Magnetic FeS@Lignin-derived carbon nanocomposites as an efficient adsorbent for multistage collaborative selective recovery of tellurium (IV) from wastewater

Abstract Fabrication of an acid-resistant, biodegradable and recoverable highly efficient adsorbent to selectively recover tellurium resources from acidic wastewater for minimizing their threat still presents a significant challenge. Herein, a sheet-like magnetic FeS@Lignin-derived carbon (FeS@LC) nanocomposite with acid-resistant was obtained as an efficient adsorbent for tellurium separation through a simple two-step hydrothermal reaction. The results indicated that this FeS@LC fabricated with biodegradable lignin-derived carbon (LC) and highly reactive FeS revealed a superior adsorption capacity (148.36 mg/g) for tellurium. Isotherm and kinetic results suggested that the tellurium adsorption process was dominated by a monolayer chemisorption process. The thermodynamic parameters for tellurium adsorption on FeS@LC confirmed that the tellurium adsorption was exothermic and spontaneous. Precipitation, reduction, ion exchange, and surface complexation are regarded as the main adsorption mechanisms for tellurium purification. Besides, FeS@LC composites can selectively adsorb tellurium from a multitude of coexisting ions. Meanwhile, the FeS@LC maintained quick magnetic recyclable capability (10S) and excellent adsorption performance (108.87 mg/g) after five consecutive adsorption-desorption. Importantly, FeS@LC exhibited a superior stability and antifouling properties, facilitating its practical application in complex environments. Therefore, this work expands the application field of lignin-derived carbon-based materials, presenting a bright application for similar pollutants purification in wastewater.