Mg-Cr layered double hydroxide (LDH) intercalated with sodium dodecyl sulfate as sorbent for Alizarine Red-S in aqueous solutions

Abstract

Mg 2+ /Cr 3+-LDH, (LDH-CO 3) with Mg/Cr molar ratio 2.0 and intercalated LDH with an anionic surfactant, sodium dodecyl sulphate, SDS-LDH were synthesized by co-precipitation method and was used for the sorption of Alizarine RedS (ARS) as anionic organic dye. The prepared adsorbents were characterized by FTIR, XRD, TGA and surface area. The influence of pH of the medium, shaking time, dye concentration and adsorbents dose on the sorption process were investigated. The kinetics of the sorption process was estimated using the pseudo first-order, pseudo second-order, intra particle diffusion and Elovich kinetic model. The results of LDH-CO 3 fitted well with the pseudo-firstorder model while the pseudo-second-order model fitted with SDS-LDH results. The obtained results indicated that the intercalation with SDS enhanced the sorption process and can be considered as a promising adsorbent for the removal of anthraquinone compounds from wastewater. Regeneration of the adsorbent was achieved using 0.1 M sodium hydroxide solution.