Study on dynamic adsorption of p-nitrophenol by multi-walled carbon nanotubes dispersed cyclodextrin

In this paper, the modified multi-walled carbon nanotubes were prepared by beta-cyclodextrin denoted as beta-CD-MWNTs. The structure and morphology of beta-CD-MWNTs was characterized by TEM and the dynamic adsorption of p-nitrophenol on beta-CD-MWNTs was studied by the Thomas model. Some affecting factors of dynamic adsorption and the adsorbent regeneration process such as the sewage concentration, the amount of absorbent in column, including the type of reagent, solid-liquid ratio, regeneration time, and regeneration times were investigated and optimized. The results indicated that the p-nitrophenol removal rate could reach 84% under stuffing 2 g beta-CD-MWNTs. The curves of p-nitrophenol's dynamic adsorption conformed to the Thomas model. Moreover, the adsorption capacity of regenerated beta-CD-MWNTs was similar to the fresh beta-CD-MWNT column. The optimal conditions of regenerations of beta-CD-MWNTs were shown as follows: the type of reagent is anhydrous ethanol, the solid-liquid ratio is 200:40 (mg/mL) and the regeneration time is 120 min.