Water defluoridation using a nanostructured diatom-ZrO₂ composite synthesized from algal Biomass

Frustules or the rigid amorphous silica cell wall of unicellular, photosynthetic microalgae with unique porous architecture has been used to synthesize a composite by immobilizing ZrO₂ on its surface and in the pores. This was effective in water defluoridation. The average diameter of the composite was 80±2nm and surface area was 140m²/g. The adsorption isotherms followed both Langmuir and Freundlich models, and the composite was regenerable. Adsorption kinetics followed second order model and the adsorption capacity was as high as 11.32mg/g, while the Langmuir maximum adsorption capacity (q_m) reached 15.53mg/g. The research findings highlight the potential of diatoms as hosts for nanomaterials for use in water treatment.