Magnetic Prussian Blue derivative like absorbent cages for an efficient thallium removal

Environmental thallium concentration has been increasing due to anthropogenic events making the development of Tl(I) adsorbents an area of interest for materials science researchers. This report proposes a new composite based on a Prussian Blue derivative and magnetite nanoparticles for thallium(I) removal. Additionally, extensively characterization by FTIR-ATR, TGA, XRD, TEM/SEM, XPS, BET, and Magnetization were performed. The Tl(I) removal capacity from simulated wastewater was evaluated as well as the influence of different experimental conditions. The maximum experimental sorption capacity was 117 mg of Tl(I) per gram of composite after 21 h of interaction. The Tl-loaded composite was recovered by means of magnet achieving a final Tl concentration in the medium 28 times lower than the permitted limit for wastewaters. The removal process is independent of the pH with slight interferences of typical ions contained in wastewaters of the mining industry. The sorbent is reusable with non-significative variations of the thallium sorption capacity allowing to recover 97% of removed thallium under KCl solution desorption treatment. Moreover, the magnetic composite showed potentialities for multiple metals adsorption, like Cu and Pb removal. The main mechanism involved in the separation of Tl(I) is a K–Tl ionic exchange described by a pseudo-second-order and intra-particle diffusion kinetics. Herein, a new sorbent material easy to prepare, low-cost, reusable and eco-friendly is presented for effective magnetic thallium removal and recovery from wastewaters.