| 混合胁迫条件下蓝藻运动特性研究 |
| 摘要点击 1573 全文点击 844 投稿时间：2013-09-03 修订日期：2013-10-24 |
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| 中文关键词 蓝藻 曝气混合 运动特性 气囊 密度 |
| 英文关键词 Cyanobacteria water-lifting aeration movement characteristic gas vesicle density |
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| 中文摘要 |
| 为了探究混合控藻技术对蓝藻运动分布特性的影响，实验测定了太湖蓝藻在不同光照度、温度、压力等条件下的上浮/下沉速度. 蓝藻在1500~6000 lx光照度范围内均表现出很强的上浮性能，光照度大于1500 lx时，上浮速度大于0.8cm·min-1的藻颗粒占58%；当光照度小于1500 lx或大于6000 lx时上浮速度将减弱. 在8~25℃ 环境下，蓝藻呈上浮运动，且随着温度的升高，上浮速度增加. 在0~0.1 MPa压强条件下蓝藻上浮，且随着压强的增加上浮速度减慢；当压强达到0.2~0.3 MPa时大部分蓝藻悬浮于水中，只有少部分上浮或下沉；当压强达到0.4~0.6 MPa时，蓝藻明显下沉，且随着压强的增加下沉速度增大，0.6 MPa压强下，下沉速度大于1.0cm·min-1的藻颗粒占52.5%. 当外界压力超过藻细胞气囊所能承受的范围，气囊开始破裂，藻细胞的浮力变小直至小于其重力，导致藻颗粒下沉. 常压下，藻颗粒粒径越大，上浮速度越快，密度越小；高压下，藻颗粒粒径越大，下沉速度越快，密度越大. |
| 英文摘要 |
| In order to study the impact of algae control mixing technology on the distribution characteristics and movement of Cyanobacteria, the floating and subsiding velocity of Cyanobacteria in Taihu Lake was measured under different conditions such as different illuminance, temperature and pressure. The Cyanobacteria showed strong propensity of floating under the illuminance from 1500 lx to 6000 lx. The Cyanobacteria particle with floating velocity of more than 0.8cm·min-1 accounted for 58% under the illuminance of 1500 lx. The floating velocity slowed down when the illuminance was lower than 1500 lx or higher than 6000 lx. In the temperature range of 8 to 25 Celsius degree, the Cyanobacteria floated and the floating velocity increased with temperature. The Cyanobacteria floated under the pressure of 0-0.1 MPa and the floating velocity slowed down as the pressure increased. Most Cyanobacteria were suspended in the water when the pressure reached 0.2-0.3 MPa and only a small part of the Cyanobacteria floated or settled. When the pressure reached 0.4-0.6 MPa, the Cyanobacteria notably settled and the subsiding velocity increased with the increase of pressure. The Cyanobacteria particles with subsiding velocity of more than 1.0cm·min-1 accounted for 52.5% when the pressure was 0.6 MPa. Gas vesicles bursted when the gas vesicles of the Cyanobacteria could not bear the external pressure. The buoyancy of the Cyanobacteria diminished until the floating force became smaller than its weight, causing the particles of the Cyanobacteria to settle. Under normal atmospheric pressure, the particle diameter was positively correlated to the floating velocity, while negatively correlated to the density. Under high pressure, the particle diameter was positively correlated to the subsiding velocity and the density. |
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