Study On The Effect Of Killing Algae And Removal Of Microcystin-LR By Electro Catalytic Oxidation

During the last two decades, the study of cyanobacteria (blue-green algae) has been attracting attention because of its increasing importance in agriculture, environmental conservation, pollution control ,pharmaceutical industry. In this paper, to solve the pollution problem in water, the applicability of electro catalytic oxidation on killing algae and microcystin-LR removal was examined using Ti/RuO₂ as anode, at the same time explored the viability determination of blue-green algae by FDA-PI double staining.It can be concluded that anodic electro catalytic oxidation is quite an efficient method to kill algae and remove microcystin-LR from the water. The results showed that when the cell density decreased and the applied current increased, the efficiency of algae cell decay and microcystin-LR removal increased. Algae cell in Guanting Water can be killed by electro catalytic oxidation even the cell density is very low and the water without adding any electrolyte. The result showed that the dissolved organic carbon in the water decreased markedly after electro catalytic oxidation and the technique can be applied to water treatment.The paper studied the viability determination of two kinds of algae Anabaena flos-aquae and Microcystis aeruginosa by FDA-PI double staining. Fluorescence emission from cells was measured by fluorescence microscopy. The results indicated that viable and dead cells were stained as bright green and red fluorescent cells respectively by fluorescein diacetate and propidium iodide under blue excitation(495nm). The staining rate has relation with the cell density. If the cell density of Microcystis aeruginosa and Anabaena flos-aquae was 6×10⁷⁷xl0⁹L^-1 and 4 × l0⁷⁵×l0⁸ L^-1, the FDA staining rate would be more than 94% and 91%. But if the cell density of Anabaena flos-aquae increased to 5×10⁹L^-1, the staining rate would fall to 67% obviously due to cell twisting together. The staining rate of PI can reach 100% for the two kinds of algae. Based on the fluorescent light from cells, it can be easy to determinate the cell viability. FDA-PI double staining method is a new method to measure the algae cell viability.