Preparation of MgAl-LDH@PS Core-Shell Nanostructure as an Effective Approach for the Removal of Cr (VI) Pollutant

Chromium contamination in natural water has posed a significant threat to global health due to its toxicity and carcinogenicity. Adsorption technology is an easy and flexible method for chromium removal with high efficiency. Among these, the synthetic approaches based on nanotechnology due to unique structural characterization and application are of great importance. In this article, polystyrene (PS) nanoparticles were used as polymer support and magnesium-aluminum layered double hydroxide (MgAl-LDH) nanostructures were applied as adsorbent. The PS nanoparticles were synthesized via emulsion polymerization of styrene monomer. The as-prepared PS nanoparticles were used as the polymer support to be covered by the MgAl-LDH nanostructures prepared via a hydrothermal approach. The as-prepared MgAl-LDH@PS core-shell nanostructures are characterized by SEM, TGA, and FT-IR analysis. Batch adsorption of Cr(VI) was carried out to evaluate the adsorption efficiency, isotherm, and kinetic studies of the MgAl-LDH@PS nanostructures. On the basis of Langmuir model, a high maximum Cr(VI) adsorption capacity (Qmax) of 765 mg/g with coefficient correlation (R2) of 0.9951 was achieved in batch Cr(VI) removal study. Furthermore, based on the pseudo-second-order kinetic model, the pseudo-second-order rate of 0.1372 mg/(g min) with R2= 0.9975 was achieved. In addition, the results of the stability, as well as the regeneration of the adsorbent, showed that the MgAl-LDH@PS nanostructures can be considered unique adsorbent.