Study On Killing Of The Harmful Red Tide Algae With ·OH Based On Fluorescent Detection

In recent years, marine pollution has been becoming more and more serious with the rapid development of ocean shipping industry, coastal industy and agriculture and aquaculture in our country. It resulted in frequent outbreak of marine red tide disaster, caused serious negative effects on marine resources utilization and marine economic development, brought about great destruction of marine ecological environment, even endangered the human health. Therefore, how to efficiently control the marine red tide and reliably evaluate the killing effect has become hot topics in the study of marine environmental science.In this paper, solution of reactive oxygen species with a high concentration of hydroxyl radical (·OH) was prepared by atmospheric pressure strong electric-field discharge.We established a dead/alive and counting fluorescent staining method for two kinds of typical red tide algae(Skelrtonema costatum and Alexandrium tamarense) by fluorescein diacetate (FDA) and SYTOX Green nucleic acid stian. We focus on studying the dose effect of killing two kinds of typical marine red tide algae by hydroxyl radicals, and the damage effects of hydroxyl radicals on the chlorophyll of algae cells in order to provide new technology ideas and methods for the prevention and control marine red tide. We draw the Experimental results as follows:1. Experimental results show that when the concentration of FDA was 100μg/mL and the dyeing time was 10 minutes, the dyeing rate of Skelrtonema costatum (1.0 × 106cells/mL) was about 100%. When the concentration of SYTOX Green was 50uμM and the dyeing time was 10 minutes,the dyeing rate of Alexandrium tamarense (1.0 × 105cells/mL) was about 100%. Both methods can be applied to the detection of two algae density and activity after the treatment by hydroxyl radical.2. Hydroxyl radicals have a good effect to kill Skelrtonema costatum and Alexandrium tamarense. When the ratio of the concentration of hydroxyl radicals (TRO) were about 0.64mg/L,0.91mg/L and 1.64mg/L, the concentration of Skelrtonema costatum is 5.21×104cells/mL、10.11×104cells/mL and 20.21×104cells/mL can be reduced to the outbreak point (1.0×104cells/mL). When the ratio of the concentration of hydroxyl radicals (TRO) were about 0.73mg/L,1.86mg/L and 2.83mg/L,the concetrationd of Alexandrium tamarense is 1.05×104cells/mL、4.99×104cells/mL and 9.83×104cells/mL can be reduced to the outbreak point (1.O×103cells/mL)3. Hydroxyl radicals can kill algae cells by destroying the chlorophyll of red tide algae. When the ratio of the concentration of hydroxyl radicals (TRO) were about 0.59 mg/L,0.86 mg/L and 1.41 mg/L, the chlorophyll-a of the concentration of Skelrtonema costatum is 4.91 × 104cells/mL、10.23 × 104ells/mL and 19.87x 104ells/mL was decreased to such a degree are not found in the solution. When the ratio of the concentration of hydroxyl radicals (TRO) were about 1.12 mg/L,2.01 mg/L and 2.98 mg/L, the chlorophyll-a of the concentration of Skelrtonema costatum is 1.03×104cells/mL、 5.18×104cells/mL and 9.83×104ells/mL was decreased to such a degree are not found in the solution.Hydroxyl radical is a strong oxidant, it not only can quickly and efficiently kill the ride tide algaes, but does not produce secondary pollution of water.Hydroxyl radicals have long-term prospect of studying in controlling marine red tide.