| Title |
Sinking Behavior of Freshwater Diatoms - With Special Reference to Measurement of Phytoplankton Sinking Bate - |
| Authors |
이주동 ( Ju Dong Lee ) ; 최상준 ( Sang June Choi ) ; 김영훈 ( Young Hun Kim ) ; 김한순 ( Han Soon Kim ) ; 이정호 ( Jung Ho Lee ) |
| Abstract |
Sinking behaviors of four freshwater diatoms were studied at various conditions (lightning, natural, killed and cultivated in laboratory). Water samples containing diatoms were collected from the Naktong River and the sinking rate of each species was measured by simple equation derived as function of the difference between the initial concentration and the final concentration in the lower part of the settling cylinder. Synedra acus, Aulacoseira sp., Stephanodiscus sp. and Asterionella Formosa were major phytoplanktonic diatoms in the river and each diatom species had constant sinking rate according to the fixed conditions. In natural condition (2000 Lux), the sinking rate was 10.80 mm hr^-1 for Synedra acus, 11.20 mm hr^-1 for Aulacoseira sp., 18.27 mm hr^-1 for Stephanodiscus sp. and Asterionella formosa had different values (11.66-15.70 mm hr^-1) in proportion to the cell numbers forming colony. Especially, in the dark condition, the sinking rates were faster than under the lighting condition, and moreover, killed diatom species sank faster than living ones. Ultimately, the sinking behavior of the species studied here applied to pilot test. The result of pilot tests indicated that the sinking characteristics of the diatoms had positive correlations with their removal efficiencies in drinking water treatment. |