Uranium uptake from wastewater by the novel MnxTi1-xOy composite materials: performance and mechanism

Abstract The novel MnxTi1-xOy composite materials with different mole ratios (Mn to Ti = 3:7, 5:5 and 7:3) were prepared to remove uranium species from wastewater. These composite materials were characterized by various techniques, such as thermogravimetric analysis (TG), X-ray diffraction (XRD), Fourier transformed infrared (FT-IR) and scanning electron microscopy (SEM). It was found that the chitosan in MnxTi1-x-Chi were completely removed after calcination at 650 °C and MnxTi1-xOy composites possessed uniform distribution of the porous structure as well as plentiful hydroxyl-containing groups. Moreover, the as-prepared MnxTi1-xOy composite materials were applied to remove uranium from solution to evaluate the adsorption performance. It was found that the Mn0.5Ti0.5Oy possessed relatively excellent uptake performance for uranium comparing with the Mn0.3Ti0.7Oy and Mn0.7Ti0.3Oy and its maximum uptake capacity and efficiency reach 695.2 mg/g and 98.6% (pH = 4, m/V = 0.1 g/L, T = 298 K), respectively, which were much superior than most of reported materials based on titanium oxide or manganese oxide. Besides, the uranium uptake on Mn0.5Ti0.5Oy was independent on ionic strength and it had considerable reusability, which might be the necessary condition for Mn0.5Ti0.5Oy to be applied in uranium uptake from uranium-containing wastewater. As a candidate adsorbent, Mn0.5Ti0.5Oy possessed a high potentiality to remove uranium from wastewater.