Biomass ferulic acid-derived hollow polymer particles as selective adsorbent for anionic dye

In the present study, naturally occurring ferulic acid (FA) is used for the first time as raw material to copolymerize with maleic anhydride (MAH) for fabricating bio-based hollow polymer particles (BHPs). After consecutive reaction with ethylenediamine and HCl, BHPs were transformed to ammonium-functionalized BHPs (BHP-NH3+) which were identified by SEM, TEM, FT-IR and XPS measurements. BHP-NH3+ served as high-performance selective adsorbent for removal methyl orange (MO), a model anionic dye from water. Detailed adsorption studies reveal that the adsorption of MO onto BHP-NH3+ better fits the pseudo-second-order kinetics model and the adsorption isotherm can be well-described by Langmuir isotherm model with a maximum adsorption capacity of 952 mg/g at pH 7. The removal of MO can maintain a high level in a wide pH range (from 5 to 10). Desorption tests demonstrate that the adsorbent after adsorbing MO can be facilely regenerated to recover both the dye and adsorbent with high efficiency (over 95%) in basic solution (pH 11). Moreover, the biobased adsorbent shows high reusability and stability over five adsorption/desorption cycles.