Synthesis and characterization of magnetized ETS‐4 modified with lanthanum and iron for fluoride adsorption

다국어 초록 (Multilingual Abstract)

In this work, two adsorbents were synthesized by loading lanthanum and iron ions on magnetized ETS‐4 titanosilicate. The sorbents were identified by Fourier‐transform infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), thermogravimetry, differential thermogravimetry (TG‐DTG), X‐ray diffraction (XRD), and Brunauer‐Emmette‐Teller techniques, and their adsorption performance for the sorption of fluoride was evaluated in a wide fluoride concentration range. The influence of various variables, including shaking time, fluoride concentration, pH, and temperature, on the uptake of fluoride was investigated. The maximal capacity of ETS‐4 impregnated with La and with Fe was 260.69 and 231.43 mg/g, respectively. The used sorbent was readily removed from the solution by using a magnet bar. The regenerated sorbent retained most of its capability after regeneration. The results of the kinetic study were described by a pseudosecond‐order model, indicating that the process was chemisorption in nature. The Freundlich isotherm well described the sorption data, which implied that the adsorption was multilayered and heterogeneous.