Removal of bisphenol A using Mg-Al-layer double hydroxide and Mg-Al calined layer double hydroxide

Mg-Al-layer double hydroxide (Mg-Al-LDH) was synthesized and calcined to obtain Mg-Al-calcined-layer double hydroxide (Mg-Al-CLDH). In contrast to Mg-Al-LDH, Mg-Al-CLDH had a large adsorption capacity for bisphenol A (BPA) and bisphenol AF (BPAF). The maximum adsorption capacities of Mg-Al-CLDH for BPA and BPAF were 216.5 and 337.6 mg/g, respectively. By measurement of X-ray diffractometry, scanning electron microscopy, and Fourier transform infrared spectroscopy with the time processing, Mg-Al-CLDH was regenerated to Mg-Al-LDH-like structure and this means the structure memory effect is the main mechansim for adsorption of BPA and BPAF. The effects of initial pH, temperature, anions, ionic strength, and reusability on the adsorption were also discussed.