One-pot preparation of layered double hydroxides-engineered boric acid root and application in wastewater

Abstract Heavy metals and organic pollutants are prevalent in water bodies, causing great damage to the environment and human beings. Hence, it is urgent to develop a kind of adsorbent with good performance. Anion interlacing layered double hydroxides (LDHs) is a promising adsorbent for the sustainable removal of heavy metal ions and dyes from wastewater. Using aluminum chloride, zinc chloride and ammonium borate as raw materials, the LDHs complex (BA-LDHs) of boric acid root intercalation was prepared by one-step hydrothermal method. The BA-LDHs samples were characterized by X-ray powder diffractometer (XRD), scanning electron microscope (SEM), Fourier transform infrared spectrometer (FT-IR) and gas physical adsorption analysis (BET). The results showed that borate was successfully intercalated. Adsorption experimental results suggested that BA-LDHs possess a maximum adsorption capacity of 18.7, 57.5, 70.2, 3.12 mg/g for Cd(II), Cu(II), Cr(VI) and Methylene blue (MB) at Cs = 2g/L, respectively. The adsorption experiment conforms to the Langmuir and Freundlich adsorption models and the kinetic adsorption data are well fitted by the pseudo-second-order adsorption kinetic equation. The as-prepared BA-LDHs have potential application prospects in the removal of heavy metals and dyes in wastewater. More importantly, it also provides a strategy for preparing selective adsorbents.