Research on the preparation of iron-titanium-manganese composite and its adsorption properties for thallium in wastewater

Thallium-containing wastewater will be generated during the preparation of lithium carbonate from lithium mica, posing a serious pollution risk to the surrounding environment, wastewater containing high concentration of thallium is produced. In this paper, a new type of iron-titanium-manganese composite material was prepared by coprecipitation and calcination methods, and it was used as an adsorbent for the efficient removal of thallium from wastewater. The optimal adsorption conditions of the composite material, adsorption kinetics and the influence of coexisting ions on the adsorption effect of thallium were studied. The adsorbent was systematically characterized and the mechanism was analyzed by means of X-ray diffraction, scanning electron microscopy, nitrogen adsorption-desorption analyzer and Zeta potential detection. The results show that the iron-titanium-manganese composite material has abundant active sites and oxygen-containing groups, the specific surface area reaches 25.74 m²/g, and the pore structure is developed. It shows excellent adsorption performance for thallium in a wide pH range, and the removal rate of thallium reaches 96%~99%. In addition, in the presence of other ions (such as Na⁺, Ca²⁺, Mg²⁺) and organic substances (such as EDTA), the material still shows strong selectivity. The calculation results of Langmuir and Freundlich models show that the maximum adsorption capacity of the composite material for thallium at room temperature is 71.85 mg/g, and the adsorption kinetics conforms to the pseudo-second-order model.