Effective removal of brilliant green from aqueous solution with magnetic Fe3O4@SDBS@LDHs composites

The magnetic composite-materials (Fe3O4@SDBS@LDHs) were prepared by sodium dodecyl benzene sulfonate (SDBS) modified layered double hydroxides (SDBS@LDHs) with Fe3O4 via co-precipitation method. The results of XRD, FT-IR and SEM/EDS indicated that the dispersibility of LDHs was improved, and the modification of SDBS took place on the surface of LDHs. The adsorption capacity of Fe3O4@SDBS@LDHs to brilliant green (BG) reaches 329.1 mg/g after the adsorption equilibrium. The thermodynamic parameters indicated that the adsorption process was endothermic and spontaneous, and the rate of a reaction increased with the raise of the reaction temperature. The Langmuir model was applicable for describing the sorption isotherms, indicating that the adsorption process is a monolayer adsorption. The results of kinetics study showed that adsorption fitted the pseudo-second order model well. The adsorbents still have good adsorption performance after four adsorption cycles. Moreover, the magnetic composite could be easily separated from aqueous solution. This indicated that Fe3O4@SDBS@LDHs can be considered as potential adsorbents in environmental applications for the removal of BG from aqueous solutions.