Preparation of cerium-modified tobermorite and its application for Cr³⁺ and Cu²⁺ ions removal

Abstract

With the rapid development of industrial activities such as electroplating, metallurgy and printing and dyeing, a large volume of wastewater containing typical heavy metals including Cr³⁺ and Cu²⁺ is discharged into the environment. Therefore, the development of efficient and stable heavy metal adsorbent materials is critical for environmental management. This study investigates the preparation method, influencing factors and adsorption mechanism of cerium-modified tobermorite. Through batch static adsorption experiments, model fitting and comprehensive characterization using XRD, FTIR and SEM-EDS, it is determined that the sample modified with 0.05 mol/L Ce exhibits the optimal performance. The modified material can well retain the three-dimensional network structure of tobermorite, and Ce elements are uniformly distributed on the material surface. Under the conditions of a heavy metal solution pH of 6, an initial concentration of 100 mg/L, a material dosage of 1.0 g/L, and a reaction time of 60 min, the removal rates of Cr³⁺ and Cu²⁺ reach as high as 99.08% and 99.76%, respectively. The maximum adsorption capacity of the modified tobermorite for heavy metals exceeds 99 mg/g. After Ce modification, active sites can be introduced, and the silicon-oxygen framework participates in interfacial complexation, which further enhances the adsorption and immobilization effect for heavy metals, with heavy metal ions uniformly and dispersedly distributed on the material surface.