Study on adsorption properties and mechanism of thallium onto titanium‑iron magnetic adsorbent

Thallium (Tl) contamination caused by the industrial wastewater leakage has become a serious environmental problem due to thallium's high toxicity. In this study, a novel titanium‑iron magnetic nano-sized adsorbent was synthesized and applied for the effective removal of thallium(I). The physicochemical properties of the adsorbent were investigated by a series of techniques such as scanning electron microscope (SEM), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). About 83% of equilibrium adsorption capacity could be accomplished within the initial 30 min. The adsorption of Tl(I) was found to be highly dependent on solution pH. The maximum adsorption capacity of Tl(I) was 111.3 mg/g at pH 7.0. The presence of such co-existing cations as Na⁺, Mg²⁺, Ca²⁺ and Cu²⁺ could have a certain influence on the uptake of Tl(I). The adsorption mechanism was proposed as a surface complexation process of Tl(I) ions by binding to deprotonated sites of hydroxyl groups on the adsorbent surface. The prepared magnetic adsorbent would be suitable for effectively treating thallium-containing water due to its promising adsorption ability towards Tl(I) and ease in operation.