Adsorption of reactive dyes onto polymeric adsorbents: effect of pore structure and surface chemistry group of adsorbent on adsorptive properties

A commercially available polymeric adsorbent NDA-99 and two new synthesized polymeric adsorbents NPA and AMR have been used for the adsorption of reactive dye (reactive brilliant blue XBR, abbreviated as XBR) from aqueous solution. The batch system was applied to study the adsorption equilibrium on the three polymeric adsorbents. Equilibrium adsorption data were obtained and fitted very well to Freundlich model. The results showed that the pore size distribution (PSD) and the amino groups on the polymer played a significant role in XBR adsorption performance, and polymer AMR exhibited the highest adsorption capacities due to the suitable PSD and the presence of amino groups. The free energy changes ΔG for adsorption of reactive dye XBR on the three polymeric adsorbents in the solution at 303 K were evaluated. The negative values of ΔG indicated overall adsorption processes were spontaneous and thermodynamically favorable.