Inhibition of red tide microalgae by modified TiO2/expanded perlite photocatalyst

Abstract

Karenia mikimotoi is a classical red tide microalgae that causes red tide, which can cause water pollution and even death of animals and plants in water. In this experiment, the expanded perlite (EP) was used as a floating carrier, and floating photocatalysts were synthesized using three methods: hydrothermal synthesis, simple coating method and sodium alginate fixation method. The inhibitory effect of the floating photocatalysts synthesized by these three methods on the growth of K. mikimotoi was investigated. The experimental results showed that the floating photocatalyst formed by hydrothermal synthesis was the most effective for the inhibition of K. mikimotoi. The removal rate of algae reached more than 80% after 4 h. The content of chlorophyll a and soluble protein in K. mikimotoi decreased sharply after 1 h of floating photocatalyst. The floating photocatalyst prepared by hydrothermal synthesis destroyed the photosynthetic system of K. mikimotoi and caused the algae cells to lose energy source. The decrease of protein content reduced the metabolic activity of algae cells. This experiment provides a theoretical basis for the application of photocatalytic technology in the field of red tide control.

Keywords

• expanded perlite
• algae removal
• photocatalyst
• k. mikimotoi