Fe-Mn binary oxides activated aluminosilicate mineral and its Tl(I) removal by oxidation, precipitation and adsorption in aqueous

Abstract

Thallium mainly exists in monovalent state Tl(I) in aqueous, and its removal usually requires multiple treatment processes, including oxidation, precipitation, flocculation and so on. A Fe-Mn binary oxides activated aluminosilicate minerals (FMAAM) was prepared by hydrothermal synthesis of active aluminosilicate minerals (AAM), KMnO4 and Fe(NO3)3, and used for one step removal of Tl(I). Its physicochemical properties, adsorption capacity and mechanisms were investigated, compared with activated aluminosilicate minerals. FMAAM had a mesoporous structure (5.444 ​nm) with a specific surface area of 73.41 ​m2/g, which is much larger than 0.1651 ​m2/g of AAM. FMAAM exhibited excellent performance for Tl(I) adsorption under a broad pH (3–10), the maximum adsorption capacities was 78.06 ​mg/g, compared with 14.28 ​mg/g of AAM (at 25°C, pH=7, a dosage of 1 ​g/L). Scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), fourier transform infrared spectroscopy (FTIR) and x-ray photoelectron spectroscopy (XPS) were used to characterize the absorbents before and after Tl(I) adsorption. Ion exchange, oxidation and precipitation and surface complexation were the main forces for Tl(I) removal.