Polystyrene microspheres-templated preparation of hierarchical porous modified red mud with high rhodamine B dye adsorption performance

Modified red mud (MRM-PS) with a hierarchical macroporous-mesoporous structure was prepared via a template synthesis method by using polystyrene (PS) microspheres and waste red mud. The textural and morphology of the as-prepared MRM-PS adsorbents were characterised by X-ray diffraction, scanning electron micrographs, transmission electron microscopy and N₂ sorption techniques. The analysis results revealed a hierarchical macroporous-mesoporous nanoparticle system with high surface area and uniform pore-size distribution. The results of adsorption performance measurements showed that the rhodamine B adsorption on the prepared MRM-PS adsorbent was a fast process and the equilibrium was reached in 10 min. What is more, the adsorption capacity of MRM-PS was found to be 59.37 mg dye·g^-1 of adsorbent at 25°C and pH = 1. Thus, utilisation of industrial solid wastes such as red mud for the treatment of wastewater could help in the abatement of environmental pollution, in solving both solid waste disposal and liquid waste problems.