Temperature effect on the sorption of borate by a layered double hydroxide prepared using dolomite as a magnesium source

• Layered double hydroxide was synthesized by using a natural source of Mg (D-LDH).
• Effect of calcination temperature on the sorption of borate was carefully studied.
• Higher sorption density of borate was observed at higher calcination temperature.
• The sorption mechanism of borate by D-LDH was explored and proposed.

A hydrotalcite-like compound prepared through chemical deposition using calcined dolomite as the magnesium source (D-LDH) was applied to remove borate. D-LDH calcined at different temperatures was characterized by specific surface area measurements, scanning electron microscope images, X-ray diffraction (XRD) patterns, and Fourier transform infrared (FTIR) spectra to optimize the calcination temperature and maximize the sorption capacity of borate. Greater sorption density of borate was observed at higher calcination temperature, and the sample calcined at 700 °C showed the maximum sorption density. In addition, the sorption density of borate by D-LDH calcined at 700 °C decreased with increasing initial pH. The solid residues after the sorption of borate were characterized by FTIR, 11B NMR (11Boron nuclear magnetic resonance), and XRD to explore the sorption mechanism of the calcined product at 700 °C.