TiO2 P-25 anatase rapid precipitation from water by use of struvite formation

UV360nm irradiation of TiO2 P-25 nanoparticle in water suspension is used for photocatalytic mineralization of pollutants or inactivation of microorganisms. Removal of TiO2 particles from large volumes of water following photocatalytic process is problematic due to their nano-size. So far no chemical methods are available for TiO2 rapid precipitation while filtration or centrifugation is not feasible because of high cost and limited performance. In the present study TiO2 was rapidly precipitated from water suspension by formation of the mineral struvite. Addition of Mg, P, and NH4+ at stochiometric rates of 1:1:1 at pH > 8.3 resulted in TiO2 entrapment into struvite formed flocs and rapid precipitation. Struvite sludge formed and precipitated was observed under HSEM revealing TiO2 entrapment into struvite mineral.

Precipitation of TiO2 colloidal particles in water suspension by struvite mineral formation.Figure optionsDownload as PowerPoint slide