Removal of Chattonella marina with clay minerals modified with a gemini surfactant

With the frequent occurrence and negative impacts of harmful algal blooms (HABs) on coastal countries throughout the world, it is urgently needed to find ways to control HABs effectively. Vermiculite, montmorillonite, palygorskite, and kaolin were modified with a Gemini surfactant to explore a new algaecide for controlling HABs. The removal efficiency of the modified clay minerals was evaluated with Chattonella marina, a typical HAB alga in China. Gemini modified vermiculite (G-VER) exhibited the highest removal rate against C. marina. When the concentration of G-VER (21.1% Gemini) was 6.5 mg/L, the removal rate reached to 100%. Dispersed in sea water for 72 h, only 3% of Gemini was released from the G-VER, indicating that the modified clay minerals had good stability in sea water and caused low impacts in the aquatic environment. G-VER is considered a potential algaecide with high efficiency and environmental safety.

Research Highlights
► To explore a new algaecide for controlling HABs, four clay minerals modified with a Gemini surfactant were prepared, and their removal efficiency was evaluated with Chattonella marina, a typical HABs alga in China.
► The removal efficiency of modified clays depends on the synergistic reaction of clay type, particle size, Zeta potential and the amount of Gemini in the modified clays.
► G-VER is a potential algaecide with high efficiency and environmental safety.