Preparation, Characterization, and Boron Adsorption Behavior of Gluconate-Intercalated Hydrotalcite

摘要

Gluconate-intercalated hydrotalcites were prepared from precursor by ion-exchange method. The products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and energy dispersive spectroscopy (EDS) studies. This kind of new adsorbent was applied to adsorb boron in the refined brine, and the conditions influencing its adsorption amount were investigated. The experimental results showed that the adsorbent synthesized in this article had higher adsorption amount of boron than the precursor without gluconate intercalation, and the adsorption amount increased with increasing the contact time, boron concentration, and the pH whereas decreased with increasing chloride concentration and temperature. The adsorbent can be well regenerated by calcination and reintercalation of the gluconate into the calcinated product. Furthermore, the kinetic studies were also investigated. The pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were used to fit the experimental data, and the results showed that the pseudo-first-order model best described the boron adsorption process.