Adsorption of cobalt(II) ion on prepared TiO2 adsorbents in high temperature water

Abstract

TiO2 adsorbents were prepared by hydrolysis of Ti(OC3H7)(4) followed by heat treatment of their hydroxides. Their structures were studied by X-ray diffractometry and Fourier transform infrared spectrometer as a function of preparation pH. The Co2+ adsorption characteristics of the adsorbent in high temperature water were investigated in a stirred autoclave. Co2+ adsorption capacity of the TiO2 adsorbent was determined to be 0.09 mEq/g adsorbent in 280 degrees C of high temperature water. The enthalpy change (Delta H degrees) of about 34 kJ/mol caused by the adsorption of Co2+ on the TiO2 indicates that the adsorption is endothermic in the experimental temperature range (150-280 degrees C). It was shown that specific surface area and surface OH groups of these adsorbents are not dominant factors for Co2+ adsorption on oxides at high temperature.