Hydrous TiO₂ materials and their application for sorption of inorganic ions

The work is devoted to preparation of hydrous TiO₂ adsorbent samples, their characterization, determination of adsorption isotherm types for Zn(II) and Pb(II), choosing the best adsorbent sample and measurement of its capability to purify flow of water from As(V), Bi(III), Cd(II), Co(II), Cr(VI), Pb(II), Th(IV), U(VI), V(V) and Zn(II). 10 adsorbent samples were synthesized by hydrolysis of TiOSO₄ and TiCl₄ in aqueous ammoniac, the highest surface area being 620m²/g. Adsorption over TiO₂ of Zn(II) follows Sips isotherm whereas that of Pb(II) follows Freundlich isotherm, both isotherms converge into Freundlich isotherm at low concentrations. Using Pb(II) adsorption, the best TiO₂ adsorbent was chosen that has adsorption capacity 293mg/g at concentration equal to maximum allowable concentration (MAC). This adsorbent purifies water from Co(II), Zn(II), Pb(II), U(VI), Th(IV) and Cd(II) during single pass through column to below MAC. Purification from Cr(VI), V(V), Bi(III) and As(V) required preliminary washing the adsorbent with HNO₃ solution.