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

ABSTRACT

UV(360nm) irradiation of TiO(2) P-25 nanoparticle in water suspension is used for photocatalytic mineralization of pollutants or inactivation of microorganisms. Removal of TiO(2) particles from large volumes of water following photocatalytic process is problematic due to their nano-size. So far no chemical methods are available for TiO(2) rapid precipitation while filtration or centrifugation is not feasible because of high cost and limited performance. In the present study TiO(2) was rapidly precipitated from water suspension by formation of the mineral struvite. Addition of Mg, P, and NH(4)(+) at stochiometric rates of 111 at pH>8.3 resulted in TiO(2) entrapment into struvite formed flocs and rapid precipitation. Struvite sludge formed and precipitated was observed under HSEM revealing TiO(2) entrapment into struvite mineral.