白光光照时间对船舶压载水中微藻电动运动速度的影响

The effect of white light illumination on the electrokinetic velocity of algae in ship’s ballast water

判定处理后船舶压载水中微藻的活性是压载水指示性检查的重要任务,死活微藻的表面电荷量不同,并且可由其电动运动速度来表征.本文选取等鞭金藻和小球藻开展实验,实验研究了紫外线灭活处理前后,经不同时间白光光照后,微藻在微通道中的电动运动速度.实验结果表明,在紫外辐照剂量为50 mJ·cm^(−2)处理下,微藻全部死亡;活死微藻表面均带负电,向电源正极运动.此外,在一定培养时间内,活体微藻的电动运动速度随光照时间的增加而增大,死亡微藻的速度随死亡时间的增加而降低.光照6 h后死活微藻的尺寸速度(速度乘以直径)差最大.本研究利用白光光照使微藻表面带电而产生的电动运动速度来表征微藻的死活情况,为压载水处理后判定微藻活性提供了一种新思路.

Determining the activity of microalgae in treated ship ballast water is an important task in ballast water indicative examination.The surface charge of dead and live microalgae varies and can be characterised by their electrokinetic velocity.In this paper,experiments were carried out with Isochrysis galbana and Chlorella vulgaris to investigate the electrokinetic velocity of microalgae in the microchannel before and after UV inactivation treatment and after different times of white light exposure.The results showed that all microalgae died under the treatment of UV irradiation dose of 50 mJ·cm^(−2);all the living and dead microalgae were negatively charged on the surface and moved towards the positive pole of the power supply.In addition,the electrokinetic velocity of live microalgae increased with increasing light time and the velocity of dead microalgae decreased with increasing death time within a certain incubation time.The difference in size velocity(velocity times diameter)between dead and living microalgae was greatest after 6 h of light.In this study,the velocity of electrokinetic movement of microalgae due to the electrification of their surface by white light illumination was used to characterize the dead and alive microalgae,providing a new idea for determining the activity of microalgae after ballast water treatment.