and improved algal cell morphology; (4) under hydrodynamic treatment, algal cell deformation was confirmed by scanning electron microscopy (SEM), and a high shear stress of 0.0104 Pa induced by a flow of 0.5 m/s may have destroyed cell morphology and disturbed reactive oxygen species (ROS) metabolism; (5) algal cell morphology evaluation (including circle ratio, eccentricity, diameter increasing rate, and deformation rate) was established; (6) based on algal growth status and specific effects, five independent intervals (including ‘positive-promotion’, ‘middle-promotion’, ‘negative-promotion’, ‘transition’, and ‘inhibition’) and the hydrodynamic threshold system (including flow velocity, turbulent dissipation, and shear stress) were established; and (7) forM. aeruginosa, the optimum flow velocity was 0.24 m/s, and the static-equivalent flow velocity was 0.47 m/s. These results provide a basic summary of the hydrodynamic effects on algal growth and a useful reference for the control ofM. aeruginosablooms in reservoirs.