Ti(IV) hydrogenphosphates were prepd. by their pptn. from aq. solns. of TiOSO(4) with H(3)PO(4) at 85 degrees C and drying at 70 degrees C, analyzed by X-ray diffractometry and thermogravimetry and then used successfully for adsorption of Ni(II) ions from their aq. soln. at 25 to WC. The Freundlich and Langmuir isotherms of sorption were detd. at varying Ni(II) concn. (up to 0.07 mln/L to det. the thermodn. parameters (free energy, enthalpy, entropy) of the sorption. The equil. concn. was achieved after less than 1 h. The TiOSO(4) raw material was originated from com. prodn. of TiO(2) by the sulfate method.