Elsevier, Chemical Engineering Science, (124), p. 170-178, 2015
DOI: 10.1016/j.ces.2014.07.017
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Three zeolitic imidazolate frameworks (ZIF-8, ZIF-90 and ZIF-93) were investigated for adsorption of 5-hydroxymethylfurfural (HMF) from aqueous solution. The equilibrium uptake of HMF decreased following the order of ZIF-8 (465 mg g−1)>ZIF-90 (307 mg g−1)>ZIF-93 (279 mg g−1), in accordance with the hydrophobicity of the frameworks. The adsorption equilibrium data were found to follow Langmuir adsorption model. The sorption kinetics could be well described by the pseudo-second-order kinetic equation. The HMF-loaded ZIFs could be fully regenerated with ethanol as the desorption solvent. Selective adsorption of HMF from HMF/fructose/water mixtures was also carried out. The uptake of HMF remained unchanged, with no observable adsorption of fructose. In liquid phase breakthrough experiments, the uptake of HMF on ZIF-8 in column was consistent with the batch study. Furthermore, the ZIF-8 packed column could be regenerated effectively and recycled with no discernible loss of adsorption capacity. These findings confirm that ZIF-8 can be employed as an effective and reusable adsorbent for HMF recovery from aqueous solution.